Antibiofilm and antivirulence efficacy of Pleurotus platypus methanolic extract against Staphylococcus aureus through ROS generation and cell membrane disruption.

Multi-drug resistance is recognized as a significant worldwide public health concern in the current century. Biofilm formation further exacerbates bacterial resistance to antibacterial medications, host immunological responses, and phagocytosis, resulting in long-lasting chronic illnesses. Investigating natural resources is a very potent approach for developing alternative anti-infective medications to effectively control multi-drug resistant bacterial infections. In this study, a unique mushroom species namely Pleurotus platypus had been discovered from the Terai-Duars region of West Bengal, India. The myco-chemical profiling and preliminary chemical analysis of Pleurotus platypus methanolic extract determined the significant presence of metabolites belonging to several major chemical classes such as flavonoid, alkaloid, triterpenoid, polyphenol, benzoic acids, coumarin, flavone etc. Most intriguingly, the extract possessed effective antibacterial, antibiofilm and antivirulence properties against Staphylococcus aureus and Methicillin resistant Staphylococcus aureus, one of the most notable drug-resistant opportunistic and nosocomial pathogens. Mechanistically, the mushroom extract enhanced the production of Reactive Oxygen Species (ROS) inside the targeted bacteria, causing alterations in membrane potential, damage to the cellular membrane and further release of intracellular DNA, destined to cell death. Moreover, the methanolic extract reported the eradication of pre-existing biofilms from the urinary catheter surface, hinting towards its future application in the related field. To summarize, Pleurotus platypus methanolic extract could be an excellent alternative antibacterial and antibiofilm therapeutic candidate for the effective management of Staphylococcus infections with improved outcome.

Investigating the role of HSP90 in cancer cell phenotypic plasticity.

"What are the mechanisms driving tumor evolution under the selective pressure of chemotherapeutics?" The emerging importance of epigenetic gene regulation in cancer progression necessitates not only our understanding of which genes are potential targets but also what mechanisms are employed in targeting those genes. Understanding the mechanisms that promote the evolution of the normal genome and epigenome is central to understanding how cancer cells adapt to chemotherapy. Our previous investigations have shown that heat shock protein 90 (HSP90) has a critical role in epigenetic gene regulation through histone acetylation and phenotypic plasticity. We recently extended these results in an A549 lung cancer model to test the role of HSP90 in the plasticity of cells regarding multi-drug resistance and epithelial-to-mesenchymal transition phenotypes. HSP90 is over-expressed in multiple cancers with poor prognosis. We propose that inhibition of HSP90 results in lower phenotypic plasticity of cancer cells making them more susceptible to chemotherapeutic intervention. Here we review the context of our results in the broader field of evolution of these phenotypes.

Wastewater-based surveillance of Vibrio cholerae: Molecular insights on biofilm regulatory diguanylate cyclases, virulence factors and antibiotic resistance patterns.

Vibrio cholerae is an inherent inhabitant of aquatic ecosystems. The Indian state of West Bengal, especially the Gangetic delta region is the highest cholera affected region and is considered as the hub of Asiatic cholera. V. cholerae were isolated from publicly accessible wastewater of Midnapore, West Bengal, India. Serotyping determined all isolates to be of non-O1/non-O139 serogroups. Moderate biofilm-forming abilities were noticed in most of the isolates (74.7 %) while, high biofilm formation was recorded for only 6.3 % isolates and 19 % of isolates exhibited low/non-biofilm-forming abilities. PCR-based screening of crucial diguanylate cyclases (DGCs) involved in cyclic-di-GMP-mediated biofilm signaling was performed. cdgH and cdgM were the most abundant DGCs among 93.7 % and 91.5 % of isolates, respectively. Other important DGCs, i.e., cdgK, cdgA, cdgL, and vpvC were present in 84 %, 75.5 %, 72 % and 68 % of isolates, respectively. Besides, the non-O1/non-O139 isolates were screened for the occurrence of virulence factor encoding genes. Moreover, among these non-O1/non-O139 isolates, two strains (3.17 %) harbored both ctxA and ctxB genes, which encode the cholera toxin associated with epidemic cholera. ompU was the most prevalent virulence factor, present in 24.8 % of isolates. Other virulence factors like, zot and st were found in 4.7 % and 9.5 % of isolates. Genes encoding tcp and ace were found to be PCR-negative for the isolates. Additionally, crucial virulence factor regulators, toxT, toxR and hapR were found to be PCR-positive in all the isolates. Antibiotic resistance patterns displayed further vulnerabilities with decreased sensitivity towards commonly used antibiotics with multiple antibiotic resistance index ranging between 0.37 and 0.62. The presence of cholera toxin-encoding multi-drug resistant (MDR) V. cholerae strains in environmental settings is alarming. High occurrence of DGCs are considered to encourage further investigations to use them as alternative therapeutic targets against MDR cholera pathogen due to their unique presence in bacterial systems.

