Helicobacter pylori infections are still an urgent and hot topic. This is related to the involvement of H. pylori in human diseases (including gastric diseases, gastric adenocarcinoma, mucosa-associated lymphoid tissue lymphoma, and diabetes), the number of which is constantly increasing. At the same time, agents effective against these bacteria are decreasing due to spreading resistance. Our research focused on extracts of the Rubus genus, commonly present in Central and Eastern Europe and very useful in folk medicine. Results have shown that the extract from Rubus idaeus 'Willamette' shoots, and the extract from R. idaeus 'Poranna Rosa' fruits and R. idaeus 'Laszka' R. occidentalis Litacz' fruits prevent the formation of biofilm by H. pylori on intravenous infusions (they reduce living cells, which was detected using triphenyl tetrazolium chloride (TTC) as a dye) at concentrations of 6.65 and 16.65 mg/mL, respectively. However, the living bacteria in the formed biofilm are affected by the extract from the shoots of R. idaeus 'Willamette' and the fruit of R. idaeus 'Poranna Rosa' at a concentration of 16.65 mg/ml, and the remaining extracts at a concentration of 33.3 mg/ml. The results of the study of interactions of extracts from Rubus sp. and the 2 antibiotics against H. pylori planktonic bacteria showed doxycycline synergism with all tested extracts, but only the extract of R. occidentalis 'Litacz' with levofloxacin. The remaining tested extracts showed indifference with levofloxacin. However, studies on the interaction between antibiotics and extracts of R. idaeus 'Willamette' shoot showed synergy with doxycycline and levofloxacin, additivity with amoxicillin and clarithromycin, and indifference with metronidazole. The tests were carried out on fragments of intravenous infusions with TTC as a dye. The tested extracts may be elements of broadly understood anti-H. pylori therapy.

Terminalia arjuna possesses significant cardio protective, antidiabetic and antioxidant properties as these properties are described in Ayurveda. In the present study, three flavonoids were isolated through the separation and chromatographic purification of the whole plant material of T. arjuna. Spectroscopic characterization identified one of them as a new flavonoid “Terminalone A (1)” and two known flavonoids i.e. 6-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one (2) and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4H-chromen-4-one (3). The bioactivity studies showed considerable antibacterial and antioxidant (DPPH was used as a scavenger) potential for all the three compounds 1-3 where the compound 1 showed strong antibacterial and antioxidant activity.

To reveal the antibacterial effect of wound secretions of different Chinese fir strains on five kinds of bacteria. Three 3-year-old seedlings of Taxus chinensis var.koraiensis and Yangkou and the 3-year-old container seedlings of Taxus chinensis var.pendula, Yang061 and Yang020, were used as the research objects. The antibacterial effect of wound secretions was determined by the filter paper diffusion method, and the antibacterial effect was analyzed. Results showed that the wound secretions of different strains of Chinese fir bark had noticeable bacteriostatic effects on Bacillus subtilis, Salmonella paratyphi B, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. However, the bacteriostatic effects of different strains of Chinese fir secretions differed. The minimum inhibitory concentrations (MICs) of the wound secretions of different strains of Chinese fir against the five test bacteria differed. The mean MIC of Pseudomonas aeruginosa was the highest, and the mean MIC of Escherichia coli was the lowest. The antibacterial ability of the wound secretions of different Chinese fir strains was mainly determined by the composition of the wound secretions. There was no noticeable relationship with the number of wound secretions.

By slowly evaporating 4-bromo-2-methylbenzonitrile at room temperature, it was possible to make a single organic nonlinear optical crystal. The grown crystal's crystalline nature was verified, and the unit cell characteristics are provided as a = 4.08Å, b = 6.61 Å, c = 28.93Å, α = 90º, β = 90º, γ = 90º. The functional groups of the crystal produced were identified using the FTIR and FT-Raman spectra. The UV cutoff wavelength is found at 221.6 nm, and the transparency nature of the crystal was analyzed in the optical studies.  The band gap of the grown crystal was estimated using the Taucs’ plot. The violet and red emissions of photoluminescence are discussed. A high dielectric constant was received at a low frequency. The TG/DTA curve shows that the grown crystal was stable up to 125.59 ºC.  The Kurtz-Perry powder technique was applied to confirm the Second Harmonic Generation's (SHG) nature. By using the agar diffusion method, the antibacterial property of the grown 4B2MBN crystal was determined.

Background: The use of nitinol (NiTi) archwires in orthodontic treatment has expanded significantly due to unique mechanical properties. The greatest barrier to safe orthodontic treatment is chemically or microbiologically induced corrosion, resulting in Ni2+ release. The aim of this investigation was to enhance corrosion resistance and introduction antibacterial properties to NiTi archwire by coating them with TiN-Cu. Methods: NiTi archwires were coated with TiN-Cu using cathodic arc evaporation and direct current magnetron sputtering. The morphology of the sample was analyzed by FESEM and the chemical composition was assessed using EDS, XRD and FTIR. Inductively coupled plasma-optical emission spectrometry was used to estimate the ion release. Biocompatibility of samples was investigated using MTT test. Antibacterial activity was analyzed against Streptococcus mutans and Streptococcus mitis. Results: Physico-chemical characterization revealed well-designed coatings with the presence of TiN phase with incorporated Cu2+. TiN-Cu coated archwires showed statistically lower Ni2+ release (p<0.05). Relative cell viability was the highest regarding 28-day eluates of TiN-Cu coated archwires (p<0.05). The most remarkable decrease in Streptococcus mitis concentrations was observed in case of TiN-Cu coated archwires (p<0.05). Conclusion: Taking into account biocompatibility and antibacterial tests, TiN-Cu coated archwires may be considered as a good candidate further clinical investigations.

Chemical investigation of the Chinese soft coral Lobophytum sp. has resulted in the isolation of six new compounds, namely lobosteroids A–F (1–6), along with four known compounds. Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data reported in the literature. Among them, the absolute configuration of 1 was determined by X-ray diffraction analysis. These steroids characterized by either the presence of an α,β-αꞌ,βꞌ-unsaturated carbonyl or an α,β-unsaturated carbonyl moiety in ring A, or the existence of a 5α,8α-epidioxy system in ring B, as well as diverse oxidation sites of side chains. The prelimi-nary antibacterial bioassay showed all compounds exhibited significant antibacterial activities against the fish pathogenic bacteria Streptococcus parauberis FP KSP28 and Phoyobacterium damselae FP2244 with all inhibition rates more than 90% at the concentration of 150 µM. And at the same concentration, compounds 2, 6–10 also displayed potent inhibitory effects against vancomy-cin-resistant Enterococcus faecium bacteria G7 with all inhibition rates more than 90%.

Introduction: Among the many factors that may limit effective wound healing in patients with chronic ulcers, bacterial infection and poor cell recruitment are primary causes that contribute to prolonged healing. Thus, a novel strategy that aims to prevent bacterial infection within the wound, while at the same time providing structural scaffolding that promotes endogenous tissue repair, would be of great interest. Here, we developed a thermo-sensitive silver nanoparticle hydrogel composite as an antibacterial nutritional scaffold for the wound that contains all nutrients required for cell growth while preventing bacterial infection with the ability to fill up all the cavities and void areas in wounds regardless of their geometry. Methods: Silver nanoparticles (AgNPs) were synthesized by chemical reduction. After characterization, silver hydrogel nanocomposite was developed by reconstitution of collagen-based hydrogel powder in a nanoparticle suspension of varying AgNPs concentrations (200, 400, and 600 ppm). The antibacterial activity of the formulations was examined in vitro and in vivo in subcutaneous implant infected model. The wound healing efficacy of the hydrogel nanocomposite was also evaluated using a splinted wound model in rats through comparison of clinical wound measurements and histological assessments. Cytocompatibility assay and biochemical analysis of blood at the end of in vivo wound healing study were performed to evaluate the safety of formulations. Results: The synthesized nanoparticles were spherical and stable. While hydrogel alone did not show any bacterial reduction in vitro, the inhibition of bacterial growth was significant in all silver hydrogel nanocomposites compared to controls (p <0.05) and was dose-dependent, with maximum reduction observed in the 600 ppm group (4.56±0.26 LOG CFU/mL, P<0.001). All concentrations of AgNPs hydrogel composites showed significant antibacterial activity in vivo as well (P<0.0001). Treatment of splinted wounds with AgNPs hydrogel composite resulted in faster wound closure and accelerated wound re-epithelialization. The formulations were non-cytotoxic and did not differ significantly in hematological and biochemical factors from the control group in in vivo study. Conclusions: By presenting promising antibacterial and wound healing activity, silver hydrogel nanocomposite offers a safe therapeutic option that can be used as a functional scaffold for an acceleration of wound healing.

Over the years, chitosan has been the subject of numerous studies and has gained significant popularity as a biomaterial due to its various characteristics, including biocompatibility, biodegradability, and bioactivity. In this work, chitosan fibres surface was modified with ursolic acid to improve their antibacterial properties by wet impregnation method. Five specimens of chitosan fibres were immersed in ursolic acid (UA) solution for varying immersion times of 1, 2, 4, 6, and 8 hours. Characterization was carried out by means of FTIR, SEM, UV-Vis spectroscopy; the results indicated an ongoing chemical reaction between chitosan and ursolic acid resulting in changes to the chemical structure. After 2 hours, the absorbance ratio remained constant; suggesting that the reaction had reached completion and the chemical structure of the sample remained stable. Antibacterial tests were performed on the resulting chitosan fibres against two bacterial strains. The fibres without ursolic acid did not exhibit any noteworthy antibacterial activity against either strain. However, the chitosan fibres modified with ursolic acid showed significant and almost strong antibacterial activity against the Gram-positive strain, S. aureus. These results suggest that chitosan fibres modified with ursolic acid could have potential applications as antibacterial materials, particularly against Gram-positive bacteria.

Jade waste is a normal byproduct that makes up much more than the amount of jade extracted. Therefore, recycling jade waste is worth investigating from the point of view of energy conservation. Moreover, it is an environment-friendly material, which is desirable for use in building materials. In this study, Xiuyan jade waste was repurposed as antibacterial additives for building coatings. The powder waste was activated by milling and subsequent annealing. The antibacterial properties of the treated waste were mostly related to the annealing temperatures. Based on the investigations of the phase change and the release of metal ions of a series of samples and their antibacterial activities, the antibacterial mechanism of the treated samples was explored experimentally. The most applicable sample for coatings was finally chosen by considering its pH values and its antibacterial abilities. Antibacterial testing showed that the addition of treated jade waste could enhance the bacterial inhibition rate of building coatings from 60% to 99.9%.

Biocidal compositions based on interpolyelectrolyte complexes and a low molecular weight antibiotic can become a promising material for creating biocidal coatings, as they combine wash-off resistance and dual biocidal action due to the biocide and the polycation. Molecular mass characteristics of polymers play essential role in physics and mechanical properties of the coatings. In this work, the properties of polydiallyldimethylammonium chloride (PDADMAC) coatings of various molecular weights are investigated and assumptions are made about the optimal molecular weight needed to create antibacterial compositions. To study the resistance to washing off and moisture saturation of the coatings, the gravimetric method was used, the adhesive properties of the coatings were studied by dynamometry. It has been established that an increase in molecular weight affects the wash-off resistance of coatings, but does not affect moisture absorption and adhesion mechanics of coatings. All samples of PDADMAC were demonstrated to exhibit the same antibacterial activity. Thus, when developing systems for creating antibacterial coatings, it must be taken into account that in order to create stable coatings. The requirement to use PDADMAC with a high degree of polymerization is necessary for control the desorption of coating during wash off-but not mandatory for the control of mechanical and antibacterial properties of the coating.

Hydrogel wound dressings hold great potential in eliminating bacteria and accelerating the healing process. However, it remains a challenge to fabricate hydrogel wound dressings that simultaneously exhibit excellent mechanical and photothermal antibacterial properties. Here we report the development of polydopamine-functionalized graphene oxide/calcium alginate/Polypyrrole cotton fabric-reinforced hydrogels (abbreviated as rGO@PDA/CA/PPy FHs) for tackling bacterial infections. The mechanical properties of hydrogels were greatly enhanced by cotton fabric reinforcement and an interpenetrating structure, while excellent broad-spectrum photothermal antibacterial properties based on the photothermal effect were obtained by incorporating PPy and rGO@PDA. Results indicated that rGO@PDA/CA/PPy FHs exhibited superior tensile strength in both the warp (289±62.1N) and weft directions (142±23.0N) similar to cotton fabric. By incorporating PPy and rGO@PDA, the swelling ratio was significantly decreased from 673.5% to 236.6%, while photothermal conversion performance was significantly enhanced with a temperature elevated to 45.0 ℃. Due to the synergistic photothermal properties of rGO@PDA and PPy, rGO@PDA/CA/PPy FHs exhibited excellent bacteria-eliminating efficiency for S. aureus (0.57%) and E. coli (3.58%) after exposure to NIR for 20 min. We believe that the design of fabric-reinforced hydrogels could serve as a guideline for developing hydrogel wound dressings with improved mechanical properties and broad-spectrum photothermal antibacterial properties for infected wound treatment.

