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Background Environmental disinfection is essential for reducing spread of healthcare-associated infections (HAIs). Previous studies report conflicting results regarding the effects of ultraviolet (UV) light in reducing infections. This trial evaluated the impact of adding pulsed-xenon UV (PX-UV) to standard terminal cleaning in reducing environmentally implicated HAIs (eiHAIs). Methods The Lowering the Acquisition of MDROs with Pulsed-xenon (LAMP) trial was conducted in 2 hospitals (15 inpatient wards) utilizing a cluster-randomized, controlled, double-blinded, interventional crossover trial comparing standard terminal cleaning followed by either PX-UV (intervention arm) or sham (control arm) disinfection. The primary outcome was incidence of eiHAIs from clinical microbiology tests on the fourth day of stay or later or within 3 days after discharge from the study unit. EiHAIs included clinical cultures positive for vancomycin-resistant enterococci, extended-spectrum beta-lactamase–producing Escherichia coli or Klebsiella pneumonia , methicillin-resistant Staphylococcus aureus , and Acinetobacter baumannii , and stool polymerase chain reaction (PCR) positive for Clostridiodes difficile. Results Between 18 May 2017 and 7 January 2020, 25 732 patients were included, with an incidence of 601 eiHAIs and 180 954 patient-days. There was no difference in the rate of eiHAIs in the intervention and sham arms (3.49 vs 3.17 infections/1000 patient-days, respectively; RR, 1.10; 95% CI,.94–1.29; P =.23). Study results were similar when stratified by eiHAI type, hospital, and unit type. Conclusions The LAMP study failed to demonstrate an effect of the addition of UV light disinfection following terminal cleaning on reductions in rates of eiHAIs. Further investigations targeting hospital environmental surfaces and the role of no-touch technology to reduce HAIs are needed. Clinical Trials Registration. ClinicalTrials.gov identifier: NCT03349268; R01HS024709. [ABSTRACT FROM AUTHOR]

Background: Characteristics of non-clinical strains of methicillin-resistant Staphylococcus aureus (MRSA) especially from fishery environment are poorly understood. This research, in addition to comprehensive characterisation, sought to delineate the genetic relatedness between the MRSA strains originating from clinical as well as non-clinical settings. Out of 39 methicillin-resistant staphylococcal isolates from 197 fish samples, 6 (Three each of methicillin-resistant S. haemolyticus (MRSH) and MRSA) with distinct resistance profiles were selected for whole-genome sequencing. Using respective bioinformatics tools, MRSA genomes were comprehensively characterized for resistome, virulomes, molecular epidemiology and phylogenetic analysis. Simultaneously, MRSH genomes were specifically examined to characterize antimicrobial resistance genes (ARGs), owing to the fact that MRSH is often recognized as a reservoir for resistance determinants. Results: Three MRSA clones identified in this study include ST672-IVd/t13599 (sequence type-SCCmec type/spa type), ST88-V/t2526, and ST672-IVa/t1309. Though, the isolates were phenotypically vancomycin-sensitive, five of the six genomes carried vancomycin resistance genes including the VanT (VanG cluster) or VanY (VanM cluster). Among the three MRSA, only one harbored the gene encoding Panton-Valentine Leukocidin (PVL) toxin, while staphylococcal enterotoxin (SEs) genes such as sea and seb, associated with staphylococcal food poisoning were identified in two other MRSA. Genomes of MRSH carried a composite of type V staphylococcal cassette chromosome mec (SCCmec) elements (5C2 & 5). This finding may be explained by the inversion and recombination events that may facilitate the integration of type V elements to the SCC elements of S. aureus with a methicillin-susceptible phenotype. Phylogenetically, MRSA from a non-clinical setting displayed a considerable relatedness to that from clinical settings. Conclusion: This study highlights the genetic diversity and resistance profiles of MRSA and MRSH, with non-clinical MRSA showing notable relatedness to clinical strains. Future research should explore resistance gene transfer mechanisms and environmental reservoirs to better manage MRSA spread. [ABSTRACT FROM AUTHOR]