In silico vaccine design for Yersinia enterocolitica: A comprehensive approach to enhanced immunogenicity, efficacy and protection.

Yersinia enterocolitica, a foodborne pathogen, has emerged as a significant public health concern due to its increased prevalence and multidrug resistance. This study employed reverse vaccinology to identify novel vaccine candidates against Y. enterocolitica through comprehensive in silico analyses. The core genome's conserved protein translocase subunit SecY was selected as the target, and potential B-cell, MHC class I, and MHC class II epitopes were mapped. 3B-cell epitopes, 3 MHCI and 11 MHCII epitopes were acquired. A multi-epitope vaccine construct was designed by incorporating the identified epitopes, TLR4 Agonist was used as adjuvants to enhance the immunogenic response. EAAAK, CPGPG and AYY linkers were used to form a vaccine construct, followed by extensive computational evaluations. The vaccine exhibited desirable physicochemical properties, stable secondary and tertiary structures as evaluated by PDBSum and trRosetta. Moreover, favorable interactions with the human Toll-like receptor 4 (TLR4) was observed by ClusPro. Population coverage analysis estimated the vaccine's applicability across 99.74 % in diverse populations. In addition, molecular dynamics simulations and normal mode analysis confirmed the vaccine's structural stability and dynamics in a simulated biological environment. Furthermore, codon optimization and in silico cloning facilitated the evaluation of the vaccine's expression potential in E. coli and pET-28a was used a recombinant plasmid. This study provides a promising foundation for the development of an efficacious vaccine against Y. enterocolitica infections.

Successful therapy of a newborn with Stenotrophomonas maltophilia nosocomial pneumonia with cefiderocol.

Cefiderocol is a new siderophore-beta-lactam antibiotic used for the treatment of severe multidrug-resistant infections like sepsis, hospital-acquired and ventilator-associated pneumonia in adults, but there are only single reports on its use in the neonatal population. We describe the successful cefiderocol treatment of a newborn with pneumogenic sepsis due to Stenotrophomonas maltophilia.

A novel C-4-modified isotetrone acts as a potent bio-enhancer to augment the activities of anti-tuberculosis drugs against Mycobacterium tuberculosis.

Mycobacterium tuberculosis is a deadly pathogen that claims millions of lives every year. Current research focuses on finding new anti-tuberculosis drugs that are safe and effective, with lesser side effects and toxicity. One important approach is to identify bio-enhancers that can improve the effectiveness of anti-tuberculosis drugs, resulting in reduced doses and shortened treatment times. The present study investigates the use of C-4 modified isotetrones as bio-enhancers. A series of studies suggest an isotetrone, labeled as C11, inhibits growth, improves MIC, MBC and enhances the killing of M. tuberculosis H37Rv strain when used in combination with the first line and injectable anti-TB drugs in a dose-dependent manner. The combination of C11 and rifampicin also reduces the generation of spontaneous mutants against rifampicin and reaches a mutation prevention concentration (MPC) with moderate rifampicin concentrations. The identified compounds are effective against the MDR strain of M. tuberculosis and non-cytotoxic in HepG2 cells. We find that C11 induces the generation of reactive oxygen species (ROS) inside macrophages and within bacteria, resulting in better efficacy.