Biomedical implants are the need of this era due to the increase in number of accidents and follow-up surgeries. Different types of bone diseases such as osteoarthritis, osteomalacia, bone cancer, etc. are increasing globally. Mesoporous bioactive glass nanoparticles (MBGNs) are used in biomedical devices due to their osteointegration and bioactive properties. In this study, silver (Ag) and strontium (Sr) doped mesoporous bioactive glass nanoparticles (Ag-Sr MBGNs) were prepared by a modified Stöber process. In this method, Ag+ & Sr2+ were co-substituted in pure MBGNs to harvest the antibacterial properties of Ag ions, as well as pro-osteogenic potential of Sr2 ions. The effect of the two ion concentration on morphology, surface charge, composition, antibacterial ability, and in-vitro bioactivity was studied. Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed the doping of Sr and Ag in MBGNs. SEM and EDX analysis confirmed the spherical morphology and typical composition of MBGNs, respectively. The Ag-Sr MBGNs showed a strong antibacterial effect against Staphylococcus carnosus and Escherichia coli bacteria determined via turbidity and disc diffusion method. Moreover, the synthesized Ag-Sr MBGNs develop apatite-like crystals upon immersion in simulated body fluid (SBF), which suggested that the addition of Sr improved in-vitro bioactivity. The Ag-Sr MBGNs synthesize in this study can be used for the preparation of scaffolds or as a filler material in the composite coatings for bone tissue engineering.

Emergence of more virulent forms of human pathogenic bacteria with multi drug resistance is a serious global issue and requires alternative control strategies. The current study was focused to investigate the antibacterial and antibiofilm potential of ferulic acid grafted chitosan (CFA) against Listeria monocytogenes (LM), Pseudomonas aeruginosa (PA), and Staphylococcus aureus (SA). The present result showed that CFA at 64 µg/mL concentration exhibit bactericidal action against LM and SA (>4 log reduction) and bacteriostatic action against PA (<2 log CFU) within 24 h of incubation. Further studies based on propidium iodide uptake assay, measurement of material released from the cell, and electron microscopic analysis revealed that the bactericidal action of CFA was due to the altered membrane integrity and permeability. CFA dose-dependently inhibited biofilm formation (52-89% range), its metabolic activity (30.8-75.1% range) and eradicated mature biofilms, and reduced viability (71-82% range) of the test bacteria. Also, the swarming motility of LM was differentially affected at sub-MIC concentration of CFA. In the present study, the ability of CFA to kill and alter the virulence production in human pathogenic bacteria will insight a new scope for the application of these biomaterials in healthcare to effectively treat bacterial infections.

Developing nanomaterials with the capacity to restrict the growth of bacteria and fungus is of current interest. In this study, nanocomposites of poly(2-hydroxyethyl methacrylate) (PHEMA) and carbon nanotubes (CNTs) functionalized with primary amine, hydroxyl, and carboxyl groups were prepared, and characterized. An analysis by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy showed that PHEMA chains were grafted to the functionalized CNTs. The morphology of the prepared nanocomposites studied by field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM) shows significant changes with respect to the observed for pure PHEMA. The thermal behavior of the nanocomposites studied by differential scanning calorimetry (DSC) revels that the functionalized CNTs affects strongly the mobility of the PHEMA chains. Tests carried out by thermogravimetric analysis (TGA) were used to calculate the degree of grafting of the PHEMA chains. The ability of prepared nanocomposites to inhibit the growth of the fungus Candida albicans, and the bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli was evaluated. A moderated antifungal and antibacterial capacity of the prepared nanocomposites was determined.

In this work, we designed and fabricated a multifunctional nanocomposite system which consists of chitosan, raspberry-like silver nanoparticles and graphene oxide. Room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environment-friendly method for introducing silver nanoparticles into the composite system. By loading different drugs onto the polymer matrix and/or graphene oxide, our composite can achieve a pH controlled dual drug release with release profile specific to the drugs used. In addition to its strong antibacterial ability against E. coli and S. aureus, our composite also demonstrates excellent photothermal conversion effect under irradiation of near infrared lasers. These unique functionalities point to it’s the potential of nanocomposite system in multiple applications areas such as multimodal therapeutics in healthcare, water treatment, and anti-microbial, etc.

The North African E. pinnata is not known as a traditional medicinal plant but modern research has revealed its extracts richness in anti-oxidants and components of medicinal value. Despite its wide distribution and medicinal value, the species remains taxonomically and phytochemically un-derstudied, especially in Algeria. Here we compare three ecotypes of E. pinnata from the humid, sub-humid and semi-arid areas. The comparison was carried out using classical techniques of multivariate plant morphology, pollen grains size and shape, chromosome numbers, pollen fer-tility, anti-oxidant and antibacterial activities. Significant differences were revealed for all criteria except pollen fertility and antibacterial activity. The semi-arid ecotype showed to be a remote group in relation to the two others except for pollen size where the remote group was the sub-humid ecotype. Pollen size appeared positively correlated with karyotype length. The results (mg GAE/g EXT) of the antioxidant activity tests of the “humid”, “sub-humid” and the “semi-arid” plant groups are as follows, respectively; TPC: 50.79±0.51, 52.04±1.05 and 56.89±0.46; DPPH: 71.18±2.24, 86.39±3.02 and 95.67±2.02; RP: 11.09±1.24, 17.21±0.75 and 25.88±0.26. The inhibition area diameter in the antibacterial activity test varied from 9.25±1.06 mm (Semi-arid plants vs Pseudo-monas aeruginosa) to 12.00±1.41 mm (Sub-humid plants vs Escherichia coli).

Background: Staphylococcus aureus is a ubiquitous organism that normally colonizes the human body and causes food poisoning. Aim: This study aimed to determine the rate of nasal carriage of S. aureus among food handlers in Sana’a restaurants in, Yemen and performed an antibacterial susceptibility test. Methods: This cross-sectional study was carried out among healthy food handlers from November 2022 to March 2023. Approximately 420 nasal swabs were collected and S. aureus was isolated and identified according to standard bacteriological procedures. Moreover, the antibacterial susceptibility pattern was determined using the disc diffusion method. Additionally, the required data were obtained by using the pretested questionnaire. Results: Of 420 nasal swabs, 78 (18.6%) food handlers were S. aureus nasal carriers. The prevalence rate of S. aureus was significantly higher among subjects aged >30 years (23.1%), males (18.8%), and uneducated subjects (25%). Additionally, a higher rate of S. aureus nasal carriers was observed among food handlers who worked as cooks (19.4%), had less than 2 years of experience (20.5%), and had low hygiene (29%). The S. aureus isolates were sensitive to ciprofloxacin (71.8%), vancomycin (76.9%), and amoxicillin-clavulanic acid (61%). Conversely, the isolated S. aureus was resistant to oxacillin (69.2%) and methicillin (66.7%). Conclusion: These data stress that food handlers with a high S. aureus nasal carrier rate may pose significant risks to consumers. Therefore, creating restaurant policies and rules is necessary to provide safe and healthy food to consumers.

The emergence of drug resistant pathogenic bacteria is increasingly challenging conventional antibiotics. Plant derived flavonoids are considered as potential alternatives to antibiotics due to their antimicrobial properties. However, the mechanisms by which flavonoids modulate pathogenic microorganisms’ growth are not fully understood. In our previous studies we found that Rutin, a kind of flavonoids showed inhibition against Klebsiella pneumoniae strains. In order to better understand its inhibitory mechanism on strain growth, we used both Rutin and Luteolin as treatments to incubate K. pneumoniae ATCC700603 strain. After incubation for 4 hours, the homogenous and differential effects of two different flavonoids on the growth of K. pneumoniae were evaluated. The integrated metabolomic and transcriptomic analysis was performed. The expression levels of 5,483 genes and the contents of 882 metabolites were measured. The differentially expressed genes (DEGs) and metabolites (DEMs) were screened and analyzed. The correlation between DEGs and DEMs were also studied. Our results showed that Rutin could inhibit the strain growth by changing metabolic pathways and ABC transporters pathways. Our study also revealed FU841_RS17580 and FU841_RS19145 as functional genes that played vital roles in the strain growth.

Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe₃O₄). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe₃O₄ nanoparticles (Fe₃O₄ NP’s) was calculated by Williamson-Hall method. The photocatalytic properties of the Fe₃O₄ NP´s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally the antibacterial effect of the Fe3O4 NP´s were evaluated mediated the Kirby-Bauer method against E. coli and S. aureus bacteria. This route offers a green alternative to obtain Fe3O4 NP´s with remarkable magnetic, photocatalytic and antibacterial properties.

This article discusses the fabrication of pullulan/polyvinyl alcohol (PVA) and PVA blends as carrier polymers for drug delivery. This study utilized coaxial electrospinning to encapsulate doxorubicin (DOX), a common anticancer drug, within nanofibers, which helped mitigate the adverse effects of DOX on normal cells. The study also demonstrated that the coaxial electrospinning technique using PVA/pullulan cores was effective in inhibiting the attachment and proliferation of HeLa cells, a type of cervical cancer cell. The use of pullulan/PVA and PVA blends as carrier polymers in conjunction with coaxial electrospinning could provide a safe and effective drug delivery system for the treatment of cervical and other solid malignancies. The study concluded that nanofibers showed promising results in inhibiting the growth of HeLa cells, indicating their potential as safe and effective drug delivery systems for treating cervical cancer and other solid malignant tumors.

Objective: The aim of the study was to characterize varieties of Moringa alfileria honey (unfloral and polyfloral) from Saudi Arabia based on antibacterial, antioxidant activities, physicochemical, melissopalynological analysis, total phenolic and flavonoid contents. Material and Methods: The fresh 376 honey samples (3 kg of each) were kindly provided by Alnahal aljwal Company, 2021 flowering season. The honey samples collected in sterile universal glass containers and kept at 2– 8°C until tested. Antibacterial, antioxidant activities and physiochemical analysis were done. Determination of sediment content, total grains, moisture content, water-soluble solids, acidity, electrical conductivity, total sugars content, inverted sugars, glucose (g/100 g), fructose (g/100 g), total glucose + fructose, fructose/ glucose ratio, sucrose (g/100 g), diastase enzyme activity and HMF were calculated. As well as total phenolic and flavonoid contents Results: Antibacterial activity and physiochemical analysis of honey samples w varied. All parameters studied were significantly different (P < 0.05) among all honey varieties. The results of the physiochemical analysis were compared with Saudi National Standard, Codex standard, as well as published data in the literature. Conclusion: It was obvious that the honey quality was varied based on the botanical origins

Nisin, an antibacterial compound produced by Lactococcus lactis strains, has been approved by the US Food and Drug Administration to be used as a safe food additive to control the growth of undesirable pathogenic bacteria. Nisin is commonly described as a pH-dependent primary metabolite, since its production depends on growth and culture pH evolution. However, the relationship between bacteriocin synthesis and the consumption of the limiting nutrient has not been described until now. Therefore, this study aimed to develop a competitive four-dimensional Lotka Volterra-like equation to describe the relationships between culture pH, limiting nutrient (total nitrogen: TN) consumption and production of biomass (X) and nisin (BT) in four series of batch fermentation with L. lactis CECT 539 in diluted whey (DW)-based media. The developed four-dimensional LV-like equation (with a unique set of parameters) could not be used to describe all cultures belonging to each fermentation series. However, the four-dimensional LV-like equation described accurately each individual culture, providing a good description of the relationships between pH, TN, X and BT, higher values for R2 and F-ratios, lower values (&lt; 10%) for the mean relative percentage deviation modulus, with bias and accuracy factor values approximately equal to one.

Researchers are increasingly focusing on green synthesis methods for silver nanoparticles due to their cost-effectiveness and reduced environmental impact. In this study, we utilized an edible bird's nest (EBN), a valuable economic resource, as the primary material for synthesizing silver nanoparticles using only water as the solvent. Metabolite profiling of the EBN extract was conducted using LC-QTOF-MS in positive mode (ESI+), revealing the presence of lipids, glycosides, peptides, polysaccharides, and disaccharides. Upon the addition of silver nitrate to the aqueous EBN extract, noticeable color changes from transparent to brown indicated the successful formation of AgNPs. Subsequent characterization of these silver nanoparticles involved UV-Visible spectroscopy, which revealed an absorption peak at 421 nm. Further characterization was carried out using Field Effect Scanning Electron Microscopy (FESEM), Attenuated Total Reflectance-Fourier Infrared (ATR-FTIR) spectroscopy, and Energy Dispersive X-Ray (EDX) analysis. The involvement of phenolic agents, proteins, and amino acids in reducing the silver particles was confirmed. The synthesized nanoparticles exhibited a crystalline nature, a spherical shape, and a particle size ranging from 10 to 20 nm. The presence of elemental silver was confirmed by a strong, intense peak around 3 keV in the EDX spectrum. To assess their potential, the antibacterial properties of the silver nanoparticles against Escherichia coli and Staphylococcus aureus were evaluated using the agar diffusion method.

Fifteen new diterpenoids, namely xishaklyanes A-O (1-15), along with three known related ones (16-18), were isolated from the soft coral Klyxum molle collected from Xisha Islands, South China Sea. The stereochemistry of the new compounds were elucidated by a combination of detailed spectroscopic analyses, chemical syntheses, quantum chemical calculations and comparison with the reported data. The absolute configuration of compound 18 was established by the modified Mosher's method for the first time. In bioassay, some of these compounds exhibited considerable antibacterial activities on fish pathogenic bacteria, and compound 4 showed the most effective activity with MIC of 0.225 g/mL against Lactococcus garvieae.

