Antibiotic resistance is now a first-order health problem, which makes the development of new families of antimicrobials an imperative. These compounds should ideally be inexpensive, readily available, highly active and non-toxic. Here we present the results on the antimicrobial activity of a series of natural and synthetic polyamines with different architectures (linear, tripodal and macrocyclic) and their derivatives containing the oxygen containing aromatic functional groups 1,3-benzodioxol, ortho/para phenol or 2,3-dihydrobenzofuran. The new compounds were prepared through a non-expensive process and their activity was tested against selected strains of yeast, gram-positive and gram-negative bacteria. In all cases, the conjugated derivatives showed antimicrobial activity higher than the unsubstituted polyamines. Several factors, such as the overall charge at physiological pH, the lipophilicity and the topology of the polyamine scaffold were relevant to their activity. The nature of the lipophilic moiety was also determinant on human cell toxicity. The lead compounds showed to be bactericidal and fungistatic, and they were synergic with the commercial antifungals fluconazole, cycloheximide and amphotericin B against the yeast strains tested.

Macroalgae seaweeds such as Ulva lactuca and Gracilaria verrucosa cause problems on the Northern Coast of the Italian Adriatic Sea because their overabundance hinders the growth of cultivated clams, Rudatapes philippinarum. This study focused on the green synthesis of CuO nanoparticles from U. lactuca and G. verrucosa. The biosynthesized CuO NPs were successfully characterized using FTIR, XRD, HRTEM/EDX, and zeta potential. Nanoparticles from the two different algae species are essentially identical, with the same physical characteristics and almost the same antimicrobial activities. We have not investigated the cause of this identity, but it seems likely to arise from the reaction of Cu with the same algae metabolites in both species. The study demonstrates that it is possible to obtain useful products from these macroalgae through a green synthesis approach and that they should be considered as not just a cause of environmental and economic damage but also as a potential source of income.

The study evaluated potassium peroxymonosulfate (PPMS) efficacy against rifampicin-resistant Salmonella Infantis (rif-SI), Escherichia coli (E. coli), Salmonella Infantis (SI), Newcastle disease virus (NDV) and avian influenza virus (AIV). The assessment encompassed varied concentrations, organic material conditions, and exposure durations to comprehensively evaluate PPMS efficacy. Moreover, PPMS’s efficacy was tested on diverse carrier surfaces and clothing to evaluate its bactericidal and virucidal potential. At the recommended concentrations (1X), PPMS effectively inactivated all pathogens within 5 sec, except for NDV, which required 30 sec in the presence of organic materials. At 0.5X, PPMS successfully inactivated E. coli, AIV and NDV within 5 sec in the absence of organic material. However, rif-SI and SI necessitated 30 sec for inactivation. Most pathogens were inactivated within 30 sec, with the exception for AIV, which was inactivated within 5 sec. PPMS effectively eliminated rif-SI on all carriers within 30 sec. Moreover, at both concentrations, PPMS successfully inactivated AIV on all carriers within 30 sec, except on stainless steel at 0.5X. Furthermore, PPMS at both concentrations required 5 and 30 sec, respectively, to inactivate AIV on the rayon sheet. Therefore, due to its demonstrated efficacy against a wide range of pathogens across diverse surfaces, PPMS emerges as a crucial alternative disinfectant significantly enhancing biosecurity on and around chicken farms. found in and around animal farms, slaughterhouses, and hospitals.

Sepsis is a serious and life-threatening medical emergency associated with dysregulated host immune responses to infection. Like cerebral vascular or acute cardiovascular incidents, sepsis is considered a time-dependent condition having severe and long-term consequences on human health. Apart from organ support, prompt administration of appropriate antimicrobial therapy is crucial to limit the burden of complications related to sepsis in ICU patients. The management of septic patients requires comprehensive and multi-disciplinary strategies for an adequate diagnosis. Most of the ICU population receives empirical antibiotic therapy without having a confirmed diagnosis. The misuse of antibiotics in intensive care units may increase the possibility of developing multidrug resistance along with considerable ecological side effects. The first doses of empirical anti-microbial therapy are slightly higher, regardless of the presence or absence of organ dysfunction, which may upregulate the production of circulating pro-and-anti-inflammatory mediators, having negative effects on the general well-being of the patients. This notion supports the introduction of individualized antimicrobial approaches based on local patterns of resistance to ensure the appropriate dosage of empirical therapy, as well as to limit the emergence of multidrug resistance in advanced-care patients. The adequacy and treatment duration must be viewed at regular intervals for effective de-escalation, and novel diagnostic approaches must be introduced to improve the quality of care in the ICU population.