The antimicrobial resistance landscape of slaughterhouses in western Kenya: A microbiological case study.

Slaughterhouses may be hotspots for the transmission of antimicrobial resistant (AMR) pathogens. To obtain information on the AMR landscape in Kenyan slaughterhouses, we collected swabs of the environment, animal carcasses, and workers. Bacterial isolates were identified in 101/193 (52.3 %) samples, and most showed resistance to streptomycin (68.7 %), ampicillin (48.7 %), and tetracycline (42.5 %). Multi drug resistance was exhibited by 35/80 isolates (43.8 %; 95 % CI: 33.2-54.9 %), while Extended Spectrum Beta Lactamase was expressed in 5/80 isolates (6.3 %; 95 % CI: 2.6-14.3 %). These findings illustrate the presence of resistant bacteria throughout the slaughterhouse environment, posing a risk to workers and meat consumers and highlighting the need for an integrated surveillance system along the food chain.

Phenotypic Changes in Phage Survivors of Multidrug-Resistant Klebsiella pneumoniae.

Multidrug-resistant Klebsiella pneumoniae (MDR-KP) infections have become a major global issue in the healthcare sector. Alternative viable tactics for combating bacterial infections, such as the use of bacteriophages, can be considered. One of the major challenges in phage therapy is the emergence of phage-resistant bacteria. This study isolated bacteriophages from water and soil samples against MDR-KP isolates. Susceptible bacterial hosts were exposed to phages at different concentrations and prolonged durations of time to obtain phage-resistant survivors. Phenotypic changes such as changes in growth rates, biofilm formation ability, antibiotic sensitivity patterns, and outer membrane proteins (OMPs) profiling of the survivors were studied. Our findings indicate that the phage ØKp11 and ØKp26 survivors had reduced growth rates and biofilm formation ability, altered antibiotic sensitivity patterns, and reduced OMPs expression compared with the parent MDR-KP002 isolate. These results suggest that the alternations in the bacterial envelope result in phenotypic phage resistance among MDR bacterial isolates. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01217-6.

The Impact of Fosfomycin on Gram Negative Infections: A Comprehensive Review.

Multidrug-resistant or extended drug resistance has created havoc when it comes to patient treatment, as options are limited because of the spread of pathogens that are extensively or multidrug-resistant (MDR or XDR) and the absence of novel antibiotics that are effective against these pathogens. Physicians have therefore started using more established antibiotics such as polymyxins, tetracyclines, and aminoglycosides. Fosfomycin has just come to light as a result of the emergence of resistance to these medications since it continues to be effective against MDR and XDR bacteria that are both gram-positive and gram-negative. Fosfomycin, a bactericidal analogue of phosphoenolpyruvate that was formerly utilised as an oral medication for uncomplicated urinary tract infections, has recently attracted the interest of clinicians around the world. It may generally be a suitable therapy option for patients with highly resistant pathogenic infections, according to the advanced resistance shown by gram-negative bacteria. This review article aims to comprehensively evaluate the impact of fosfomycin on gram negative infections, highlighting its mechanism of action, pharmacokinetics, clinical efficacy, and resistance patterns.

Dual inhibition of topoisomerase II and microtubule of podophyllotoxin derivative 5p overcomes cancer multidrug resistance.