Rapid developing antimicrobial resistance due to broad antibiotic utilisation in healthcare and food industries and the non-availability of novel antibiotics represents one of the most critical public health issues worldwide. The current advances in nanotechnology allow new materials to address drug-resistant bacterial infections in specific, focused and biologically safe ways. The unique physicochemical properties, biocompatibility, and wide range of adaptability of nanomaterials that exhibit photothermal capability can be employed to develop the next generation of photothermally induced controllable hyperthermia as antibacterial nanoplatforms. Here, we review the current state-of-the-art in different functional classes of photothermal antibacterial nanomaterials and the strategies to optimise antimicrobial efficiency. The recent achievements and trends in developing photothermally active nanostructures, including plasmonic metals, semiconductor, carbon-based, and organic photothermal polymers, and antibacterial mechanisms of action, including anti-multidrug resistant bacteria and biofilms removal, will be discussed. Insights into mechanisms of the photothermal effect and various factors influencing photothermal antimicrobial performance, emphasising the structure–performance relationship, are discussed. We will examine the photothermal agents’ functionalisation for specific bacteria, effects of near-infrared light irradiation spectrum, or active photothermal materials for multimodal synergistic-based therapies to minimise side effects and maintain low cost. Most relevant applications are presented, such as anti-biofilm formation, biofilm penetration or ablation, and nanomaterial-based infected wound therapy. Practical antibacterial applications employing the photothermal antimicrobial agents, alone or in synergistic combination with other nanomaterials, are considered. Existing challenges and limitations in photothermal antimicrobial therapy and future perspectives are presented from the structure, function, safety, and clinical potential points of view.

Antibiotics have become a widely used drug classes worldwide. Its indiscriminate use in the clini-cal-hospital environment ended up causing antibiotic-resistance genes. Pharmaceutical technology is an essential ally for new formulation development in the antibacterial field. Cyclodextrins (CDs) are ap-proaches that can potentially improve the effectiveness of antibacterial drugs. Thus, this study aimed to review experimental models using CDs as inclusion complexes to improve antibacterial drugs’ physi-cochemical characteristics and biological activities. The review was carried out using the three online journals database PubMed, Scopus, and Embase, limited to Medical Subjects Headings Index. The search protocol was registered in the Open Science Framework database. The following terms and their com-binations were used: cyclodextrins and antibacterial agents in title or abstract, and a total of 1580 studies were identified in a period up to October 2022. Finally, 27 articles were selected for discussion in this review. The biological results reveal that the antibacterial effect of the compounds, complexed with CDs, was extensively improved when compared to the free drugs. CDs can improve the therapeutic effects of antibiotics, already existing on the market, natural products, and synthetic molecules. Therefore, these inclusion complexes using CDs increase the new pharmaceutical products development for clinical ap-plication.

Organically-coated nanomaterials are intensively studied and find numerous applications in a wide range of areas ranging from optics to biomedicine. One of the recent trends in material science is the application of bio-mimetic polydopamine coatings that can be produced on a variety of substrates in a cost-efficient way under mild conditions. Such coatings not only modify the biocompatibility of the material but also add functional amino groups to the surface that can be further modified by classic conjugation techniques. Here we show an alternative strategy of substrates modification using not dopamine but dopamine conjugates. Compared to the classic scheme the proposed strategy allows for separation of the "organic" and "colloidal" stages and simplifies identification and purification steps. Modification with pre-modified dopamine allowed to achieve high active components loading up to 10.5% wt. A series of organo-inorganic hybrids were synthesized and their bioactivity was analyzed.

Peri-implantitis occurs at a significant rate, which is the leading cause of implant failure. The main reason for this unwanted complication is bacterial invasion and biofilm formation. To reduce the incidence of peri-implantitis, we constructed a carboxymethyl dextran (CMD) based nanomicelles antibacterial coating on microarc-oxidized titanium (MAO-Ti) surface. After cross-linking, the drug-loaded nanomicelles were spherical with a particle size of 130nm and uniformly dispersed. Zeta potential was negative, and the absolute value was greater than 10 mV, effectively avoiding micelles aggregation. It was observed by dynamic light scattering (DLS) that the stability of nanomicelles was significantly improved after cross-linking. The hemolysis rate of micelles was less than 5%, and the overall survival rate of human umbilical vein endothelial cells was more than 90%. After being coated on MAO-Ti surface, the cumulative drug release rate of drug-loaded nanomicelles reached 86.6% after 360 hours. Fluorescence staining of immobilized bacteria showed more dead bacteria on the coating surface, and the number of live bacteria was significantly reduced. It was concluded that dextran-based nanomicelles, which showed long-term drug release properties and excellent biocompatibility, are potential drug carriers for fabricating antibacterial coating on titanium surfaces.

An efficient procedure for the synthesis of polyhydroxyl aromatic compounds (phloroglucide analogs) is described. In this procedure a reaction was done between different 4-substituted phenols and 2,6-bis(hydroxymethy) phenols. The reactions proceed in the presence of catalytic amount of silica gel supported boric tri-sulfuric anhydride (SiO2-BTSA) in excellent yields. 16 compounds were synthesized (I1-I16). Chemical structures of all compounds were confirmed by spectroscopic methods. We optimized the chemical reactions in the presence of different acidic catalysts, different solvents and also different temperatures. Catalytic amounts of SiO2-BTSA in dichloroethane (DCE) was the best conditions. Some of the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated by broth micro dilution method as recommended by CLSI. Some of the tested compounds show good in vitro biological properties.

Silver nanoparticles (AgNPs) have been demonstrated to restrain bacterial growth while maintaining the minimal risk in development of bacterial resistance and human cell toxicity that conventional silver compounds exhibit. Several physical and chemical methods have been reported to synthesize AgNPs. However, these methods are expensive and involve heavy chemical reduction agents. An alternative approach to produce AgNPs in a cost-effective and environmentally friendly way employs a biological pathway using various plant extracts to reduce metal ions. The size control issue and the stability of nanoparticles remain some of the latest challenges in such methods. In this study, we used two different concentrations of fresh leaf extract of the plant Arbutus Unedo (LEA) as a reducing and stabilizing agent to produce two size variations of AgNPs. UV-Vis spectroscopy, Dynamic Light Scattering, Transmission Electron Microscopy and zeta potential were applied for the characterization of AgNPs. Both AgNP variations were evaluated for their antibacterial efficacy against the gram-negative species Escherichia coli and Pseudomonas aeruginosa, as well as the gram-positive species Bacillus subtilis and Staphylococcus epidermidis. Although significant differences have been achieved in the nanoparticles’ size by varying the plant extract concentration during synthesis, the antibacterial effect was almost similar.

Essential oils (EO) are a great antimicrobial resource against bacterial resistance in public health. Math models are useful describing the growth, survival, and inactivation of microorganisms against antimicrobials. We evaluated the antimicrobial activity of M. armillaris EO obtained from plants placed in the province of Buenos Aires (Argentina) against Staphylococcus aureus. Minimum Inhibitory and Bactericidal Concentrations were close and decreased slightly acidifying the medium from pH 7.4 to 6.5 and 5.0. This result was also evidenced by applying a sigmoid model, where the time and EO concentration necessaries to achieve 50% of the maximum effect decreased when medium was acidified. Moreover, at pH 7.4, applying the Gompertz model, we found that subinhibitory concentrations of EO decreased the growth rate and the maximum population density, and increased the latency period respect to the control. Additionally, we established physicochemical parameters for quality control and standardization of M. armillaris EO. Mathematical modelling allowed us to estimate key parameters in the behavior of S. aureus and Melaleuca armillaris EO at different pHs. This is interesting in situations where the pH changes are relevant, such as the control of intracellular infections in public health or the development of preservatives for food industry.

White spot lesions (WSLs), a side effect of orthodontic treatment, can result in reversible and unaesthetic results. Graphene oxide (GO) with a bioactive glass (BAG) mixture(BAG@GO) was added to Low Viscosity Transbond XT(LV) in a ratio of 1, 3, 5%. The composite’s characterization and its physical and biological properties were verified with scanning electron microscopy(SEM) and X-ray diffraction(XRD); its microhardness, shear bond stress (SBS), cell viability, and adhesive remnant index (ARI) were also assessed. Efficiency in reducing WSL was evaluated using antibacterial activity of S. mutans. Anti-demineralization was analyzed using a cycle of the acid-base solution. Adhesives with 3 or 5 wt.% of BAG@GO showed significant increase in microhardness compared with LV. The sample and LV groups showed no significant differences in SBS or ARI. The cell viability test confirmed that none of the sample groups showed higher toxicity compared to the LV group. Antibacterial activity was higher in the 48-hour group than in the 24-hour group; the 48-hour test showed that BAG@GO had a high antibacterial effect, which was more pronounced in 5 wt.% of BAG@GO. Anti-demineralization effect was higher in the BAG@GO-group than in the LV-group; the higher the BAG@GO concentration, the higher the anti-demineralization effect.

Alzheimer’s disease (AD) is a chronic neurodegenerative disease associated with the overproduction and accumulation of amyloid-β peptide and hyperphosphorylation of tau proteins in the brain. Despite extensive research on the amyloid-based mechanism of AD pathogenesis, the underlying cause of AD remains poorly understood. No disease-modifying therapies currently exist, and numerous clinical trials have failed to demonstrate any benefits. The recent discovery that the amyloid-β peptide has antimicrobial activities supports the possibility of an infectious aetiology of AD and suggests that amyloid-β plaque formation might be induced by infection. AD patients have a weakened blood-brain barrier and immune system and are thus at elevated risk of microbial infections. Such infections can cause chronic neuroinflammation, production of the antimicrobial amyloid-β peptide, and neurodegeneration. Various pathogens, including viruses, bacteria, fungi, and parasites have been associated with AD. Most research in this area has focused on individual pathogens, with herpesviruses and periodontal bacteria being most frequently implicated. The purpose of this review is to highlight the potential role of multi-pathogen infections in AD. Recognition of the potential coexistence of multiple pathogens and biofilms in AD's aetiology may stimulate the development of novel approaches to its diagnosis and treatment. Multiple diagnostic tests could be applied simultaneously to detect major pathogens, followed by anti-microbial treatment using antiviral, antibacterial, antifungal, and anti-biofilm agents.

Bioprospecting native Australian plants offers potential discovery of latent and novel bioactive compounds. Promising cytotoxic and antibacterial activity of methanolic extracts of Pittosporum angustifolium and Terminalia ferdinandiana led to further fractionation and isolation using our laboratory’s bioassay guided fractionation protocol. Hence, the aim of this study was to further evaluate the bioactivity of the fractions and subfractions and characterize bioactive compounds using liquid chromatography mass spectroscopy (LC-MS/MS) and gas chromatography MS (GC-MS). Compounds tentatively identified in P. angustifolium Fraction 1 using LC-ESI-QTOF-MS/MS were chlorogenic acid and/or neochlorogenic acid, bergapten, berberine, 8’-epitanegool and rosmarinic acid. GC-MS analysis data showed the presence of around 100 compounds, mainly comprising of carboxylic acids, sugars, sugar alcohols, amino acids, and monoalkylglycerols. Furthermore, the fractions obtained from T. ferdinandiana flesh extracts showed no cytotoxicity, except against HT29 cell lines, and only Fraction 2 exhibited some antibacterial activity. The reduced bioactivity observed in the T. ferdinandiana fractions could be attributed to the potential loss of synergy as compounds become separated within the fractions. As a result, further fractionation, and separation of compounds in these samples were not pursued. However, additional dose-dependent studies are warranted to validate the bioactivity of T. ferdinandiana flesh fractions, particularly since this is an understudied species. Moreover, LC-MS/GC-MS studies confirm the presence of bioactive compounds in P. angustifolium Fraction 1/subfractions which helps to explain the significant acute anti-cancer activity of this plant. The screening process designed in this study has the potential to pave the way for developing scientifically validated phytochemical/bioactivity information on ethnomedicinal plants, thereby facilitating further bioprospecting efforts, and supporting the discovery of novel drugs in modern medicine.

This study aimed to evaluate the antioxidant activities (AA) of lyophilized rosemary extract and lyophilized sage extract and their effects on the oxidative stability of poultry pátê. For this purpose, four poultry pátê formulations with rosemary, sage, sodium erythorbate, and a control (without antioxidants) were produced. The rosemary and sage were characterized according to total phenolic compounds (TPC), and AA by several methods. The poultry pátês stored at 4°C were evaluated by the lipid oxidation. High concentrations of TPC were detected in rosemary extract and sage extract (46.48 and 41.61 mg GAE/g: Gallic acid equivalent respectively). The AA of rosemary and sage extracts by free radical-scavenging were 4745.72 and 2462.82 µmol Trolox/g, respectively. The high concentration of catechin, rutin, myricetin and p-coumaric acids in these extracts may be responsible for the strong inhibitory action against food pathogens. Besides these compounds can be responsible for the best performance in inhibiting lipid oxidation in poultry pátês during the storage. This study suggests that rosemary and sage extracts may be used as a natural antioxidant in meat products.