The rise of vancomycin-resistant enterococci (VRE) due to antibiotic overuse poses a significant threat to long-term care patients and those with impaired immune systems. Therefore, it is imperative to seek alternatives to overcome multidrug resistance. This study aimed to evaluate totarol, a natural compound derived from Podocarpus totara, for its antibacterial activity against vancomycin-resistant Enterococcus faecalis (VREF). Totarol exhibited potent antibacterial activity at a very low concentration of 0.25 µg/mL and demonstrated antibiofilm effects through biofilm inhibitory concentration and biofilm eradication concentration assays. Confocal laser scanning microscopy confirmed that totarol inhibited not only biofilm mass but also bacterial cell viability. The combinatorial use of sublethal concentrations of totarol and vancomycin showed antibacterial activity, as observed in the time-kill assay. Quantitative polymerase chain reaction assays revealed a concentration-dependent downregulation of key virulence genes (vanA, ace, asa, efaA, and esp) in VREF when exposed to totarol. In summary, totarol emerges as a promising adjuvant with vancomycin for inhibiting VREF, addressing vancomycin resistance and biofilm formation—critical challenges associated with VRE infection. Since this was an in vitro study, the role of totarol in the clinical implications of VREF treatment remains to be demonstrated. [ABSTRACT FROM AUTHOR]

Introduction: Enterococci are commensals of the gastrointestinal tract of humans and animals that evolved into opportunistic pathogens with high antimicrobial resistance and virulence. Multidrug-resistant Enterococcus is a major cause of hospital-acquired infections worldwide. For this reason, the characterization of non-clinical reservoirs of Enterococci and their epidemiological link to resistant hospital isolates is crucial for controlling their spread. Methods: A total of 295 samples collected from livestock (pigs and cows, n = 135) and environment (public buses, passengers hands, and urban environments, n = 160) were screened for Enterococcus spp. E. faecium antimicrobial resistance profiles, virulence potential, and clonal population were further characterized. Results: Enterococci were detected in 90.5% (n = 267) of the samples, with a higher prevalence in livestock (100%) than the environment (82.5%, p < 0.0001), but none of the isolates exhibited vancomycin resistance. E. faecalis was the most prevalent species (51.7%), predominantly found in livestock (62.2%), while E. faecium was more common in the environment. Of the 59 E. faecium isolates, 78% showed resistance to =3 antibiotic classes and contained associated resistance genes, namely tetracyclines (tetM and tetL), beta-lactams (mutations in pbp5), and high-level resistance to aminoglycosides (ant(6)-Ia and aac(6')-aph(2)). A wide array of virulence factors was detected among E. faecium, associated with adherence, biofilm formation, and adaptation to host response, while hospitalassociated virulence markers, such as IS16, were less frequent, probably due to the non-clinical nature of the isolates. Clonal population analysis revealed a diverse E. faecium population. Although no direct epidemiological link could be traced between our isolates and specific clinical isolates, infection-associated genetic backgrounds were identified in non-clinical isolates: one isolate from pigs belonged to CC17 (ST32), while four isolates belonged to CC94, including one recovered from pigs (ST296), one from cows (ST2206), one from the urban environment (ST1205), and other from buses (ST800). Discussion: This study underscores a high prevalence of clinically relevant Enterococcus species among healthy livestock and the environment. Despite the absence of vancomycin resistance and limited hospital infection-associated clonal lineages, the presence of E. faecium with significant virulence potential and resistance to critical antibiotics in human and veterinary medicine highlights the need for continuing surveillance of non-clinical reservoirs. [ABSTRACT FROM AUTHOR]