Compound 5p is a 4ß-N-substituted podophyllotoxin derivative, which exhibited potent activity toward drug-resistant K562/A02 cells and decreased MDR-1 mRNA expression. Here, we further investigated its detail mechanism and tested its antitumor activity. 5p exerted catalytic inhibition of topoisomerase IIα, and didn't show the inhibitor of topoisomerase I. 5p exhibited the inhibitory effect on microtubule polymerization. 5p showed potent anti-proliferation against breast cancer, oral squamous carcinoma, and their drug-resistant cell lines, with resistance index of 0.61 and 0.86, respectively. 5p downregulated the expression levels of P-gp in KBV200 cells and BCRP in MCF7/ADR cells in dose-dependent manner. Moreover, 5p induced KB and KBV200 cells arrest at G2/M phase by up-regulating the expression of γ-H2AX, p-Histone H3 and cyclin B1. 5p induced apoptosis and pyroptosis by increased the expression levels of cleaved-PARP, cleaved-caspase3, N-GSDME as well as LDH release in KB and KBV200 cells. In addition, 5p efficiently impaired tumor growth in KB and KBV200 xenograft mice. Conclusively, this work elucidated the dual inhibitor of topoisomerase II and microtubule of 5p and its mechanism of overcoming the multidrug resistance, indicating that 5p exerts the antitumor potentiality.

IMT-P8 potentiates Gram-positive specific antibiotics in intrinsically resistant Gram-negative bacteria.

Gram-negative bacteria (GNB) pose a major global public health challenge as they exhibit a remarkable level of resistance to antibiotics. One of the factors responsible for promoting resistance against a wide range of antibiotics is the outer membrane (OM) of Gram-negative bacteria. The OM acts as a barrier that prevents the entry of numerous antibiotics by reducing their influx (due to membrane impermeability) and enhancing their efflux (with the help of efflux pumps). Our study focuses on analyzing the effect of IMT-P8, a cell-penetrating peptide (CPP), to enhance the influx of various Gram-positive specific antibiotics in multi-drug resistant Gram-negative pathogens. In the mechanistic experiments, IMT-P8 permeabilizes the OM at the same concentrations at which it enhances the activity of various antibiotics against GNB. Cytoplasmic membrane permeabilization was also observed at these concentrations, indicating that IMT-P8 acts on both the outer and cytoplasmic membranes. IMT-P8 interferes with the intrinsic resistance mechanism of GNB and has the potential to make Gram-positive specific antibiotics effective against GNB. IMT-P8 extends the post-antibiotic effect and in combination with antibiotics shows anti-persister activity. The IMT-P8/fusidic acid combination is effective in eliminating intracellular pathogens. IMT-P8 with negligible toxicity displayed good efficacy in murine lung and thigh infection models. Based on these findings, IMT-P8 is a potential antibiotic adjuvant to treat Gram-negative bacterial infections that pose a health hazard.

Analysis of antimicrobial resistance and genetic diversity of Acinetobacter baumannii in a tertiary care hospital in Haikou City.

This study addresses the distribution and antimicrobial resistance of Acinetobacter baumannii (A. baumannii) in a medical facility in Haikou City, aiming to provide essential insights for enhancing in-hospital treatment and prevention strategies. We conducted a retrospective analysis of 513 A. baumannii isolates collected from a tertiary care hospital in Haikou between January 2018 and December 2020, focusing on their antimicrobial resistance patterns. Random Amplified Polymorphic DNA (RAPD) analysis was performed on 48 randomly selected A. baumannii strains. Using Gel-pro4.0 and NTSYSspc2.10 software, we constructed dendrograms to assess the genetic diversity of these strains. Our results indicate that males between 60 and 70 years old are particularly vulnerable to A. baumannii infections, which are most frequently detected in sputum samples, with a detection rate exceeding 70%. Alarmingly, over 50% of the isolates were identified as multi-drug resistant. The RAPD-PCR fingerprinting cluster analysis demonstrated substantial genetic diversity among the strains. Using primer OPA-02 at a 45% similarity coefficient, the strains were categorized into four groups (A-D), with group A being predominant (39 strains). high-prevalence areas like the Neurosurgery and Intensive Care Medicine Wards require enhanced surveillance and targeted interventions to manage Group C infections effectively. Additionally, the varied presence of other groups necessitates customized strategies to address the specific risks in each ward. Similarly, primer 270 at a 52% similarity coefficient classified the strains into five groups (E-I), with group E being most common (36 strains). The study highlights a concerning prevalence of antimicrobial resistance, particularly multi-drug resistance, among A. baumannii strains in the Haikou hospital. The significant genetic diversity, especially within groups A and E, underscores the need for tailored hospital treatment protocols and prevention measures. These findings contribute to the growing body of research on antimicrobial resistance, emphasizing the urgent need for effective management strategies in healthcare settings.