Phenothiazine derivatives are widely studied in various fields such as biology, chemistry, and medicine research because of their pharmaceutical effects. The first reagent that was used suc-cessfully in the treatment of psychosis was a phenthiazine derivative, chlorpromazine. Apart from their activity in neurons, chlorpromazine have also been reported to display anticancer and antibacterial properties. In these studies, we present the synthesis and research on the activ-ity against A549, MDA, MiaPaCa, PC3 and HCT116 cancer cell lines and against S. aureus, S. epi-dermidis, E. coli and P. aeruginosa bacterial strains a series of new tetracyclic chlorpromazine ana-logues containing a quinoline scafford in their structure instead of the benzene ring and various substituents at the thiazine nitrogen. The structure of these novel molecules has been deter-mined by 1H NMR, 13C NMR and HRMS spectral techniques. The seven most active of the twen-ty-four new chlorpromazine analogues tested were selected for study of the mechanism of cyto-toxic action. Their ability to induce apoptosis or necrosis in cancer cells was assessed by flow cytometry analysis. The results obtained confirmed the proapoptotic activity of selected com-pounds, especially in terms of inducing late apoptosis or necrosis in cancer cell lines A549, Mi-aPaCa-2 and HCT-116. Furthermore, studies on the induction of cell cycle arrest suggest that the new chlorpromazine analogues exert antiproliferative effects by inducing cell cycle arrest in the S phase and, consequently, apoptosis.

Application of toxic antibacterial agents is considered necessary to control prevalent fresh water microorganisms in evaporative cooling water systems, but these agents can adversely affect the environment and human health. Alternatively, natural antibacterial water chemistry has been applied in industrial cooling water systems for over 10 years with excellent results. The tower water chemistry method concentrates natural salts in highly-softened water to produce elevated pH and dissolved solids, with low calcium and magnesium. This practice conserves water while generating only a small volume of non-toxic natural salt concentrate for cost efficient separation and disposal if required. This review presents a novel perspective of natural antimicrobial chemistry for inhibiting parasitic microbiome functional relationships within the bio-triad of Legionella outbreaks, "Trojan Protozoans" and biofilms. The review further examines practical application and function of polyvalent metal ions in the inhibition of biofilms. Reducing global dependence on toxic antibacterial agents discharged to the environment is an emerging concern due to their impact on the natural microbiome, plants, animals and humans. Discharge of antibacterial agents also contributes to development of pathogen resistance. Use of natural antibacterial chemistry can play a key role in managing the cooling water environment in a more ecologically sustainable manner.

Ocular pathologies present significant challenges in achieving effective therapeutic re-sults due to various anatomical and physiological barriers. Natural products, such as flavonoids, alone or in association with allopathic drugs, present many therapeutical actions, including anti-cancer, anti-inflammatory, and antibacterial action. However, their clinical employment is chal-lenging for scientists due to their low water solubility. In this study, we designed a liquid formu-lation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were de-termined by employing the SupraFit software on the Uv-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it con-firmed the predominant formation of a stable complex (Kc, 9660 M−1) in a 1:1 molar ratio, with high water solubility of 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), per-mitting the dissolution of the solid complex within 30 min. NMR studies revealed the involve-ment of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecu-lar modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains demonstrating a sig-nificant activity of the formulation to the free components.

Nanofibers are one of the most attractive materials that can modify functionalities for developing new kinds of specific applications, mainly used as a biomedical material. Herein, we designed and prepared the antibacterial nonwoven fiber mats of PLA and PLA composited with Ag nanoparticles by electrospinning. The effects of varying filler contents on their chemical, surface morphology, thermal, water absorbency, and antibacterial properties were investigated using FTIR, SEM/EDS, DSC, swelling ratio, and qualitative and quantitative antibacterial tests. FTIR and EDS spectra indicated that Ag nanoparticles were incorporated in the PLA without chemical bonding. SEM revealed that the average diameter of the PLA nanofibers containing the Ag nanoparticles was more significant than those without those particles. Besides, fiber diameters are proportionally the amount of Ag nanoparticle contents. DSC indicated that the Ag nanoparticles can be incorporated within the PLA-matrix without strongly affecting their thermal properties. Moreover, the crystallinity of the composite nonwoven fiber mats was higher than those of fiber mats in the neat PLA. Accordingly, the antibacterial activities revealed that all the composite nanofiber mats exhibited excellent against S. aureus and E. coli bacterial strains. In addition, in the cell toxicity study, all produced hybrids nonwoven fiber mats induced a reduction in cell viability for the L929 fibroblast cells. Our results suggest that the designed and prepared nonwoven fiber mats may have good potential for use in the biomedical field, particularly in wound dressing applications

Various 4-aminotetrahydropyridinylidene salts were treated with aldehydes in alkaline medium. Their conversion to 5-substituted -hydroxyketones in a one-step reaction succeeded only with an aliphatic aldehyde. Instead, aromatic aldehydes gave 5-substituted -aminoketones or a single -diketone. The new compounds were characterized by spectroscopic methods and a single crystal structure analysis. Some of them showed anticancer and antibacterial properties.

Present study reports the green synthesis of pectin fabricated silver-based nanocomposite (Pectin-AgNPs) with Carpesiumnepalense leaves extract and evaluated their bactericidal kinetics, in-vivo hepatoprotective and cytotoxic potentials with their possible mechanisms. GC/MS and LC/MS analysis indicated the presence of different new phytochemicals constituents in the plant extract. The physicochemical characterization of Pectin-AgNPs by UV/Vis, SEM, DLS, FTIR and EDX techniques showed the spherical and uniform size range synthesis of nanocomposite i.e. 50-110 nm. The highly significant (P<0.005) antibacterial activity was found against all tested four bacterial strains with the ZIs of 24.8 to 27.2 mm. Significant damage in bacterial cell membrane was also observed in AFM study after treated with Pectin-AgNPs. At the doses of 0.05 mg/kg, nanocomposite showed highly significant (P<0.005)hepatoprotective activity in biochemical and histopathology analysis as compared to CCL4 administered control group. The ameliorative effects of Pectin-AgNPs were observed in PCR analysis on both GAPDH and PPARs genes expression and its potential to restore gene alterations caused by CCl4 intoxication.Pectin-AgNPs produced cytotoxic activity against HeLa cell lines at higher doses with the LC50 of 223.7 µg/mL. The current findings demonstrate positive attributes of pectin fabricated AgNPs as a promising antibacterial, hepatoprotective and cytotoxic agent.

New generation antibiotics are needed to combat the development of resistance to antimicrobials. One of the most promising new classes of antibiotics is cannabidiol (CBD). It is a non-toxic and low-resistance chemical that can be used to treat bacterial infections. The antibacterial activity of Cannabis sativa L. byproducts, specifically CBD, has been of growing interest in the field of novel therapeutics. As research continues to define and characterize the antibacterial activity that CBD possesses against a wide variety of bacterial species it is important to examine potential interaction between CBD and common therapeutics such as broad-spectrum antibiotics. Here, we show that CBD-antibiotic co-therapy can effectively fight S. typhimurium via membrane integrity disruption. This research serves to examine the potential synergy between CBD and three broad-spectrum antibiotics for potential antibiotic-CBD co-therapy. In this study, we reveal that Salmonella typhimurium (S. typhimurium) growth is inhibited at very low dosages of CBD-antibiotic. This interesting finding demonstrates that CBD and CBD-antibiotic co-therapies are viable novel alternatives to combating Salmonella typhimurium.

This review revisits clinical use of antibiotics for most common acute oro-dental conditions; we aim to provide evidence governing antibiotics use when access to oral healthcare is not available, as during the ongoing outbreak of the severe acute respiratory syndrome coronavirus 2. In this rapid review, articles were retrieved after conducting a search on PubMed and Google Scholar. Relevant publications were selected and analyzed. Most recent systematic reviews with/without meta-analyses and societal guidelines were selected. Data were extracted, grouped, and synthesized according to the respective subtopic analysis. There were evidence supporting the use of antibiotics in common oro-dental conditions as temporary measure when immediate care is not accessible, such as in case of localized oral swellings as well as to prevent post-extraction complications. No sufficient evidence could be found in support of antibiotic use for pain resulting from pulpal origin. Consequently, antibiotic use may be justified to defer treatment temporarily or reduce risk of complications in case of localized infection and tooth extraction, when no access to immediate dental care is possible.

The aim of performed studies was to fabricate an antibacterial and degradable scaffold that may be used in the field of skin regeneration. To reach the degradation criterion the biocompatible polyurethane (PUR), obtained by using amorphous macrodiol α,ω-dihydroxy(ethylene-butylene adipate) macrodiol (PEBA), was used and processed with so-called “fast-degradable” polymer polylactide (PLA) (5 wt% or 10 wt%). To meet the antibacterial requirement obtained hybrid PUR-PLA scaffolds (HPPS) were modified with ciprofloxacin (Cipro) (2 wt% or 5 wt%), the fluoroquinolone antibiotic inhibiting growth of bacteria such as Pseudomonas aeruginosa, Escherichia Coli and Staphylococcus aureus, which are main cause of wound infections. Obtained unmodified and Cipro-modified HPPS were studied towards their chemical composition to detect presence or absence of characteristic functional groups of PUR, PLA and Cipro, and as well to indicate the participation of hydrogen bonds in the HPPS structure in dependence on PLA addition and ciprofloxacin modification. Mechanical properties were studied to determine the possible application of HPPS as a skin tissue scaffold. Scanning electron microscopy (SEM) was used to study morphology of unmodified and Cipro-modified HPPS and to performed elementary analysis by using energy-dispersive x-ray spectroscopy (EDX) of obtained materials. Finally, the microbiological tests were performed to indicate the antibacterial effect of Cipro-modified HPPS on S.aureus growth. Performed studies showed that Cipro-modified HPPS, obtained by using 5 % of PLA, possess suitable mechanical characteristic, morphology, degradation rate and demanded antimicrobial properties to be further developed as a potential scaffolds for skin tissue engineering.

The highly dangerous trend of escalating bacterial resistance to modern antibiotics has evolved in recent decades, with increasingly more drug-resistant strains of pathogens emerging and spreading each year. This poses a threat to not only public health, but also to entire mankind. Marine bioresources, considered as a promising alternative to traditional antibiotics and a valuable source of biologically active compounds with high pharmacological potential, now attract increasing attention of researchers. Modern biotechnology combines the genetic engineering methods and the unusual biosynthetic pathways utilized by marine microorganisms to produce natural antibiotics. The goal of this review is to summarize the latest trends in searching for new natural antimicrobial agents based on secondary metabolites of marine bacteria. The targeted control of biosynthesis mechanisms using the metabolic engineering methods in order to create hybrid peptide synthetases or to obtain hybrid peptides by disrupting the target gene of nonribosomal synthesis becomes a noteworthy trend in modern biotechnology. This pathway is not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the exocrine activity of pathogenic bacteria and, consequently, their viability.

Sol-gel route represents a valuable technique to obtain functional materials, in which organic and inorganic members are closely connected. Herein four hybrid materials, containing caffeic acid entrapped in a silica matrix at 5, 10, 15 and 20 wt%, were synthesized and characterized through FT-IR and UV-Vis spectroscopy. FT-IR analysis was also performed to evaluate the ability to induce the hydroxyapatite nucleation. Despite some structural changes occurred on the phenol molecular skeleton, hybrid materials showed scavenging properties vs DPPH and ABTS+ radicals, which was dependent on the tested dose and on the caffeic acid wt%. Finally, the SiO₂/caffeic acid materials have been proposed as valuable antibacterial agents against Escherichia coli and Enterococcus faecalis.

New antibiotics are unquestionably needed in the fight to the emergence and spread of multidrug-resistant bacteria. So far, antibiotics targeting bacterial central metabolism have been poorly investigated. By determining the minimal inhibitory concentration (MIC) of desmethylphosphinothricin (Glu-γ-PH), an analogue of glutamate with a phosphinic moiety re-placing the γ-carboxyl group, we previously showed its promising antibacterial activity on Escherichia coli. Herein we synthetized and determined the growth inhibition exerted on E. coli by an L-Leu dipeptide derivative of Glu-γ-PH (L-Leu-D,L-Glu-γ-PH). Furthermore, we compared the growth inhibition obtained with this dipeptide with that exerted by the free amino acid, i.e. Glu-γ-PH, and by their phosphonic and non-desmethylated analogues. All tested compounds were more effective when assayed in chemically defined minimal medium. The dipeptide L-Leu-D,L-Glu-γ-PH had a significantly improved antibacterial activity (2 μg/mL), at a concentra-tion between the non-desmethytaled (0.1 μg/mL) and the phosphonic (80 μg/mL) analogues. Also in Bacillus subtilis the dipeptide L-Leu-D,L-Glu-γ-PH displayed an activity comparable to that of the antibiotic amoxicillin. This work highlights the antibacterial relevance of the phosphinic pharmacophore and proposes new avenues to the development of novel antimicrobial drugs containing the phosphinic moiety.