Background: Clostridium innocuum, previously considered a commensal microbe, is a spore-forming anaerobic bacterium. C. innocuum displays inherent resistance to vancomycin and is associated with extra-intestinal infections, antibiotic-associated diarrhea, and inflammatory bowel disease. This study seeks to establish a multilocus sequence typing (MLST) scheme to explore the correlation between C. innocuum genotyping and its potential pathogenic phenotypes. Methods: Fifty-two C. innocuum isolates from Linkou Chang Gung Memorial Hospital (CGMH) in Taiwan and 60 sequence-available C. innocuum isolates from the National Center for Biotechnolgy Information Genome Database were included. The concentrated sequence of housekeeping genes in C. innocuum was determined by amplicon sequencing and used for MLST and phylogenetic analyses. The biofilm production activity of the C. innocuum isolates was determined by crystal violet staining. Results: Of the 112 C. innocuum isolates, 58 sequence types were identified. Maximum likelihood estimation categorized 52 CGMH isolates into two phylogenetic clades. These isolates were found to be biofilm producers, with isolates in clade I exhibiting significantly higher biofilm production than isolates in clade II. The sub-inhibitory concentration of vancomycin seemed to minimally influence biofilm production by C. innocuum isolates. Nevertheless, C. innocuum embedded in the biofilm structure demonstrated resistance to vancomycin treatments at a concentration greater than 256 µg/mL. Conclusions: This study suggests that a specific genetic clade of C. innocuum produces a substantial amount of biofilm. Furthermore, this phenotype assists C. innocuum in resisting high concentrations of vancomycin, which may potentially play undefined roles in C. innocuum pathogenesis. [ABSTRACT FROM AUTHOR]

Background: The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains resistant to non-beta-lactam antimicrobials poses a significant challenge in treating severe MRSA bloodstream infections. This study explores resistance development and mechanisms in MRSA isolates, especially after the first dalbavancin-resistant MRSA strain in our hospital in 2016. Methods: This study investigated 55 MRSA bloodstream isolates (02/2015–02/2021) from the University Hospital of the Medical University of Vienna, Austria. The MICs of dalbavancin, linezolid, and daptomycin were assessed. Two isolates (16–33 and 19–362) resistant to dalbavancin were analyzed via whole-genome sequencing, with morphology evaluated using transmission electron microscopy (TEM). Results: S.aureus BSI strain 19–362 had two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene. Isolate 16–33 had a 534 bp deletion in the DHH domain of GdpP and a SNV in pbp2 (p.G146R). Both strains had mutations in the rpoB gene, but at different positions. TEM revealed significantly thicker cell walls in 16–33 (p < 0.05) compared to 19–362 and dalbavancin-susceptible strains. None of the MRSA isolates showed resistance to linezolid or daptomycin. Conclusion: In light of increasing vancomycin resistance reports, continuous surveillance is essential to comprehend the molecular mechanisms of resistance in alternative MRSA treatment options. In this work, two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene were newly identified as possible causes of dalbavancin resistance. [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this study was to investigate the effect of sheep lymph nodes and antibiotics on the bacterium that causes acne and the bacteria that usually exist with it. Materials and Methods: In this laboratory study, 24 patients with acne (18 to 45 years old) were selected to isolate the bacteria. Also, 24 clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis were isolated from the wound samples of patients. After culturing the bacteria, their sensitivity to common antibiotics was evaluated. Data were reported as percentage. Results: The results showed that Cutibacterium acnes and Staphylococcus aureus were 100% sensitive to vancomycin. Also, Cutibacterium acnes showed sensitivity in tetracycline and imipenem groups in 95% of cases and in cotrimoxazole and piperacillin/tazobactam groups in 90% of cases. In addition, the highest sensitivity of Staphylococcus epidermis to piperacillin/tazobactam (62.5%) and the highest drug resistance (91.67%) were related to azithromycin and erythromycin groups. Conclusion: Due to the increase in drug resistance, it is suggested to use antibiotics with the least drug resistance such as vancomycin and imipenem in the treatment of acne. [ABSTRACT FROM AUTHOR]