Epidemiological characteristics of ventilator-associated pneumonia in neurosurgery: A 10-year surveillance study in a Chinese tertiary hospital.

Background: Ventilator-associated pneumonia (VAP) is a significant and common health concern. The epidemiological landscape of VAP is poorly understood in neurosurgery patients. This study aimed to explore the epidemiology of VAP in this population and devise targeted surveillance, treatment, and control efforts. Methods: A 10-year retrospective study spanning 2011 to 2020 was performed in a large Chinese tertiary hospital. Surveillance data was collected from neurosurgical patients and analyzed to map the demographic and clinical characteristics of VAP and describe the distribution and antimicrobial resistance profile of leading pathogens. Risk factors associated with the presence of VAP were explored using boosted regression tree (BRT) models. Results: Three hundred ten VAP patients were identified. The 10-year incidence of VAP was 16.21 per 1000 ventilation days. All-cause mortality was 6.1%. The prevalence of gram-negative bacteria, fungi, and gram-positive bacteria among the 357 organisms isolated from VAP patients was 86.0%, 7.6%, and 6.4%, respectively; most were multidrug-resistant organisms. Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most common pathogens. The prevalence of carbapenem-resistant A. baumannii, P. aeruginosa, and K. pneumoniae was high and increased over time in the study period. The BRT models revealed that VAP was associated with number of days of ventilator use (relative contribution, 47.84 ± 7.25), Glasgow Coma Scale score (relative contribution, 24.72 ± 5.67), and tracheotomy (relative contribution, 21.50 ± 2.69). Conclusions: Our findings provide a better understanding of the epidemiology of VAP and its risk factors in neurosurgery patients.

Antibiotic resistance of E. coli isolates from different water sources in Mbarara, Uganda.

Escherichia coli is widely used as an indicator of recent faecal pollution of water. Most E. coli strains are commensals; however, isolates in water samples have been shown to carry antibiotic resistance determinants. In total, 47 E. coli were isolated from selected drinking water sources in Mbarara, Uganda. The isolates were examined for their susceptibility to seven antibiotics and the presence of nine antibiotic-resistance genes (mostly ß-lactamase genes) and class 1 integrons. Isolates showed a high resistance to ampicillin of 55.5% and a high sensitivity to azithromycin and gentamicin at 98 and 96%, respectively. PCR analysis showed the presence of extended-spectrum ß-lactamase genes blaCTX-M-32 and blaCMY-2 in 64 and 36% of the isolates. The carbapenemase genes blaOXA-48, blaVIM-2, blaNDM-1, and blaKPC-3 were either not detected or only in a very small number of the isolates, whereas class 1 integrons were present in 68% of the isolates. This study proves that antimicrobial resistance exists in E. coli in water used for drinking purposes in Mbarara city. There is a need for public health actors to improve the surveillance of microbiological quality of drinking water to minimize health risks.

Bacteriophage Therapy on an In Vitro Wound Model and Synergistic Effects in Combination with Beta-Lactam Antibiotics.

One of the primary opportunistic pathogens that can cause a wide range of diseases is Pseudomonas aeruginosa. This microorganism can become resistant to practically every antibacterial currently in use, including beta-lactam antibiotics. Its ability to proliferate as biofilm has been linked to, among other things, the failure of antimicrobial therapies. Due to a variety of virulence factors and host immune system modifications, P. aeruginosa is one of the most significant and common bacteria that colonize wounds and burns. A novel therapeutic option for treating these multidrug-resistant (MDR) bacterial infections is the combination of antibiotics and bacteriophages. This approach has been linked to improved biofilm penetration, a decreased selection of antibiotic and bacteriophage resistance, and an enhanced antibacterial impact. Combining the F1Pa bacteriophage and beta-lactam antibiotics reduced the viability of the mature biofilm of MDR P. aeruginosa strains and suppressed bacterial growth in vitro. F1Pa critically reduced the amount of biofilm that MDR P. aeruginosa clinical strains formed in the in vitro wound model. These findings highlight the bacteriophage F1Pa's therapeutic potential as a prophylactic topical treatment against MDR pseudomonal infections in wounds and burns.