There is a growing interest in a potential use of essential oils (EOs) as a possible alternative for chemical pesticides. The formulation between different EOs could maximize the single biological efficacy by synergic mechanism. The aim of the current study was to evaluate the biological activity of three prepared blended oil formulations (BOFs) derived from Origanum vulgare L. (oregano) and Salvia officinalis L. (sage) compared to each parent EO. The chemical composition of each single studied EO has been revealed using GC-MS analysis. The three BOFs have been prepared as following: i) 25% oregano EO + 25% sage EO (BOF-I); ii) 25% oregano EO + 5% sage EO (BOF-II); iii) 5% oregano EO + 25% sage EO (BOF-III). The antibacterial activity of the new BOFs has been evaluated against Bacillus megaterium, B. cereus and Xanthomonas campestris, whereas, the antifungal activity has been carried out against Botrytis cinerea, Penicillium italicum and Fusarium oxysporum. The possible phytotoxic effect of the new BOFs has been evaluated on Lepidium sativum (garden cress), Solanum lycopersicum (tomato) and Lactuca sativa (lettuce) following the seed germination and radicle elongation assay. GC-MS analysis revealed that the oregano EO composed mainly from thymol, p-cymene and carvacrol with 76.0, 5.7 and 3.2 %, respectively. Whereas, salvia EO, the GC-MS analysis showed that the relevant predominant constituents were trans-thujone and camphor with 37,9 and 13,9 %, respectively. Results demonstrated that the tested BOFs possess antimicrobial effect higher than each parent EO. In particular, BOF-II showed the highest effect against all tested bacteria. Regarding the antifungal activity, BOF-II showed the highest significant antifungal effect against all tested fungi. Results showed also that both BOF-I and BOF-III explicated a moderate effect against B. cereus and all tested fungi compared to single EOs. In addition, the three BOFs showed notable phytotoxic effect against all three tested plants, particularly BOF-I. Whereas, the single sage EO at 25% showed the lowest significant phototoxic effect indicating its possible using as natural herbicides.

Antimicrobial resistance (AMR) is a growing public health issue worldwide that affects the world economy. The concern associated with this issue increased during the COVID-19 pandemic. The misuse of antibiotics during the COVID-19 pandemic will have catastrophic implications for the control of AMR. In 2019, the coronavirus illness COVID-19 first appeared in China. COVID-19 infection is a surface-to-surface communicable disease. It is considered the most vital global health disaster of the century. It has rapidly spread around the world and is the greatest challenge for humankind. This chapter discusses the origin, symptoms, transmission, treatment, and recommendations of the COVID-19 disease.

In this study, a novel absorbable hemostatic agent was developed using carrageenan (CRG) as a natural polymer and cerium oxide nanoparticles (CeO2 NPs).  CRG-CeO2-0.5 and CRG-CeO2-1 composites were prepared by compositing CRG and CeO2 at a weight ratio of 200:1 and 100:1, respectively. Physio-chemical and structural properties of these compounds were studied and compared with pristine CRG. Upon incorporation of CeO2 nanoparticles into the CRG matrix, significant reductions in hydrogel degradation were observed. In addition, it was noted that CRG-CeO2 exhibited better antibacterial and hemostatic properties than CRG hydrogel without CeO2.The biocompatibility of the materials was tested using the NIH 3T3 cell line and all samples were found to be nontoxic. Particularly, CRG-CeO2-1 demonstrated superior hemostatic effects, biocompatibility, and a lower degradation rate since more CeO2 Nps were present in the CRG matrix. Therefore, CRG-CeO2-1 has the potential to be used as a hemostatic agent and wound dressing.

Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nano-biotechnology combined with green chemistry has great potential for the development of novel and necessary products that benefit human activities, while encourages the reduction of hazardous reagents for nanoparticle production. Green chemistry has an important role due to its contribution to unconventional synthesis methods of gold and silver nanoparticles from plant extracts, which have exhibited antimicrobial potential among other outstanding properties. Biodiversity-rich countries need to collect and convert knowledge from biological resources into processes, compounds, methods, and tools, which need to be achieved along with sustainable use and exploitation of biological diversity. Therefore, this review focuses on the importance of metal nanoparticles, the use of plant extract for their synthesis as well as other available methods, and the relevant antimicrobial activity that can be exploited in a sustainable model of agricultural management through a modern nanotechnological approach.

High rates of resistance to antibiotics are associated with healthcare-related infections, thus appealing for the urgent need for effective antimicrobials against these maladies. The present study aims to determine the chemical composition of essential oil (EO) from Clausena anisata leaves, and evaluate their antibacterial activity against selected nosocomial bacteria. Fresh leaves of Clausena anisata were subjected to a steam distillation using a Clevenger apparatus to afford the essential oil. The phytochemical composition of this oil was analyzed using gas chromatography-mass spectrometry (GC-MS). The essential oil was further tested against selected nosocomial bacteria, including Staphylococcus and Klebsiella species, among others, using a microdilution method. As a result, 0.77% of essential oil was extracted from fresh leaves of Clausena anisata. The GC-MS analysis revealed that the as-prepared essential oil contain E-anethole (70.77%), methyl isoeugenol (13.85%), estragole (4.10%), γ-terpinene (3.33%), myrcene (2.82%) and sabinene (0.77%), with E-anethole being the major constituent. Meanwhile, twenty two compounds were identified in the EO of Clausena anisata leaves through gas chromatography. Upon antibacterial test against selected nosocomial pathogens, the E-anethole-rich essential oil exhibited minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranging from 3.91 to 125 µg/mL and 7.81 to 125 µg/mL, respectively, indicative of a bactericidal orientation of the plant’s essential oil (MIC/MBC ratio: 4). This novel contribution highlights the scientific validation of the use of Clausena anisata leaves in the traditional treatment of various infectious diseases. However, toxicity and pharmacokinetic studies, mechanistic basis of the antibacterial action, and in vivo antibacterial experiments of the E-anethole-rich essential oil of Clausena anisata should be investigated to successfully use this plant in the treatment of infectious diseases.

Human serum albumin (HSA) is multifunctional protein, known to be a natural carrier for a number of endogenous and exogenous compounds, including drugs. Formulating anticancer drugs with HSA is a clinically validated approach to improve the pharmacological properties and provide targeted delivery (passive and active) of cytotoxic payload to the tumor (such as in Abraxane). A number of receptors facilitating HSA uptake from systemic circulation have been characterized. What is interesting, such uptake may differ depending on the nature and quantity of ligands bound to HSA. Based on this, one might like to modify the HSA in a way that its distribution is more favorable for certain therapeutic purposes, thus ensuring more efficient delivery of the therapeutic cargo to disease site. E.g. Levofloxacin (LV), broad spectrum antibiotic drug, could benefit from extended systemic exposure, and stronger interaction with plasma proteins could be useful for this purpose. We have engrafted monomeric or polymeric CDs on the surface of HSA molecules to strengthen the LV adsorption (CD-LV dissociation constant is three orders of magnitude lower than that for HSA-LF). We have found that (HSA-HPolS)conj+LV exhibited the highest activity against E. coli, whereas (HSA-HPCD)conj+LV was the most effective against B. subtilis; and both HSA conjugates were more potent than LV alone or LV with HSA. Further fine-tuning of HSA could yield an improvement in biodistribution, and thus a more favorable risk/benefit ratio.

The thionamide antithyroid drugs were discovered largely following serendipitous observations by numerous researchers in the 1940s who found that sulfhydryl-containing compounds were goitrogenic in animals. Prof. Edwin B. Astwood was the first to use these compounds to treat hyperthyroidism. In this review, we summarize the history of the development of these drugs and the coordination possibility of 2-thiouracil and its derivatives, as well as the biological activities of some of its complexes. Some of them are used as agents for the treatment of tuberculosis, and arthritis, others have bactericidal and fungicidal activity, the third cytotoxic properties, and could be used to treat various types of cancer.

The product of ozonolysis, Glycero-(9,10-trioxolane)-trioleate (ozonide of oleic acid triglyceride, [OTOA]), was incorporated into polylactic acid/polycaprolactone (PLA/PCL) blend films in the amount of 1, 5, 10, 20, 30, and 40% w/w. The morphological, mechanical, thermal and antibacterial properties of the biodegradable blend after the OTOA addition were studied. According to DSC and XRD data, the crystallinity degree of PLA/PCL+OTOA films tended to decrease with increase in OTOA content that could be explained by its plasticizing effect. Morphological analysis showed that the structure of the films with the OTOA concentration above 20% drastically changed. Specifically, the interface between the PLA/PCL matrix and OTOA was formed, thereby forming a capsule with the embedded antibacterial agent. The moisture permeability of the resulting PLA/PCL+OTOA films decreased due to the formation of uniformly distributed hydrophobic amorphous zones that prevents water penetration. This architecture affects the tensile characteristics of the films: strength decreases to 5.6 MPa, elastic modulus E by 40%. The behavior of film elasticity is associated with the redistribution of amorphous regions in the matrix. Additionally, PLA/PCL+OTOA films with 20, 30 and 40% of OTOA showed good antibacterial properties on Pseudomonas aeruginosa, Raoultella terrigena (Klebsiella terrigena) and Agrobacterium tumefaciens. Developed PLA/PCL+OTOA films could be used as packaging materials and wound dressings. By variation of the OTOA content, it is possible to tailor the physical-chemical and antibacterial properties of the developed films for various applications.

Irrigation is crucial in cleaning and disinfection of the root canal system, because endodontic instruments are unable to reach a large part of the root canal system (isthmuses, accessory canals, apical ramifications) and bacteria that can reside. Sodium hypochlorite (NaOCl) is currently used as irrigant in root canal therapies for its non-specific protheolytic and antimicrobial properties, but undesirable effects may be observed especially when used near the terminus of apical foramen. This study aims to evaluate antimicrobial properties of Thyme Essential Oil (TEO) used alone or in combination with NaOCl against different bacterial strains, especially Staphylococcus aureus and Streptococcus mutans. TEO non-cytotoxic concentration (9,28mg/mL) showed antimicrobial properties comparable to NaOCl after 1min of contact, both in presence of organic material (6% sheep blood). Moreover, the combination of TEO and NaOCl did not compromise their individual antimicrobial properties at the same time of contact. These data suggest that TEO could be used as antimicrobial irrigant in root canal therapies in association with NaOCl, to reduce concentration of NaOCl and its undesirable side effects. Due to the absence of cytotoxic effects at tested dilution, TEO could be safely used also near the terminus of apical foramen for its cytocompatibility.

The involved components of formulated blending, CNF and CuO NPs, were individually obtained by using a biorefinery strategy for agricultural waste valorization together with an optimized chemical precipitation, assisted by ultrasounds. The optimization of synthesis parameters for CuO NPs have avoided the presence of undesirable species which usually requires of later thermal treatment with associated costs. The aerogels-based structure, obtained by conventional freeze-drying, acted as 3D support for CuO NPs providing a good dispersion within the cross-linked structure of the nanocellulose and facilitating direct contact of the antibacterial phase against undesirable microorganisms. All samples showed a positive response against Escherichia coli and Staphylococcus aureus. An increase of the antibacterial response of the aerogels, measured by agar disk diffusion test, has been observed with the increase of CuO NPs incorporated, obtaining width of the antimicrobial “halo” (nwhalo) from 0 to 0.6 and 0.35 for S. aureus and E. coli, respectively. Furthermore, the aerogels have been able to deactivate S. aureus and E. coli in less than 5 hours when the antibacterial assays have been analyzed by broth dilution method. From CNF-50CuO samples, an overlap nanoparticles effect produced a decrease of the antimicrobial kinetic.

The search for new antibacterial agents that could decrease bacterial resistance is a subject that is continuously developing. The Gram-negative and Gram-positive bacteria have a metalloproteins group belonging to the M4 family. That is the main virulence factor of these bacteria. In this work, we have used a computational protocol based on the comprehensive analysis of the results of docking, molecular dynamics simulation, MM-PBSA, ligand efficiency, and ADME-Tox properties of ligand designed in silico in the previous manuscript using the Thermolysin from Bacillus thermoproteolyticus, a metalloprotein of the M4 family as a target. The principal results obtained were the designed ligands were adequately oriented in the thermolysin active center. The Lig783, Lig2177, and Lig3444 compounds were those with better dynamic behavior, however, when analyzing the results extracted from the ADME-Tox properties, only Lig783 was the best antibacterial agent candidate.

Different water treatment regiments are revealed to have potential in enriching antibiotic resistant bacteria (ARB). Advanced oxidation processes (AOPs) based disinfection techniques have been studied widely in the recent times due to their advantages over conventional treatment methods. However, bacterial response and adaptations against the hostile environments of AOPs is not clearly understood yet. Based on the existing knowledge on the ways in which bacteria surpass the antibiotic treatment, here we propose few important aspects of bacterial adaptation which could be true for AOPs as well since both antibiotics and AOPs generate reactive oxygen species (ROS) during their modes of action. We discuss the plausible role of ROS in the selection of ARB and bacterial heterogeneity as a strategy to bypass the lethal action of AOPs. Understanding bacterial adaptation during disinfection plays a vital role in devising strategies to outclass the bacterial survival. Hence, more importance should be given to such studies in the near future for the successful implementation of AOPs.

Citation frequencies represent the most significant contributions in any respective field. This bibliometric analysis aimed to identify and analyze the 100 most-cited publications in the field of antibiotics and to highlight the trends of research in this field. “All databases” of Clarivate Analytics' Web of Science was used to identify and analyze the 100 publications. The articles were then cross-matched with Scopus and Google Scholar. The frequency of citation ranged from 940 to 11051 for the Web of Science, 1053 to 10740 for Scopus, and 1162 to 20041 for Google Scholar. Five hundred thirteen authors made contributions to the ranked list, and Robert E.W. Hancock contributed in six articles, which made it to the ranked list. Sixty-six scientific contributions originated from the United States of America. In contrast, five publications were linked to the University of Manitoba, Canada, that was identified as the educational organization, which made the most contributions (n=5). According to the methodological design, 26 of the most cited works were review-type closely followed by 23 expert opinions/perspectives. Eight articles were published in Nature journal, making it the journal with the most scientific contribution in this field. Correlation analysis between the publication age and citation frequency was found statistically significant (P = .012).