Aims In Tunisia, limited research has focused on characterizing clinical vancomycin-resistant Enterococcus faecium (VREfm). This study aimed to bridge this knowledge gap by molecular characterization of antimicrobial resistance, determining the genetic elements mediating vancomycin-resistance, and whole-genome sequencing of one representative VREfm isolate Methods and results Over 6 years (2011–2016), a total of eighty VREfm isolates responsible for infection or colonization were identified from hospitalized patients, with the incidence rate increasing from 2% in 2011 to 27% in 2016. All of these strains harbored the vanA gene. The screening for antimicrobial resistance genes revealed the predominance of ermB, tetM , and aac(6′)-Ie-aph(2′')-Ia genes and 81.2% of strains harbored the Tn 1545. Pulsed-field gel electrophoresis identified seven clusters, with two major clusters (belonging to ST117 and ST80) persisting throughout the study period. Seven Tn 1546 types were detected, with type VI (truncated transposon) being the most prevalent (57.5%). Whole-genome sequencing revealed a 3 028 373 bp chromosome and five plasmids. Mobile genetic elements and a type I CRISPR-cas locus were identified. Notably, the vanA gene was carried by the classic Tn 1546 transposon with ISL3 insertion on a rep17pRUM plasmid. Conclusion A concerning trend in the prevalence of VREfm essentially attributed to CC17 persistence and to horizontal transfer of multiple genetic variants of truncated vanA -Tn 1546. [ABSTRACT FROM AUTHOR]

Vancomycin-resistant Enterococci (VREs) have increasingly become a major nosocomial pathogen worldwide. The increasing prevalence of vancomycin-resistant enterococci (VRE) in hospitals poses a serious threat to patients due to their multiple drug resistance. This study aimed to determine the prevalence of vancomycin resistance among the various Enterococcal species isolated from clinical samples, Methods: A Total of 150 enterococcus species isolated from different clinical samples were subjected to vancomycin-resistant enterococcus (VRE) screening using conventional microbiological methods. Antibiotic susceptibility testing of allenterococcalisolates and screening and confirmatory tests were performed to detect specific resistance mechanisms. Minimum inhibitory concentrations (MIC) of vancomycin were determined using the microdilution method. Results: out of 150 enterococcus species isolated from different clinical samples were subjected to vancomycin resistance using conventional microbiological methods. The incidence rate of male VRE was 7/11 (63.6%), and female VRE was 4/11 (34.4%). Most VREs were from male patients of different age groups. Of these, 7 were E. faecalis& 4 were E. faecium. Conclusion: Enterococci have emerged as a pathogen associated with severe nosocomial infections &E. faecalis and E. faecium cause most clinical infections. [ABSTRACT FROM AUTHOR]

This review uses the total synthesis of vancomycin analogues by Boger and his colleagues as a case study of the drug discovery process. Vancomycin is a glycopeptide antibiotic used to treat staphylococcal infections. It acts by binding to the terminal chains attached to peptidoglycan in bacterial cell walls, which blocks these chains from crosslinking with each other. This inability to crosslink prevents the bacterium from forming a cell wall, ultimately resulting in bacterial cell death. However, over time, bacteria have evolved resistance to vancomycin. In response to this, Boger and his team studied single atom changes (O, S, NH) in the chemical structure of vancomycin to create new vancomycin analogues that these bacteria are not resistant to. The drug discovery process involves upstream and downstream flow of information about a potential drug candidate, and the interlude of Boger's work with vancomycin elegantly demonstrates this process. Boger found that replacing a single oxygen atom in vancomycin with NH significantly increases the ability of the analogue to bind with peptidoglycan terminal chains, increasing its effectiveness as an antibiotic. [ABSTRACT FROM AUTHOR]