Octenidine-containing antiseptic oromucosal solution has proven to be efficacious and safe for temporary bacterial reduction and plaque inhibition in the oral cavity. While its clinical outcomes are encouraging, further research is needed to assess its microbicidal activity against pathogens causing gingivitis and periodontitis. We evaluated the in vitro microbicidal activity of different dilution concentrations of a commercially-available 0.1% octenidine dihydrochloride containing oromucosal solution (OOS) against 10 periodontopathogenic bacteria and three yeast strains using the testing methodology frameworks of DIN EN 13727:2012+A2:2015 (30-s contact time) and DIN EN 13624:2022-08 (60-s contact time), respectively. The OOS showed significant bactericidal activity at 80% dilution concentration, as indicated by a log reduction factor (lg RF) ≥5 for all 10 bacteria. At 50% dilution concentration, bactericidal activity was observed against specific bacteria like Porphyromonas gingivalis, Prevotella buccalis, Parvimonas micra, Eikenella corrodens, Dialister pneumosintes, Schaalia odontolytica (Actinomyces odontolyticus), and Campylobacter rectus. Yeasticidal activity against Candida albicans was observed at 80% dilution concentration, whereas Candida auris was more susceptible to the OOS and showed lg RF ≥4 even at 50% dilution concentration. Therefore, the OOS may be an effective adjunct to periodontal therapy aimed at reducing pathogenic microbial load, inhibiting plaque formation, and thereby preventing periodontal inflammation.

Background: Bacterial infections constantly have a large impact on public health, because of increased rates of resistance and reduced frequency of development of novel antibiotics. The utility of conventional antibiotics for treating bacterial infections has become increasingly challenging. The aim of the study was to assess the antibacterial effect of β -Lapachone, a novel synthetic compound. Methods: The antibacterial activity of the β -Lapachone compound was examined against laboratory strains by agar well diffusion method, minimal inhibitory concentration (MICs), and minimal bactericidal concentration (MBCs). Growth kinetics inhibition in presence of β -Lapachone on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa (ATCC 27853) was assessed by MABA. Crystal violet blue assay was used for biofilm inhibition assays, biofilm eradication assay and for molecular modeling PyMOL was used. Results: β -Lapachone exhibited potent antimicrobial activity against laboratory strains of bacteria with MIC of 0.2 mM for S. saprophyticus and Staphylococcus aureus, and 0.04 mM for Staphylococcus epidermidis and Pseudomonas aeruginosa ATCC 27853. The inhibition of catalase enzyme was found to be the cause for its antibacterial activity. Molecular modeling predicted the binding of β -Lap at active site and heme binding site of catalase, KatA. The activity of some commercial antibiotics was enhanced in association with β -Lap. In addition, β -Lap inhibited the biofilm formation and eradicated the already formed and ultra-mature biofilms of aforesaid bacterial strains.

Electrolyzed water, which mainly contains hypochlorous acid, is widely used because of its strong microbicidal effects, biosafety, and eco-friendliness. For frequent use in intraoral treatments, we focused on neutral electrolyzed water (NW) produced using two-stage electrolysis and investigated its storage stability. For standard-concentration NWs with free available chlorine concentration (ACC) of 25, 35, and 50 mg/L and high-concentration NWs (100, 200, 300, 500, and 1000 mg/L), changes in the pH, oxidation-reduction potential, and ACC during 126 days of storage and the bactericidal efficacies were examined. Storage under non-shaded conditions at room temperature (LRT) and a higher ACC substantially altered the properties of the NW. NW (≤ 300 mg/L) had a pH of 5.9–7.3 even after storage under LRT; however, NW with higher ACC (500 and 1000 mg/L) had a pH ˂ 5.5, critical for human enamel), even under shaded and refrigerated conditions (SLW). Only NW (25 mg/L) stored under LRT exhibited the lowest ACC (5 mg/L), indicating a decreased bactericidal effect. When stored for use in intraoral treatments, NWs should be prepared with an ACC of 25–300 mg/L and stored in SLW. If diluted NW is used, the ACC should be checked and appropriately diluted every time.