Enteric septicemia of catfish, columnaris disease, and streptococcosis, caused by Edwardsiella ictaluri, Flavobacterium columnare, and Streptococcus iniae, respectively, are the most common bacterial diseases of economic significance for the pond-raised channel catfish Ictalurus punctatus industry. Several management practices are used by catfish farmers to prevent large financial losses from these diseases such as the use of commercial antibiotics and other chemicals. In order to discover environmentally benign alternatives, using a rapid bioassay, we evaluated a crude extract from the roots of muscadine Vitis rotundifolia against these fish pathogenic bacteria and determined that the extract was most active against F. columnare. Subsequently, several isolated compounds from the root extract were further evaluated against F. columnare. Among these isolated compounds, (+)-hopeaphenol (2) and (+)-vitisin A (3) were found to be the most active against F. columnare, with 24-h 50% inhibition concentrations of 4.0±0.7 and 7.7±0.6 mg/L, respectively, and minimum inhibitory concentrations of 9.1±0 mg/L for each compound. Efficacy testing of 2 and 3 is necessary to further evaluate the potential for these compounds to be used as antibacterial agents for managing columnaris disease.

Antimicrobial peptides and structurally related peptoids offer potential for the development of new antibiotics. However, progress has been hindered by challenges presented by poor in vivo stability (peptides) or lack of selectivity (peptoids). Herein, we have developed a process to prepare novel hybrid antibacterial agents that combine both linear peptoids (increased in vivo stability compared to peptides) and a nisin fragment (lipid II targeting domain). The hybrid nisin-peptoids prepared were shown to have low µM activity (comparable to natural nisin) against methicillin-resistant Staphylococcus aureus.

The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, which is one of the most common skin diseases. Acne vulgaris often associates with acne-related bacteria such as <i>Propionibacterium acnes</i>, <i>Staphylococcus epidermidis</i>, <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>, some of which exhibit a resistant against commercial antibiotics used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we evaluated <i>in vitro</i> antibacterial activity of chitosan-phytochemical conjugates against acne-related bacteria. Three of chitosan-phytochemical conjugates used in this study showed stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) exhibited the highest antibacterial activity against acne-related bacteria with minimum inhibitory concentration values of 8 μg/mL to 256 μg/mL. In addition, the MICs of antibiotics against antibiotic resistant <i>P. acnes</i> and <i>P. aeruginosa</i> strains were dramatically reduced in the combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration indices clearly revealed a synergistic antibacterial effect between CCA and the antibiotics. Thus, the median ∑FIC values against the antibiotic resistant bacterial strains were ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics.

Consumer preference not only dictates what food is consumed but how that food is produced. Ingredients in livestock feed that are not antibiotics, not genetically modified, not of animal origin, and that are nutrient-like, tend to be more acceptable to consumers, retailers, and producers. Mono- and diglycerides (MDG) fit these criteria, are commonly used in food, and are generally recognized as safe. But beyond being emulsifiers and a source of energy, MDG are also known to have antimicrobial, immune and microbiome modulation, and angiogenic activity. MDG in broiler diets have been shown to impact a variety of immune-related functions such as regulation of circulating antibodies, as well as decreased gene expression or protein concentration of pro-inflammatory cytokines like TNF-α, IL-1β, IL-6, and IFN-γ. In addition, MDG can affect metabolic function and intestinal integrity. Results of this review show that MDG can serve as antimicrobial and growth-supporting alternatives for reducing poultry production losses, improving resource utilization, and meeting consumer demand for sustainably produced and safe animal protein.

The design and engineering of antibacterial materials is key for preventing bacterial adherence and proliferation in biomedical and house-hold instruments. Silver nanoparticles (AgNPs) and chitosan (CHI) are broad-spectrum antibacterial materials with different properties, whose combined application is currently under optimization. This study proposes the formation of antibacterial films with AgNPs embedded in carboxymethylcellulose/chitosan multilayers by the layer-by-layer (LbL) method. The films were deposited onto nanoporous silicon (nPSi), an ideal platform for bioengineering applications, due to its biocompatibility, biodegradability, and bioresorbability. We focus on two alternative multilayer deposition processes: cyclic dip coating (CDC) and cyclic spin coating (CSC). The physicochemical properties of the films were the subject of microscopic, microstructural and surface-interface analyses. The antibacterial activity of each film was investigated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria strains as model microorganisms. According to the findings, CDC technique produced multilayer films with higher antibacterial activity for both bacteria compared to the CSC method. Bacteria adhesion inhibition was observed from only 3 cycles. The developed AgNPs-multilayer composite film offers advantageous antibacterial properties for biomedical applications.

The global burden of antimicrobial resistance is on the rise, resulting in higher morbidity and mortality in our communities. The spread of antimicrobial resistance in the environment and development of resistant microbes is a challenge to the control of antimicrobial resistance. Approaches, such as antimicrobial stewardship programmes, and enhanced surveillance, have been devised to curb its spread. However, particularly in lower- and middle-income countries, the overall extent of antimicrobial resistance, and knowledge on on-going surveillance, stewardship or investigation efforts, re often poorly understood. This study aimed to look at the efforts that have been undertaken to combat antimicrobial resistance in Uganda as a means of establishing an overview of the situation, to help inform future decisions. We conducted a systematic literature review of the PubMed database to assess the efforts that have been done in Uganda to investigate and combat antimicrobial resistance. A search combining keywords associated with antimicrobial resistance were used to look up relevant studies between 1995 and 2020 on surveillance of antimicrobial resistance in Uganda, and susceptibility of microbes to different drugs. The search yielded 430 records, 163 of which met the inclusion criteria for analysis. The studies were categorized according to country and region, the type of antimicrobial resistance, context of the study, study design and outcome of the study. Antibacterial resistance and antimalarial resistance had the most published studies while antiviral and antifungal resistance each were represented by very few studies. Most studies were conducted in humans and hospital settings, with very few in veterinary and One Health contexts. The results from our work can inform public health policy on antimicrobial stewardship as it contributes to understanding the status of antimicrobial resistance surveillance in Uganda, and can also help to guide future research efforts. Notably, a One Health approach needs to be followed with re-spect to surveillance of antimicrobial resistance to better understand the mechanisms of resistance transfer across the human-animal–environment interface, including additional investigation in antiviral and antifungal resistance.

This study aimed to evaluate the effects of a palygorskite-based antibacterial agent (PAA) as an alternative to antibiotics on growth performance, blood parameters, rumen fermentation, and rumen microbiota in sheep. A total of 120 sheep were randomly divided into five groups of six replicates with four sheep each. Sheep were fed a basal diet, an antibiotic diet supplemented with 500 g/t chlortetracycline (CTC), and a basal diet supplemented with 500, 1,000, and 2,000 g/t PAA for 80 d, respectively. Supplementation with 2,000 g/t PAA and 500 g/t CTC increased the average daily gain (ADG) of sheep compared with the control group (P < 0.05). Diets supplemented with 2,000 g/t PAA and 500 g/t CTC reduced (P < 0.05) the feed: gain (F/G ratio) in the overall periods. Dietary Supplementation with 1,000 g/t PAA significantly increased albumin and total protein (P < 0.05). A significant positive correlation was found between growth hormone concentration and PAA supplementation (P < 0.05). In addition, compared to the control group, the CTC group had higher growth hormone concentration and lower lipopolysaccharide concentration (P < 0.05). No dif-ference was observed between the five groups in terms of rumen fermentation characteristics (P > 0.05). At the phylum level, the relative abundance of Proteobacteria was lower in the PAA 2000 and CTC 500 groups than that in the control and PAA 500 groups (P < 0.05). At the genus level, a sig-nificant decrease (P < 0.05) in the relative abundance of RuminococcaceaeUCG-010 was observed in the PAA 1000, PAA 2000, and CTC 500 groups compared with that in the control group. In addition, the relative abundance of Prevotella1 (P < 0.05) was higher in the PAA 2000 group than that in the control group. These findings indicate that dietary supplementation with PAA has ameliorative effects on growth performance, blood parameters, and rumen microbiota, with an optimal dosage of 2,000 g/t for sheep.

In this work, we pursued the biological characterization of the venom of Montivipera born-muelleri, a viper from the Lebanese mountains. In relativity to its antibacterial potential, the in-hibitory effect of this venom on the F1F0-ATPase enzymes of Gram-positive Staphylocoocus epider-midis and Gram-negative Escherichia coli bacteria was examined. In order to determine the de-gree of cytotoxicity of the venom on the HCT116 human colon cancer cell lines, the biological MTT proliferation and cell viability test were implemented. After validation of the enzymatic F1F0-ATPase model by the spectrophotometric method, using quercetin as the reference ligand, re-sults revealed that M. bornmuelleri venom is able to inhibit the activity of the enzyme of these two bacteria with a concentration of the order of 100-150 µg/mL. In addition, a venom concentration of 10 µg/mL was sufficient to kill the totality of HCT116 cell lines cultivated in vitro. These data show that M. bornmuelleri venom is a mixture of diverse molecules presenting activities of interest and is a potential source to explore in order to discover new drug candidates.

Antibiotic-loaded bone cements are widely used in orthopedic surgery. However, they present issues such as a short antibiotic release time and the antibiotic resistance. These challenges necessitate the development of novel antibacterial bone cements. Non-leaching bone cement containing antibacterial motifs represents a promising advancement in this direction. Antibacterial motifs are incorporated into the cement either covalently or non-covalently, and while they will not be released, they will still exhibit surface antibacterial activity. This review comprehensively examines the structure and antimicrobial activity of prevalent non-leaching antimicrobial bone cements. Additionally, it delves into the characteristics of current methods employed for detecting surface antimicrobial activity. Finally, the future research direction of non-leaching antibacterial bone cement is discussed, with a specific focus on innovative antibacterial motifs, the mechanisms underlying non-leaching antibacterial properties, and the potential synergies achievable by combining non-leaching antibacterial bone cement with traditional antibiotics.

This study describes an eco-friendly synthesis of ZnO nanoparticles using aqueous oat extract. The advanced electrochemical and optical features of green synthesized ZnONPs displayed excellent antibacterial activity, and exhibited an important role in pharmaceutical determinations. The formation of nanoscale ZnO was confirmed using various spectroscopic and microscopic investigations. The formed nanoparticles were found to be around 100 nm. The as-prepared ZnONPs were monitored for their antibacterial potential against different bacterial strains. The inhibition zones for ZnONPs were found as E. coli (16 mm), P. aeruginosa (17 mm), S. aureus (12 mm) and B. subtilis (11 mm) using 30 µg mL-1 sample concentration. Also, ZnONPs exhibited significant antioxidant effects 58 to 67 % with an average IC50 value of 0.88 ± 0.03 scavenging activity and 53 to 71 % (IC50 value 0.73 ± 0.05) against the DPPH and ABTS scavenging free radicals, respectively. The photocatalytic potential of ZnONPs for Rhodamine B dye degradation dye under UV irradiation was performed. The photodegradation process was carried out as a function of time-dependent and the complete degradation (nearly 98 %) with color removal after 120 min. Conclusively, the synthesized ZnONPs using oat biomass might provide a great promise in the future for biomedical applications.

Four leather substrates from different animals were treated by dispersions containing hydrophilic composite silica-hyperbranched poly(ethylene imine) xerogels. Antimicrobial activity was introduced by incorporating silver nanoparticles and /or benzalkonium chloride. The gel precursor solutions were also infused before gelation to titanium oxide powders typically employed for induction of self-cleaning properties. The dispersions from these biomimetically premade xerogels integrate environmentally friendly materials with short coating times. Scanning electron microscopy (SEM) provided information on the powder distribution onto the leathers. Substrate and coating composition were estimated by infrared spectroscopy (IR) and ener-gy-dispersive X-ray spectroscopy (EDS). Surface hydrophilicity and water permeability were assessed by water-contact angle experiments. The diffusion of the leather's initial components and xerogel additives into the water were measured by Ultraviolet-Visible (UV-Vis) spectroscopy. Protection against GRAM- bacteria was tested for Escherichia coli, Pseudomonas aeruginosa, and Klebsiella Pneumoniae against GRAM+ bacteria for Staphylococcus aureus, and Enterococcus faecalis and against fungi for Candida albicans. Antibiofilm capacity experiments were performed against Staphylococcus aureus, Klebsiella Pneumoniae, Enterococcus faecalis, and Candida albicans. The application of xerogel dispersions proved an adequate and economically feasible alternative to the direct gel formation into the substrate’s pores for the preparation of leathers intended for medical uses

Positively charged polyelectrolytes hold significant potential as materials for creating antibacterial coatings. Water-soluble macromolecules can be easily deposited onto a treated surface through various techniques, forming a film that provides antimicrobial properties to the surface through electrostatic interactions with bacterial membranes. The structural and molecular weight characteristics of the polymers play a crucial role in the physical and mechanical properties of the coatings. In this study, we investigated the properties of branched polyethyleneimine (PEI) and linear polydiallyldimethylammonium chloride (PDADMAC) coatings with different molecular weights of polymer samples to determine their suitability as stable coatings with antibacterial properties against foodborne bacteria. Using thermogravimetric analysis, dynamometry, and dynamic light scattering, we examined the physicochemical and mechanical properties of the macromolecules in water solutions and in coatings. Microbiological study was conducted to analyze the biocidal activity of the polycations in solutions and on the surface of coatings. Our findings showed that the moisture saturation of the polycationic coatings did not significantly depend on the chemical nature of charged groups or the molecular weight or architecture of macromolecules. Moreover, biocidal activity was not found to depend on the molecular weights of PEI and PDADMAC. However, the lowering of the molecular weight of polymers resulted in the loss of cohesive forces in the coatings and to dramatically loss of the stability towards wash-off with water. The diffusion coefficient (D0) of macromolecules was identified as a key parameter for the wash-off mechanism. Films formed by molecules with D0 below 1×10-7 cm2/s demonstrated high resistance to wash-off procedures. We demonstrated that PEI and PDADMAC samples with high molecular weights showed high antimicrobial activity towards L. monocytogenes. Our results highlight the importance of macromolecule characteristics in the development of new biocidal coatings based on polycations.