This study aimed to determine the ESKAPE antimicrobial resistance patterns and associated factors with multi-drug resistance strains among hospitalized patients in a single tertiary care medical hospital in Palestine. Methods: A single-center retrospective cross-sectional study was conducted by reviewing patients' electronic medical records and laboratory results from November 1, 2021, to November 30, 2022, at the Palestine Medical Complex in Palestine. The study included patients aged > 18 years who had been infected with ESKAPE pathogens 48 hours after hospital admission. Results: This study included 231 patients, of whom 90.5% had MDR infections. In total, 331 clinical samples of ESKAPE pathogens were identified. A. baumannii was the most prevalent MDR pathogen (95.6%) with Carbapenem-resistant exceeding 95%, followed by K. pneumoniae (83.8%) with extended-spectrum cephalosporin resistance exceeding 90%, S. aureus (68.2) with 85% oxacillin-resistance, E. faecium (40%) with 20% vancomycin resistance, P. aeruginosa (22.6%) with 30% carbapenem resistance. Furthermore, emergent colistin resistance has been observed in A. baumannii, K. pneumoniae, and P. aerogenesis. Risk factors for MDR infection included age (p< 0.035), department (p< 0.001), and invasive procedures such as IUC (p< 0.001), CVC (p< 0.000), and MV (p< 0.008). Patients diagnosed with MDR bacteria had increased 30-day mortality (p< 0.001). Conclusion: The findings of this study show alarming MDR among hospitalized patients infected with ESKAPE pathogens, with resistance to first-line antimicrobial agents and emerging resistance to colistin, minimizing treatment options. Healthcare providers and the Ministry of Health must take steps, adopt policies to prevent antimicrobial resistance, adhere to infection control guidelines, implement antimicrobial stewardship programs to prevent and limit the growing health crisis, and support research to discover new treatment options. [ABSTRACT FROM AUTHOR]

Vancomycin-resistant Enterococcus faecium (VRE) has been detected in Türkiye. Only limited information is available on its dissemination in the central regions of the country. This study describes the first epidemiological characterization of VRE clinical isolates detected in patients in a hospital in the province of Aksaray. In this one-year study conducted between 2021 and 2022, stool samples from intensive care unit patients were screened for VRE using the phenotypic E-test method, and the antibiotic sensitivity test was analyzed by using the VITEK® 2 system. A molecular assay for confirmation of species level was carried out by 16S rRNA gene-based sequencing and testing for antibiotic resistance (vanA or vanB) and virulence factor-encoding genes (esp, asa1, and hyl). Further, genotypic characterization was determined by macro-restriction fragment pattern analysis (MRFPA) of genomic DNA digested with SmaI restriction enzyme. Of the total 350 Enterococcus positive patients from different hospital intensive care units, 22 (6.3%) were positive for VRE using the phenotypic E-test method. All isolates showed resistance to ampicillin, ciprofloxacin, vancomycin, and teicoplanin and positive amplification for the vanA gene. However, none of the isolates was positive for the vanB gene. The most prevalent virulence gene was esp. The results indicate that the isolates are persistent in the hospital environment and subsequently transmitted to hospitalized patients, thus representing challenges to an outbreak and infection control. These study results would also help formulate more effective strategies to reduce the transmission and propagation of VRE contamination in various hospital settings. [ABSTRACT FROM AUTHOR]

Vancomycin variable Enterococcus (VVE) bacteria are phenotypically susceptible to vancomycin, but they harbor the vanA gene. We aimed to ascertain the prevalence of VVE among clinically isolated vancomycin-susceptible Enterococcus faecium (VSE) isolates, as well as elucidate the molecular characteristics of the vanA gene cluster within these isolates. Notably, we investigated the prevalence and structure of the vanA gene cluster of VVE. Between June 2021 and May 2022, we collected consecutive, non-duplicated vancomycin-susceptible Enterococcus faecium (VSE) samples. Real-time PCR was performed to detect the presence of vanA, vanB, and vanC. Overlapping PCR with sequencing and whole -genome sequencing were performed for structural analysis. Sequence types (STs) were determined by multilocus sequence typing. Exposure testing was performed to assess the ability of the isolates to acquire vancomycin resistance. Among 282 VSE isolates tested, 20 isolates (7.1%) were VVE. Among them, 17 isolates had partial deletions in the IS1216 or IS1542 sequences in vanS (N=10), vanR (N=5), or vanH (N=2). All VVE isolates belonged to the CC17 complex and comprised five STs, namely ST17 (40.0%), ST1421 (25.0%), ST80 (25.0%), ST787 (5.0%), and ST981 (5.0%). Most isolates were related to three hospital-associated clones (ST17, ST1421, and ST80). After vancomycin exposure, 18 of the 20 VVEs acquired vancomycin resistance. Considering the high reversion rate, detecting VVE by screening VSE for vanA is critical for appropriate treatment and infection control. [ABSTRACT FROM AUTHOR]