Mechanical robustness, biocompatibility, and antibacterial performances are key features for materials suitable to be used in tissue engineering applications. In this work, we investigated the link existing between structural and functional properties of TiCu(Ag) thin films deposited by physical vapor deposition magnetron sputtering on Si substrates. The thin films were characterized by X-ray diffraction (XRD), nanoindentation, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The TiCu(Ag) thin films showed complete amorphous structure and improved mechanical properties in comparison with pure Ti films. However, for contents in excess of 20% Ag, we observed the appearance of nanometric Ag crystallite. The TiCu(Ag) thin films displayed excellent biocompatibility properties, allowing adhesion and proliferation of the human fibroblasts MRC-5 cell line. Moreover, all the investigated TiCu(Ag) alloy display bactericidal properties, preventing the growth of both Pseudomonas aeruginosa and Staphylococcus aureus. Results obtained from biological tests have been correlated to the surface structure and microstructure of films. The excellent biocompatibility and bactericidal properties of these multifunctional thin films opens to their use in tissue engineering applications.

Dermatoses are essentially due to infectious or free radical aggression, immunoallergic disor-ders, or can be secondary to general diseases. To investigate new antimicrobial sources against dermatoses, Opilia amentacea crude ethanol extracts and fractions were subjected to phytochemical screening and tested for antioxidant and antimicrobial activities on Gram-positive cocci, Gram negative bacilli and fungi. Phytochemical screening revealed secondary metabolites such as sterols, triterpenes, flavonoids and tannins. Leaves and stem bark of Opilia amentacea exhibited the highest total phenolic contain (65,92 ± 0,93 and 65,71 ± 0,57 mg GAE/g DW respectivily) and flavonoids (38,8 ± 1,05 and 26,81 ± 0,19mg QE/g DW respectively). Dichloromethane fractions of leaves (FDFe) and stem bark (FDET) exhibited the best antioxidant activity with FRAP values of 741,15 and 662,84 mMol AAE/g and IC50 values of ABTS of 88,40 and 36,85 µg/mL respectively. These fractions were also the most active on Gram positive bacilli while Hexane leaves (FHFe) and hexane root bark (FHER) fractions exhibited the best antifungal activity against Candida tropicalis at MIC values of 0.23 mg/mL and 0.43 mg/mL respectively. Gram-negative bacteria were particularly resistant. This study constitutes a solid scientific basis that could justify the traditional uses of Opilia amen-tacea as an antidermatosis plant.

Bacterial infection poses a serious threat to human life due to its rapidly growing resistance to antibacterial drugs, which is a significant public health issue. This study was focused on the design and synthesis of a new series of 25 analogues bearing 5-cyano-6-oxo-4-substituted phenyl-1,6-dihydropyrimidine scaffold hybridized with different substituted benzene-sulfonamides through thioacetamide linker M1-25 via the treatment of the key intermediates 2-mercapto-6-oxo-4-phenyl-1,6-dihydropyrimidine-5-carbonitriles 1a-c with different 2-chloro-N-substituted benzene-sulfonamide derivatives 4a-e overnight at room temperature. The spectroscopic data of all the new compounds (IR, 1H-NMR, 13C-NMR, and Mass) was studied in detail to confirm their molecular structures. The antimicrobial activity of the new molecules was studied against various Gram-positive, Gram-negative, and fungal strains. All the tested compounds showed promising broad spectrum antimicrobial efficacy, especially against K. pneumoniae and P. aeruginosa, with ZOI values ranging from 15 to 30 mm. Furthermore, the most promising compounds M6, M19,M 20, and M25 were subjected to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. In addition, the anti-virulence activity of the compounds was also examined using multiple biofilm assays. The new compounds revealed promising suppressing activity of microbial biofilm formation in the examined K. pneumoniae and P. aeruginosa microbial isolates. Additional in silico ADMET studies were conducted to represent their oral bioavailability, drug-likeness characteristics, and human toxicity risks. The obtained data suggest the newly prepared pyrimidine-benzene-sulfonamide derivatives may serve as model compounds amenable for further optimization and development of new antimicrobial and antisepsis candidates.

The goal of this study was to determine the relative susceptibility of four common equine wound pathogens to ten different types of antimicrobial agents based on minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Additionally, to describe the comparison of bactericidal activity of medical grade Manuka honey, local honey, and commercial, food-grade honey to other commonly used wound dressings. The objective is to provide veterinary practitioners with comparative data on the use of a variety of antimicrobial dressings for inhibiting growth of common wound bacteria. MIC and MBC for Manuka, store, and local honeys were comparable to those of sterile gauze, sugar, and hypertonic saline. Across bacterial species, local honey proved to have more bactericidal activity when compared to Manuka and commercial, food-grade honey. The MIC and MBC for PHMB gauze and foam was consistently at a higher dilution compared to the other antimicrobials. The majority of antimicrobials exhibited stronger inhibitory and bactericidal activity against a Streptococcus zooepidemicus isolate obtained from a wound compared to other bacteria that were ATCC lab acclimated. Additional research for in-vivo applications needs to be done to see whether differences exist in effective wound management.

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.