This work aimed to identify chemical compounds of Cinnamomum burmannii leaf essential oil (CBLEO) and to unravel antibacterial mechanism of CBLEO at molecular level for developing antimicrobial. CBLEO had 37 volatile profiling with abundant borneol (28.40 %), and showed good potential to control foodborne pathogens, of which Staphylococcus aureus had the greatest inhibition zone diameter (28.72 nm) with the lowest values of minimum inhibitory concentration (1.0 μg/mL) and bactericidal concentration (2.0 μg/mL). To unravel antibacterial action of CBLEO on S. aureus, a dynamic exploration of antibacterial growth, material leakage, ROS formation, protein oxidation, cell morphology and interaction with genome DNA were conducted on S. aureus exposed to CBLEO at different doses (1/2-2×MIC) and times (0-24 h), indicating that CBLEO acts as inducer for ROS production and oxidative stress of S. aureus. To highlight antibacterial action of CBLEO on S. aureus at molecular level, a comparative association of ROS accumulation with some key virulence-related gene (sigB/agrA/sarA/icaA/cidA/rsbU) transcription, protease production and biofilm formation in S. aureus subjected to CBLEO at different levels and times, revealing that CBLEO-induced oxidative stress caused transcript suppression of virulence regulators (RsbU and SigB) and its targeted genes, causing protease level increase destined for biofilm formation and growth inhibition of S. aureus, which may be as key bactericidal action. Our findings provide valuable information for studying the antibacterial mechanism of essential oil against pathogens.

To combat infections on biomedical devices, antimicrobial coatings have attracted considerable attention, including coatings comprising naturally occurring antimicrobial peptides (AMPs). In this study the aim was to explore performance upon extended challenge by bacteria growing in media above samples. The AMPs LL37, Magainin 2, and Parasin 1 were covalently grafted onto a plasma polymer platform, which enables application of this multilayer coating strategy to a wide range of biomaterials. Detailed surface analyses were performed to verify the intended outcomes of the coating sequence. Samples were challenged by incubation in bacterial growth media for 5 and 20 hrs. Compared with the control plasma polymer surface, all three grafted AMP coatings showed considerable reductions in bacterial colonization even at the high bacterial challenge of initial seeding at 1x107 CFU, but there were increasing numbers of dead bacteria attached to the surface. All three grafted AMP coatings were found to be non-toxic to primary fibroblasts. These coatings thus could be useful to produce antibacterial surface coatings for biomaterials, though possible consequences arising from the presence of dead bacteria need to be studied further, and compared to non-fouling coatings that avoid attached dead bacteria.

Cariogenic oral biofilms cause a considerable amount of recurrent dental caries around composite restorations every year, resulting in unprosperous oral health status and expensive restorative treatment for many patients. Quaternary ammonium monomers that can be copolymerized with the current dental resin systems have been increasingly explored for modulation of dental plaque biofilm growth over dental composite surfaces. Here, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM), against human overlying mature oral biofilms grown intra-orally in human participants for 7 and 14 days, for the first time. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected for determination of bacterial counts via colony-forming unit (CFU) counts. The biofilm viability, chronological changes, and percentage coverage were also determined by live/dead staining. QADM composites caused a significant inhibition of S. mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that (1) QADM composite was successful in inhibiting 1-3 day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of S.mutans group in a time course where patients at high risk of caries would develop initial enamel carious lesions; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. These results provide a perspective on the value of integrating bioactive restorative materials with traditional caries management approaches into clinical practice. Contact-killing strategies via dental materials aiming to prevent or at least reduce high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of recurrence of dental caries around composites.

Biosurfactants (BSs) are microbial compounds that have emerged as potential alternatives to chemical surfactants due to their multifunctional properties, sustainability, and biodegradability. Owing to their amphipathic nature and distinctive structural arrangement, biosurfactants exhibit a range of physicochemical properties, including excellent surface activity, efficient critical micelle concentration, humectant properties, foaming and cleaning abilities and the capacity to form microemulsions. Furthermore, numerous biosurfactants display additional biological characteristics, such as antibacterial, antifungal, and antiviral effects, antioxidant, anticancer, and immunomodulatory activities. Over the past two decades, numerous studies have explored their potential applications, including pharmaceuticals, cosmetics, antimicrobial and antibiofilm agents, wound healing, anticancer treatments, immune system modulators and drug/gene carriers. These applications are particularly important in addressing challenges such as antimicrobial resistance and biofilm formation in clinical, hygiene, and therapeutic settings. They can also serve as coating agents for surfaces, enabling antiadhesive, suppression, or eradication strategies. Not least importantly, biosurfactants have shown compatibility with various drug formulations, including nanoparticles, liposomes, micro and nanoemulsions, and hydrogels, improving drug solubility, stability, and bioavailability and enabling targeted and controlled drug release. These qualities make biosurfactants promising candidates for the development of next-generation antimicrobial, antibiofilm, anticancer, wound healing, immunomodulating, drug or gene delivery agents, as well as adjuvants to other antibiotics. Analyzing recent literature, this review aims to provide insights into the present understanding, highlight emerging trends, identify promising directions and advancements in the utilization of biosurfactants within the pharmaceutical and biomedical fields.

Here, we report on ZnO nanoparticles (NPs) generated by nanosecond pulsed laser (Nd:YAG, 1064 nm) through ablation of metallic Zn target in water and air and their comparative analysis as potential nanomaterials for biomedical applications. The prepared nanomaterials were carefully characterized in terms of their structure, composition, morphology and defects. It was found that in addition to the main wurtzite ZnO phase, which is conventionally prepared and reported by others, the sample laser-generated in air also contained some amount of monoclinic zinc hydroxynitrate. Both nanomaterials were then used to modify model wound dressings based on biodegradable poly-L-lactic acid. The as-prepared model dressings were tested as biomedical materials with bactericidal properties towards S. aureus and E. coli strains. The advantages of the NPs prepared in air over their counterparts generated in water found in this work are discussed.

Carvacrol is well-documented for its antibacterial and antioxidant effects. However, its high volatility has directed researchers towards nanoencapsulation technology according to bioeconomy and sustainability trends. This study examined and compared carvacrol microemulsion (MC), carvacrol microemulsion busted with chitosan (MMC) and carvacrol nanoemulsions as active coatings on extending minced pork meat shelf-life at 4±1 oC for 9 days, focusing on microbiological, physiochemical, and sensory characteristics. The research involved pre-characterizing droplet sizes, evaluating antioxidant, and determining antibacterial efficacy. The results demonstrated that NC with a 21 nm droplet size exhibited the highest antioxidant and antibacterial activity. All coatings succeed to extend the preservation of fresh minced pork meat in comparison to free carvacrol sample (FC). NC coating showed the highest extension of minced pork meat preservation and maintained meat freshness for 9 days, with a lower TBARs of 0.736 mg MDA/Kg, and effectively reduced mesophilic, lactic acid, and psychrotrophic bacterial counts more significantly 1.2, 2, and 1.3 log respectively as compared to FC. Sensory assessments confirmed the acceptability of NC and MCC coatings. Overall, the carvacrol based nanoemulsion can be considered as novel antioxidant and antimicrobial active coating due to its demonstrated higher efficacy in all the examined tests performed.

In recent years, antibacterial coatings have become a significant approach in the global fight against bacterial pathogens. Developments in materials science, chemistry and biochemistry have led to a plethora of materials and chemical compounds that have potential for creating antibacterial coatings. Nonetheless, there has been insufficient consideration given to the analysis of the techniques and technologies used to apply these coatings. Among the various inorganic coating techniques, Atomic Layer Deposition (ALD) is noteworthy. It enables the successful synthesis of high-purity inorganic nanocoatings on surfaces of complex shape and topography, while also providing precise control over their thickness and composition. ALD has various industrial applications, but its practical application in medicine is still limited. In recent years, a substantial number of papers have been published on the suggested implementation of thin films and coatings produced through ALD in medicine, notably those with antibacterial properties. The aim of this paper is to carefully evaluate and analyse the relevant literature on this subject. Simple oxide coatings, including TiO2, ZnO, Fe2O3, MgO, and ZrO2, were examined, as well as coatings containing metal nanoparticles such as Ag, Cu, Pt, and Au, and mixed systems such as TiO2-ZnO, TiO2-ZrO2, ZnO-Al2O3, TiO2-Ag, and ZnO-Ag. Through comparative analysis, we have been able to draw conclusions on the effectiveness of various antibacterial coatings of different compositions, including key characteristics such as thickness, morphology, and crystal structure. ALD has been analysed in its use for developing antibacterial coatings for various applications. Furthermore, assumptions regarding the most promising development areas have been presented.

Food saving and further valorization is of major interest in our days. Worldwide, scientists intensify their efforts to increase shelf life of products due to the global danger of coming food crisis. Even though many chemicals could achieve such target, the circular economy spirit and the global trend against the greenhouse effects impose the turn of research activities using environmentally friendly biomass materials, biowastes, and biodegradable materials. In this study, the promising biopolymer chitosan incorporated with the promising biodegradable polymer poly-vinyl-alcohol to produce a biopolymeric matrix. This biodegradable biopolymer was further mixed homogeneously with 15% thymol/nano-zeolite nanohybrid material and the final developed film was extremely improved compared to the relevant of chitosan/poly-vinyl-alcohol film. Mechanical properties were increased significantly i.e., 34% for Young Modulus and 46,5% for ultimate tensile strength, while the antioxidant activity increased by 53,4%. The antibacterial activity increased by 134% for Ecoli, 87,5% for Saureus, 32% for Lmonocytogenes, and 9% for Senterica. The water-vapor diffusion coefficient and the oxygen permeability coefficient decreased down to -51% and -74% respectively, and thus the water-vapor and oxygen barrier increased. In-vivo experiments on strawberries show an extension of 233% for shelf-life duration which resulted from the modified atmosphere by the control-released thymol.

Magnetic nanoparticles based on iron oxides (MNPs-Fe) with magnetite or maghemite phases have been widely employed in bio-applications. Thus, they have been used as contrast agents in magnetic resonance imaging (MRI) and oncological treatments through different therapies. Besides, due to the vast health problem of multidrug-resistant bacterial infections, several studies have proposed MNPs-Fe as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT). This work presents a quick and easy green synthesis (GS) to obtain MNPs-Fe using orange peel extract from orange waste from local commerce, which presents an environmentally friendly approach compared to traditional methods such as coprecipitation. The GS can be irradiated with microwaves to reduce the synthesis time drastically. We evaluated the weight yield of the GS and the physical-chemical and magnetic features of the synthesized MNPs-Fe. Besides their cytotoxicity in animal cell line ATCC RAW 264.7, their antibacterial activity against Staphylococcus Aureus (S. Aureus) and Escherichia Coli (E. Coli) was assessed. We found that the MNPs-Fe synthesized using the GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract (50GS-MNPs-Fe) had an excellent weight yield, negligible cytotoxicity for concentrations of MNPs-Fe below 250 µg·mL-1 in 24 hours, and 8 days. In the MNPs-Fe surface, we identified a coating of organic molecules (~ 25 nm) such as terpenes, aldehydes, etc. MNPs-Fe inhibited S. Aureus and 2.54 log10 (CFU) of E. Coli under red LED light irradiation (630 nm, 65.5 mW·cm-2, 30 min). Likewise, they exhibited a superparamagnetic (SPM) behavior for temperatures above 60 K, with a size of 49.3±9.6 nm and saturation magnetization (Ms) of 72.83 and 44.16 emu·g-1 at 60 and 300 K, respectively. Therefore, 50GS-MNPs-Fe are excellent candidates as broad-spectrum PTAs in antibacterial PTT, magnetic hyperthermia (MH), or MRI.

The design of biomaterial platforms able to release bioactive molecules is mandatory in tissue repair and regenerative medicine. In this context, electrospinning is a user-friendly, versatile and low-cost technique, able to process different kinds of materials in micro- and nano-fibers with a large surface area-to-volume ratio for an optimal release of gaseous signalling molecules. Recently, the antioxidant and anti-inflammatory properties of the endogenous gasotramsmitter hydrogen sulfide (H2S), as well as its ability to stimulate relevant biochemical processes on the growth of mesenchymal stem cells (MSC), have been investigated. Therefore, in this work, new poly(lactic) acid fibrous membranes (PFM), doped and functionalized with H2S slow-releasing donors extracted from garlic, were synthetized. These innovative H2S-releasing mats were characterized for their morphological, thermal, mechanical and biological properties. Their antimicrobial activity and effects on the in vitro human cardiac MSC growth, either in the presence or in the absence of oxidative stress, were here assessed. On the basis of the results here presented, these new H2S-releasing PFM could represent promising and low-cost scaffolds or patches for biomedical applications in tissue repair.