As an emerging environmental contaminant, antibiotic resistance genes (ARGs) in tap water have attracted great attention. Although studies have provided ARG profiles in tap water, research on their abundance levels, composition characteristics, and potential threat is still insufficient. Here, 9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China. Additionally, 75 sets of environmental sample data (9 types) were downloaded from the public database. Metagenomics was then performed to explore the differences in the abundance and composition of ARGs. 221 ARG subtypes consisting of 17 types were detected in tap water. Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs, their composition varied. In tap water samples, the three most abundant classes of resistance genes were multidrug, fosfomycin and MLS (macrolide-lincosamide-streptogramin) ARGs, and their corresponding subtypes ompR, fosX and macB were also the most abundant ARG subtypes. Regarding the potential mobility, vanS had the highest abundance on plasmids and viruses, but the absence of key genes rendered resistance to vancomycin ineffective. Generally, the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline. Although the current potential threat to human health posed by ARGs in tap water is limited, with persistent transfer and accumulation, especially in pathogens, the potential danger to human health posed by ARGs should not be ignored. [ABSTRACT FROM AUTHOR]

Objectives: We analysed 4 y of laboratory data to characterise the species and determine the antimicrobial susceptibility profiles of enterococci as human pathogens in Fiji. The study also investigated the molecular epidemiology amongst the subset of vancomycin-resistant enterococci (VRE). Methods: This retrospective study reviewed bacteriological data from Colonial War Memorial Hospital (CWMH) and other healthcare facilities in the Central and Eastern divisions of Fiji. Phenotypic, antimicrobial susceptibility and vanA and vanB PCR testing were performed using locally approved protocols. The first clinical isolates per patient with antimicrobial susceptibility testing results in a single year were included in the analysis. Data was analysed using WHONET software and Microsoft Excel. Results: A total of 1817 enterococcal isolates were reported, 1415 from CWMH and 402 from other healthcare facilities. The majority of isolates, 75% (n = 1362) were reported as undifferentiated Enterococcus spp., 17.8% (n = 324) were specifically identified as Enterococcus faecalis and 6.7% (n = 122) as E. faecium. Overall, 10% of the enterococci isolates were from blood cultures. Among isolates from CWMH,

