Enterococci are gastrointestinal commensals whose hardiness allowed them to colonize very diverse environments, including soils, water, food and feed. This ability to overcome adverse conditions makes enterococci problematic once they colonize hospital niches. Together with the malleability of their genomes, the capacity to acquire and disseminate determinants of antibiotic resistance have contributed to convert what was once just another opportunistic pathogen into a first-class clinical problem. This review discusses the dimension of the emergence of enterococcal resistance to key antimicrobial agents, the dissemination of this resistance and its significance in terms of public health, with the aim of raising the awareness to the need to devise and implement monitoring programmes and effective antibiotic usage guidelines.

Staphylococcal bacteriophages of Kayvirus genus are candidates for therapeutic applications. One of their proteins, Tgl, is slightly similar to staphylococcal virulence factors, secreted autolysins of lytic transglycosylase motifs, IsaA and SceD. We show that Tgl is also a lytic enzyme secreted by bacterial transport system and localizes to cell peripheries, like IsaA and SceD. It caused lysis of E. coli cells expressing the cloned tgl gene, but could be overproduced when depleted of signal peptide. S. aureus cells producing Tgl lysed in the presence of nisin, which mimics the action of phage holin. In vitro, Tgl protein was able to destruct S. aureus cell walls. The production of Tgl decreased S. aureus tolerance to vancomycin, unlike the production of SceD, which is associated with the decreased sensitivity to vancomycin. In the genomes of kayviruses, the tgl gene is located a few genes away from gene lysK, encoding the major endolysin. While lysK is a late phage gene, tgl can be transcribed by a host RNA polymerase, as are phage early genes. Taken together our data indicate that tgl is a part of kayviruses lytic module and encodes an additional endolysin which can act in concert with LysK in cell lysis.

Bifidobacteria have long been recognized as bacteria with probiotic and therapeutic features. The aim of this work is to characterize the Bifidobacterium asteroides BA15 and BA17 strains, isolated from honeybee gut. An in-depth assessment was carried out on safety properties (antibiotic resistance profiling, β-haemolytic, DNAse and gelatinase activities and virulence factor presence) and other properties (antimicrobial activity, auto-aggregation, co-aggregation and hydrophobicity). Based on phenotypic and genotypic characterization, both strains satisfied all the safety requirements. More specifically, genome analysis showed the absence of genes encoding for glycopeptide (vanA, vanB, vanC-1, vanC-2, vanD, vanE, vanG), resistance to tetracycline (tet-M, tet-L and tetO), and virulence genes (asa1, gelE, cylA, esp, hyl).

Background: Disentangling adverse drug reactions from confounders remains a major challenge to assess causality and severity in neonates. Vancomycin and amikacin are perceived as nephrotoxic and often prescribed in neonates. We selected these compounds to assess their impact on creatinine dynamics as sensitive tool to detect a renal impairment signal. Methods: A recently developed dynamical model that characterized serum creatinine concentrations of 217 ELBW neonates (4036 serum creatinine observations) was enhanced with data on individual administration of vancomycin and/or amikacin to identify a potential effect of antibiotic exposure by nonlinear mixed-effects modelling analysis. Results: Of our ELBW patients, 77% were exposed to either vancomycin or amikacin. Antibiotic exposure resulted in transient lower overall creatinine clearance and a modest increase in serum creatinine. Dependency on gestational age was observed in the difference in serum creatinine when exposed to antibiotics during the third week after birth (difference in creatinine for a neonate at 24 weeks gestation decreased with 56% for a 32-week-old neonate). Conclusions: A previously described model on creatinine dynamics was used to explore and quantify the impact amikacin or vancomycin exposure on creatinine dynamics. Such tools can be used to explore minor changes, or compare minor differences between treatment modalities.

Vancomycin is one of the ‘last-line’ classes of antibiotics used in the treatment of life-threatening infections caused by Gram-positive bacteria. Even though vancomycin was discovered in 1950s it was widely used after 1980s for the treatment of infections caused by methicillin-resistant Staphylococci as prevalence of such strains were increased. However, currently it is evident that vancomycin resistant Staphylococcusaureusandvancomycin-resistant Enterococci have been developed as a result of various reasons including use of avaparcin, which is an analog of vancomycin, as feed additive in livestock. In present day context, more attention should be paid on prevention of emergence of resistance for the antibiotics in order to keep antibiotics effective. In order to prevent emergence of resistance, proper guidance for the responsible use of antimicrobials is indispensable. Therefore, almost all stakeholders who use antibiotics should have in depth understanding on the antibiotic they use. As such, it is imperative to be aware of the important aspects of vancomycin. In the present review, efforts have been made to discussthe pharmacokinetics and pharmacodynamics, indications, emergence of resistance, control of resistance, adverse effects and alternative therapy for vancomycin.

Surface modification of polypropylene (PP) films is achieved using gamma-irradiation-induced grafting to proffer with antimicrobial activity. The copolymer was obtained through a versatile two-step route; pristine PP is exposed to gamma rays and grafted using methyl methacrylate (MMA), then N-vinylimidazole (NVI) is grafted onto the copolymer PP-g-MMA by simultaneous irradiation. The characterization included Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and physicochemical analysis of swelling and contact angle. The copolymer (PP-g-MMA)-g-NVI was loaded with vancomycin, and the drug released was quantified by UV-vis spectrophotometry at different pH. The surface of (PP-g-MMA)-g-NVI exhibited pH-responsiveness and moderate hydrophilicity, suitable properties for controlled drug release.

Necrotizing pneumonia due to Methicillin-Resistant Staphylococcus Aureus (MRSA) is devastating and difficult to treat in preterm infants. We report a case of severe MRSA necrotizing pneumonia in a preterm infant. As an add-on rescue therapy to vancomycin, linezolid rapidly cured this case after the failure of vancomycin plus rifampicin. This rapid cure suggests that adjunctive rather than rescue linezolid may be considered in such cases.