Metal complexes feature a wide range of available geometries, diversified lability, controllable hydrolytic stability, and easily available rich redox activity. These characteristics combined with the specific properties of the coordinated organic molecules result in many different mechanisms of biological action, making each of the myriads of the classes of metal coordination compounds unique. This focused review presents combined and systematized results of the studies of a group of copper(I) (pseudo)halide complexes with aromatic diimines and tris(aminomethyl)phosphines of a general formula [CuX(NN)PR₃], where X = I^- or NCS^-, NN = 2,2’-bipyridyl, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline or 2,2’-biquinoline, and PR₃ = Air-stable tris(aminomethyl)phosphines. The structural and electronic properties of the phosphine ligands and luminescent complexes are discussed. The complexes with 2,9-dimethyl-1,10-phenanthroline, apart from being air- and water-stable, exhibit a very high in vitro antimicriobial activity against the Staphylococcus aureus and Candida albicans. Moreover, some of the complexes also show a strong in vitro antitumor activity against human ovarian carcinoma cell lines: MDAH 2774 and SCOV 3, CT26 (mouse colon carcinoma), and A549 (human lung adenocarcinoma) cell lines. The tested complexes are moderately able to induce DNA lesions through free radical processes, however the trends do not reflect observed differences in biological activity.

Childhood diarrhea continues to be a major cause of under-five (U-5) mortality globally and in India. In this study, 1571 U-5 children residing in nine rural villages and four urban slums in Ujjain, India were included with the objective to use community participation and drug utilization research to improve diarrheal case management. The mean age was 2.08 years, with 297 (19%), children living in high diarrheal index households. Most mothers (70%) considered stale food, teething (62%), and hot weather (55%) as causes of diarrhea. Water, sanitation, and hygiene (WASH)-related characteristics revealed that most (93%) households had toilets, but only 23% of the children used them. The study identified ineffective household water treatment by filtration through cloth by most (93%) households and dumping of household waste on the streets (89%). The results revealed low community awareness of correct causes of diarrhea (poor hand hygiene, 21%; littering around the household, 15%) and of correct diarrhea treatment (oral rehydration solution (ORS) and zinc use, 29% and 11%, respectively) and a high antibiotic prescription rate by healthcare providers (83%). Based on the results of the present study, context-specific house-to-house interventions will be designed and implemented.

Wound infections evidently appeared in times of World War I that accounted a significant mortality and morbidity rate among injured soldiers. Currently, around 11 million people worldwide require medical treatment for wound infections and 300,000 die every year due to untreated wound infection. The extensive use of antibiotics to treat wound infection leads to emerging new microbial strains that are resistant to many antibiotics. There is a growing concern on the emergence and re-emergence of drug-resistant pathogens such as multi-resistant bacterial strains. Hence, the development of new antimicrobial compounds or the modification of those that already exist to improve antibacterial activity is a high priority area of research. During the past few decades, nanotechnology has arisen with new promising technology for synthesis of nanobiomaterials. Metallic nanoparticles (NPs) are considered as new alternative treatment with superior antibacterial activity. In this study, new formulation of titanium oxide (TiO2) NPs with different sizes were synthesized and characterized. Genotoxicity, mutagenicity and antibacterial activities of TiO2 NPs against the causative agents of wound infection were investigated. Antibacterial activity of TiO2 NPs was conducted against three ATCC ® bacterial strains: methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Pseudomonas aeruginosa. The results clearly illustrate a superior antibacterial activity of all newly formulated TiO2 NPs against the most causative agents of wound infection. Most of our TiO2 NPs showed non-genotoxic and non-mutagenic results at the maximum concentrations. Findings of this study will enhance the future of the therapeutic strategies against the resistant pathogenic strains that cause wound infections.

Abstract Antibacterial activities can be improved using mixed ligands. Mixed ligands involved in this research are sodium sulfadiazine (Na-sfz) and dithiocarbamate (ai-dtc). One-pot synthesis was used to synthesize ligand of aniline dithiocarbamate (ai-dtc) and the corresponding coordination compounds of [VO(sfz)(ai-dtc)] and [Zn(sfz)(ai-dtc)]. Crystals of ai-dtc, which grew from the solution when refrigerated after five days, were diffracted with technique of single crystal x-ray crystallography to reveal the structure. Other characterization techniques involving physicochemical parameters, FT-IR, UV-Vis and NMR (1H NMR and 13C NMR) were carried out on ligands of ai-dtc, sfz and corresponding coordination compounds. Differences in results of FT-IR, UV-Vis and NMR between ligands and their respective metal ions confirmed the coordination. The in vitro antibacterial studies showed that the ligands (not the metal complexes) had modest activity against Gram negative bacteria: Staphylococcus aureus, whereas, the coordination compounds had modest activities against the Gram negative bacteria: Escherichia coli and Pseudomonas aeruginosa.

The purpose of the study was to investigate the bacterial viability of the initial biofilm on the surface of experimental modified dental resin composites. Twenty-five healthy individuals with good oral hygiene were included in this study. In a split-mouth design, they received acrylic splints with five experimental composite resin specimens. Four of them were modified with either a novel polymeric hollow beads delivery system or methacrylated polymerizable Irgasan (Antibacterial B), while one specimen served as unmodified control (ST). The delivery system based on Poly-Pore® was loaded with one of the active agents Tego® Protect 5000 (Antiadhesive A), Dimethicone (Antiadhesive B) or Irgasan (Antibacterial A). All study subjects refrained from toothbrushing during the study period. Specimens were detached from the splints after 8h and given a live/dead staining before fluorescence microscopy. Friedman test and post-hoc Nemenyi test were applied with significance level at p &lt; 0.05. In summary all materials but Antibacterial B showed a significant antibacterial effect compared to ST. In conclusion dental resin composites with Poly-Pore loaded active agents show antibacterial effectiveness in situ.

Musculoskeletal infections (MIs) are among the most difficult-to-treat staphylococcal diseases. The limited availability of effective antibiotics has encouraged the development of innovative strategies such as combinatory therapy to combat MI. The aim of this study was to investigate the in vitro antistaphylococcal activity of anti-inflammatory and the antimicrobial combinatory effect of celecoxib with oxacillin. The minimum inhibitory concentrations (MICs) of 17 anti-inflammatory drugs were determined for standard strains and clinical isolates of S. aureus strains, counting methicillin-resistant strains (MRSA), by the broth microdilution method. The fractional inhibitory concentration indices (FICIs) were evaluated by the checkerboard assays. Celecoxib produced the most potent antistaphylococcal effect against all the tested strains (MIC ranging from 32 to 64 mg/mL), followed by diacerein against MRSA3 and MRSA ATCC 33592 (MIC 64 mg/mL). Several synergistic effects were observed for tested S. aureus strains, including MRSA (FICI ranging from 0.087 to 0.471). The strongest synergistic interaction (FICI 0.087) was obtained against MRSA ATCC 33592 at a celecoxib concentration of 2 mg/mL with a 19-fold oxacillin MIC reduction (from 512 to 26.888 mg/mL). This is the first report on the antistaphylococcal combinatory effect of celecoxib with oxacillin. Our findings suggest celecoxib and its combination with oxacillin as perspective agents for research focused on the development of novel therapies for MI caused by S. aureus. Thus, this study presents novel findings that celecoxib could, in some cases, resensitise MRSA strains to become susceptible to certain β-lactams (e.g., oxacillin) not previously tested.

Hybrid organic-inorganic (dendritic polymer-silica) xerogels containing silver nanoparticles (Ag-Nps) were developed as antibacterial leather coatings. The preparation method is environmentally friendly, based on two biomimetic reactions. Silica gelation and spontaneous (Ag-Np) formation were both mediated by hyperbranched poly (ethylene imine) (PEI) scaffolds of variable Mw (2000-750000). The formation of precursor hydrogels was monitored by dynamic light scattering (DLS). The chemical composition of the xerogels was assessed by Infra-Red Spectroscopy (IR) and Energy-dispersive X-ray spectroscopy (EDS) while the uniformity of the coatings was established by scanning electron microscopy (SEM). Release properties of coated leather samples and overall behaviour in water in comparison to untreated analogs were investigated by UV-Vis spectroscopy. Antibacterial activity was tested towards Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, and antibiofilm properties against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Acinetobacter baumannii, Enterococcus faecalis while SARS-Cov-2 clinical isolate was employed for the first estimation of their antiviral potential. Toxicity was evaluated using the Jurkat E6.1-cell line. Finally, water contact angle measurements were implemented to determine the enhancement of the leather surface hydrophilicity caused by these composite layers. The final advanced products are intended for use in medical applications.

Biofilm-associated bacterial infections are the major reason for treatment failure in many diseases including burn trauma infections. Uncontrolled inflammation induced by bacteria leads to materiality, tissue damage and chronic diseases. Specialized proresolving mediators (SPMs), including maresin-like lipid mediators (MarLs), are enzymatically biosynthesized from omega-3 essential long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA) by macrophages and other leukocytes. SPMs exhibit strong inflammation-resolving activities, especially inflammation provoked by bacterial infection. In this study, we explored the potential direct inhibitory activities of three MarLs on gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria in their biofilms that are leading bacteria in burn trauma related infections. We also examined the effects of MarLs on the bactericidal activities of a typical broad-spectrum antibiotics carbenicillin on these bacteria in their preformed biofilms. The results revealed that MarLs combined with carbenicillin can inhibit the survival of gram-positive and gram-negative bacteria in their biofilms although MarLs alone did not exhibit bactericidal activity. Thus, our findings suggest that the combination of MarLs and carbenicillin can lower the antibiotic requirements to kill the bacteria in preformed biofilms.

Brevibacillus laterosporus (Bl) is a Gram-positive and spore-forming bacterium belonging to the Brevibacillus brevis phylogenetic cluster. Globally, insect pathogenic strains of the bacterium have been isolated, characterised, and some activities patented. Two isolates, Bl 1821L and Bl 1951, exhibiting pathogenicity against the diamondback moth and mosquitoes, are under development as a biopesticide in New Zealand. However, due to the suspected activity of putative antibacterial proteins (ABPs), the endemic isolates often grow erratically. Various purification methods including size exclusion chromatography, sucrose density gradient centrifugation, polyethylene glycol precipitation, and ammonium sulphate precipitation employed in this study enabled the isolation of two putative antibacterial proteins of ~30 kD and ~48 kD from Bl 1821L and one putative antibacterial protein of ~30 kD from Bl 1951. Purification of the uninduced cultures of Bl 1821L and Bl 1951 also yielded the protein bands of ~30 kD and ~48 kD on SDS-PAGE which indicated their spontaneous induction. Disc diffusion assay was used to determine the antagonistic activities of the putative ABPs. Subsequent transmission electron microscope (TEM) examination of purified putative antibacterial protein-containing solution showed the presence of encapsulin (~30 kD) and polysheath (~48 kD) like structures. Although only the ~30 kD protein was purified from Bl 1951, both structures were seen in this strain under TEM. Furthermore, while assessing the antibacterial activity of some fractions of Bl 1951 against Bl 1821L in size exclusion chromatography method, population of Bl 1821L persister cells was noted. Overall, this work added a wealth of knowledge for the purification of the HMW proteins (bacteriocins) of the Gram-positive bacteria including Bl.

Many stable water dispersions of various chemical compositions containing bioactive chemical compounds: copper silicate, titanium dioxide and zinc oxide (and other auxiliary substances) were developed and fabricated - they were used for preparation of thin hybrid coatings having very good antimicrobial properties against gram negative bacteria (Escherichia coli), gram positive bacteria (Staphylococcus aureus) and yeast fungus (Candida albicans). Polyester (PES) nonwovens were modified by dip-coating, and PES and cotton fabrics - by dip-coating and coating methods.

Natural products have long played a major role in medicine and science. The garden snail Cornu aspersa is a rich source of biologically active natural substances which might be an important source for new drugs to treat human disease. Based on our previous studies seven fractions containing compounds with Mw &lt;3 kDa, &lt;10 kDa, &lt;20 kDa, &gt;20 kDa, and between 3-5 kDa, 5-10 kDa, and 10-30 kDa were purified from the mucus of C. aspersa and analyzed by tandem mass spectrometry (MALDI-TOF/TOF). Seventeen novel peptides with potential antibacterial activity have been identified by de novo MS/MS sequencing using tandem mass spectrometry. The different fractions were tested for antibacterial activity against Gram─ (Pseudomonas aureofaciens and Escherichia coli) and Gram+ (Brevibacillus laterosporus) bacterial strains as well anaerobic bacterium Clostridium perfringens. These results revealed that the peptide fractions exhibit a predominant antibacterial activity against B. laterosporus, the fraction with Mw 10 – 30 kDa against E. coli, another peptide fraction &lt;20 kDa against P. aureofaciens, and the protein fraction &gt;20 kDa against the bacterial strain C. perfringens. The discovery of new antimicrobial peptides (AMPs) from natural sources is of great importance for public health due to their effective antimicrobial activities and low resistance rates.