Vancomycin has proven remarkably durable to resistance evolution by Staphylococcus aureus despite widespread treatment with vancomycin in the clinic. Only 16 cases of vancomycin-resistant S. aureus (VRSA) have been documented in the United States. It is thought that the failure of VRSA to spread is partly due to the fitness cost imposed by the vanA operon, which is the only known means of high-level resistance. Here, we show that the fitness cost of vanA-mediated resistance can be overcome through laboratory evolution of VRSA in the presence of vancomycin. Adaptation to vancomycin imposed a tradeoff such that fitness in the presence of vancomycin increased, while fitness in its absence decreased in evolved lineages. Comparing the genomes of vancomycin-exposed and vancomycin-unexposed lineages pinpointed the D-alanine:D-alanine ligase gene (ddl) as the target of loss-of-function mutations, which were associated with the observed fitness tradeoff. Vancomycin-exposed lineages exhibited vancomycin dependence and abnormal colony morphology in the absence of drug, which were associated with mutations in ddl. However, further evolution of vancomycin-exposed lineages in the absence of vancomycin enabled some evolved lineages to escape this fitness tradeoff. Many vancomycin-exposed lineages maintained resistance in the absence of vancomycin, unlike their ancestral VRSA strains. These results indicate that VRSA might be able to compensate for the fitness deficit associated with vanA-mediated resistance, which may pose a threat to the prolonged durability of vancomycin in the clinic. Our results also suggest vancomycin treatment should be immediately discontinued in patients after VRSA is identified to mitigate potential adaptations. Author summary: The clinical utility of antibiotics is threatened by the potential evolution of resistance in the pathogen being targeted. Thus, we seek to understand why some antibiotics effectively evade the evolution of resistance. Vancomycin has remained one of the few effective antibiotics in the treatment of methicillin-resistant Staphylococcus aureus (MRSA), with few cases of vancomycin-resistant S. aureus (VRSA) being reported. However, the basis of vancomycin's durability and the ability of VRSA to further adapt to vancomycin in the laboratory has yet to be investigated. Herein, we describe the evolutionary trajectories of several laboratory-propagated VRSA strains. We show that VRSA can overcome the fitness cost imposed by vancomycin resistance, a result which threatens the long-term use of vancomycin in the clinic. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is an important human pathogen, for which there are very limited treatment options, primarily the glycopeptide antibiotic vancomycin. In recent years, vancomycin resistance has emerged as a serious problem in several gram-positive pathogens, but high-level resistance has yet to be reported for C. difficile, although it is not known if this is due to constraints upon resistance evolution in this species. Here, we show that resistance to vancomycin can evolve rapidly under ramping selection but is accompanied by fitness costs and pleiotropic trade-offs, including sporulation defects that would be expected to severely impact transmission. We identified 2 distinct pathways to resistance, both of which are predicted to result in changes to the muropeptide terminal D-Ala-D-Ala that is the primary target of vancomycin. One of these pathways involves a previously uncharacterised D,D-carboxypeptidase, expression of which is controlled by a dedicated two-component signal transduction system. Our findings suggest that while C. difficile is capable of evolving high-level vancomycin resistance, this outcome may be limited clinically due to pleiotropic effects on key pathogenicity traits. Moreover, our data identify potential mutational routes to resistance that should be considered in genomic surveillance. Clostridioides difficile is a human pathogen primarily treated with the antibiotic vancomycin. High-level vancomycin resistance is a serious problem in other pathogens, not yet for C. difficile. This study identifies two resistance pathways in C. difficile, which evolve rapidly but with fitness costs that could affect transmission. [ABSTRACT FROM AUTHOR]

Background: Enterococcus gallinarum (EG) is typically found in the gastrointestinal tracts of birds and mammals. Although its strains are rarely isolated from clinical specimens, EG can lead to septicemia in immunocompromised individuals. EG infections are uncommon in household settings, but their incidence has been rising due to increased antibiotic usage and invasive treatments, particularly in Neonatal Intensive Care Units (NICUs). EG inherently exhibits resistance to vancomycin but is highly sensitive to linezolid. Despite showing in vitro resistance, vancomycin has shown clinical efficacy in treating EG meningitis. Case presentation: A neonate born at 30 + 2 weeks gestation was admitted to the Neonatal Intensive Care Unit (NICU) after EG was detected in blood and cerebrospinal fluid cultures. Susceptibility testing indicated that the bacterial strain was resistant to vancomycin and sensitive to linezolid. Initially, vancomycin was selected for treatment. However, due to persistent EG cultures in the blood and cerebrospinal fluid, the treatment was adjusted to linezolid. This led to a rapid decrease in platelet (PLT) count, suspected to be an adverse reaction. Concurrently, the patient experienced recurrent fever and elevated inflammatory marker levels, prompting the discontinuation of linezolid and a return to vancomycin. Subsequent administration of vancomycin stabilized the patient's condition, as evidenced by improved C-reactive protein (CRP), procalcitonin (PCT), and cerebrospinal fluid parameters, ultimately leading to discharge after an eight-week treatment period. Conclusion: This retrospective analysis highlights the efficacy of vancomycin in treating EG infections, suggesting that specific genetic phenotypes may influence treatment sensitivity. Monitoring vancomycin blood levels is crucial for determining treatment effectiveness. [ABSTRACT FROM AUTHOR]