Analysis of Antibiotic Resistance Genes (ARGs) across Diverse Bacterial Species in Shrimp Aquaculture.

There is little information available on antibiotic resistance (ABR) within shrimp aquaculture environments. The aim of this study was to investigate the presence of antibiotic resistance genes (ARGs) in shrimp farming operations in Atacames, Ecuador. Water samples (n = 162) and shrimp samples (n = 54) were collected from three shrimp farming operations. Samples were cultured and a subset of isolates that grew in the presence of ceftriaxone, a third-generation cephalosporin, were analyzed using whole-genome sequencing (WGS). Among the sequenced isolates (n = 44), 73% of the isolates contained at least one ARG and the average number of ARGs per isolate was two, with a median of 3.5 ARGs. Antibiotic resistance genes that confer resistance to the ß-lactam class of antibiotics were observed in 65% of the sequenced isolates from water (20/31) and 54% of the isolates from shrimp (7/13). We identified 61 different ARGs across the 44 sequenced isolates, which conferred resistance to nine antibiotic classes. Over half of all sequenced isolates (59%, n = 26) carried ARGs that confer resistance to more than one class of antibiotics. ARGs for certain antibiotic classes were more common, including beta-lactams (26 ARGs); aminoglycosides (11 ARGs); chloramphenicol (three ARGs); and trimethoprim (four ARGs). Sequenced isolates consisted of a diverse array of bacterial orders and species, including Escherichia coli (48%), Klebsiella pneumoniae (7%), Aeromonadales (7%), Pseudomonadales (16%), Enterobacter cloacae (2%), and Citrobacter freundii (2%). Many ARGs were shared across diverse species, underscoring the risk of horizontal gene transfer in these environments. This study indicated the widespread presence of extended-spectrum ß-lactamase (ESBL) genes in shrimp aquaculture, including blaCTX-M, blaSHV, and blaTEM genes. Increased antibiotic resistance surveillance of shrimp farms and identification of aquaculture operation-level risk factors, such as antibiotic use, will likely be important for mitigating the spread of ARGs of clinical significance.

Polyketide Synthase 13 (Pks13) Inhibition: A Potential Target for New Class of Anti-tubercular Agents.

Tuberculosis is one of the deadly infectious diseases that has resurfaced in multiple/ extensively resistant variants (MDR/XDR), threatening humankind. Today's world has a higher prevalence of tuberculosis (TB) than it has ever had throughout human history. Due to severe adverse effects, the marketed medications are not entirely effective in these forms. So, developing new drugs with a promising target is an immense necessity. Pks13 has emerged as a promising target for the mycobacterium. The concluding step of mycolic acid production involved Pks13, a crucial enzyme that helps form the precursor of mycolic acid via the Claisen-condensation reaction. It has five domains at the active site for targeting the enzyme and is used to test chemical entities for their antitubercular activity. Benzofurans, thiophenes, coumestans, N-phenyl indoles, and ß lactones are the ligands that inhibit the Pks13 enzyme, showing potential antitubercular properties.

Single Atom Engineered Antibiotics Overcome Bacterial Resistance.

The outbreak of antibiotic-resistant bacteria, or "superbugs", poses a global public health hazard due to their resilience against the most effective last-line antibiotics. Identifying potent antibacterial agents capable of evading bacterial resistance mechanisms represents the ultimate defense strategy. This study shows that -the otherwise essential micronutrient- manganese turns into a broad-spectrum potent antibiotic when coordinated with a carboxylated nitrogen-doped graphene. This antibiotic material (termed NGA-Mn) not only inhibits the growth of a wide spectrum of multidrug-resistant bacteria but also heals wounds infected by bacteria in vivo and, most importantly, effectively evades bacterial resistance development. NGA-Mn exhibits up to 25-fold higher cytocompatibility to human cells than its minimum bacterial inhibitory concentration, demonstrating its potential as a next-generation antibacterial agent. Experimental findings suggest that NGA-Mn acts on the outer side of the bacterial cell membrane via a multimolecular collective binding, blocking vital functions in both Gram-positive and Gram-negative bacteria. The results underscore the potential of single-atom engineering toward potent antibiotics, offering simultaneously a long-sought solution for evading drug resistance development while being cytocompatible to human cells.

Investigation of a linezolid-resistant Staphylococcus epidermidis outbreak in a French hospital: phenotypic, genotypic, and clinical characterization.

Purpose: We aimed to retrospectively investigate an outbreak of linezolid-resistant Staphylococcus epidermidis (LRSE), at Tours University Hospital between 2017 and 2021. Methods: Twenty of the 34 LRSE isolates were included in the study. Antimicrobial susceptibility testing was performed using the disk diffusion method and MICs of last-resort antibiotics were determined using broth microdilution or Etest®. Seventeen of the 20 resistant strains were sent to the French National Reference Centre for Staphylococci to determine the mechanism of resistance to linezolid. The clonal relationship between LRSE strains was assessed by PFGE and the sequence type determined by MLST. We retrospectively evaluated a new typing tool, IR-Biotyper®, and compared its results to PFGE to evaluate its relevance for S. epidermidis typing. Medical records were reviewed, and antibiotic consumption was determined. Search for a cross transmission was performed. Results: All LRSE strains showed high levels of resistance to linezolid (MICs ≥ 256 mg/L) and were multi-drug resistant. Linezolid resistance was associated with the 23S rRNA G2576T mutation and none of the 17 strains analyzed carried the cfr gene. Ninety-five percent of the 20 LRSE studied strains were genetically related and belonged to sequence-type ST2. The dendrogram obtained from IR-Biotyper® showed 87% congruence with the PFGE analysis. Prior to isolation of the LRSE strain, 70% of patients received linezolid. No patients stayed successively in the same room. Conclusion: Linezolid exposure may promote the survival and spread of LRSE strains. At Tours University Hospital, acquisition of the resistant clone may also have been triggered by hand-to-hand transmission by healthcare workers. In addition, IR-Biotyper® is a promising typing tool for the study of clonal outbreaks due to its low cost and short turnaround time, although further studies are needed to assess the optimal analytical parameters for routine use.

Polyvinylpyrrolidone capped silver nanoparticles enhance the autophagic clearance of Acinetobacter baumannii from human pulmonary cells.

Acinetobacter baumannii, an opportunistic pathogen has shown an upsurge in its multi-drug resistant isolates. OmpA of A. baumannii induces incomplete autophagy and apoptosis in host cells. Various therapeutic alternatives are under investigation against A. baumannii. Here, the major emphasis has been laid on comparing the efficacy of AgNP with different capping agents. OmpA targeted lead, Ivermectin capped AgNP (IVM-AgNP) has been compared with the antibacterial polyvinylpyrrolidone capped AgNP (PVP-AgNP) for their role in the modulations of host autophagy. Upregulation of p62 and LC3B confirmed by real-time PCR analysis indicated an increased autophagic flux upon the treatment with AgNPs. The elongation and closure of autophagic vacuoles was also supported by upregulated Atg genes (Atg4, Atg3, Atg5) in A. baumannii infected cells after treatment with AgNP. Autophagic flux increased on treatment with PVP-AgNP as suggested by the rise in mcherryLC3B fluorescence in A549 cells treated with PVP-AgNP as compared to the GFP-LC3B of IVM-AgNP. This suggests that PVP-AgNP treatment more effectively promotes the elongation and maturation stages of autophagy by increasing autophagic flux. These results indicate that capped AgNPs have the efficiency to revert the incomplete autophagy induced by A. baumannii back to normal autophagic levels.