Aims To investigate enterococci carrying linezolid and vancomycin resistance genes from fecal samples recovered from wild boars Methods and results Florfenicol- and vancomycin-resistant enterococci, isolated on selective agar plates, were screened by PCR for the presence of linezolid and vancomycin resistance genes. Five isolates carried optrA or poxtA linezolid resistance genes; one strain was resistant to vancomycin for the presence of vanA gene. All isolates were tested for their antibiotic susceptibility and subjected to Whole Genome Sequencing (WGS) analysis. In Enterococcus faecalis (E. faecalis) V1344 and V1676, the optrA was located on the new pV1344-optrA and pV1676-optrA plasmids, respectively, whereas in Enterococcus faecium (E. faecium) V1339 this gene was on a 22 354-bp chromosomal genetic context identical to the one detected in a human E. faecium isolate. In both E. faecium V1682 and E. durans V1343, poxtA was on the p1818-c plasmid previously found in a human E. faecium isolate. In E. faecium V1328, the vanA gene was on the Tn 1546 transposon in turn located on a new pV1328-vanA plasmid. Only E. faecium V1682 successfully transferred the poxtA gene to an enterococcal recipient in filter mating assays. Conclusions The occurrence of genetic elements carrying linezolid and vancomycin resistance genes in enterococci from wild boars is a matter of concern, moreover, the sharing of plasmids and transposons between isolates from wild animals, human, and environment indicates an exchange of genetic material between these settings. [ABSTRACT FROM AUTHOR]

Introduction: The human gut microbiome harbors millions of bacterial species, including opportunistic pathogens, and this microbial community is exposed to antimicrobial agents present in food, the external environment, or drugs. Thus, it increases the risk of commensals being enriched with resistant genes, which may get even transmitted to opportunistic pathogens often with the help of mobile genetic elements. There is limited information about the current burden of resistant genes in the healthy gut microbiome of the Indian population, the latter is not only the largest in the world but is also periodically monitored for the prevalence of antibiotic resistance in clinical samples. Methods: We analyzed publicly available fecal whole-metagenome shotgun sequencing data from 141 samples from three healthy Indian cohorts for antimicrobial-resistance burden, and their likely transmission modes. Results: The overall resistance profile showed a higher number of resistance genes against tetracycline, glycopeptide, and aminoglycoside. Out of a total of 188 antimicrobial resistance genes identified in all cohorts, moderately to highly prevalent ones could potentially target seven of the 'reserve' group antibiotics (colistin, fosfomycin, Polymyxin). We also observed that geographical location affected the prevalence/abundance of some of the resistance genes. The higher abundance of several tetracycline and vancomycin resistance genes in tribal cohorts compared to the other two urban locations was intriguing. Species E. coli had the highest number of resistant genes, and given its relatively modest abundance in gut microbiomes can pose a risk of becoming a hub for the horizontal transfer of resistance genes to others. Lastly, a subset of the resistance genes showed association with several types of mobile genetic elements, which potentially could facilitate their transmission within the gut community. Discussion: This is a first systematic report on AMR genes in healthy gut microbiome samples from multiple locations of India. While trends for several of the prevalent AMR genes showed similarity with global data, but a few population specific trends need further attention by policy-makers. The association of AMR genes with mobile elements may pose a risk for transmission to other gut bacteria. [ABSTRACT FROM AUTHOR]

Background. In this study, attempts were made to evaluate the frequency of high‐level gentamicin‐resistant (HLGR) and vancomycin‐resistant enterococci (VRE) and the prevalence and antibiotic resistance profile of enterococcal species isolated from pediatric patients referred to Children's Medical Center Hospital, Tehran, over five years. Materials and Methods. A total of 404 enterococcal isolates from different patients referred to the Children's Medical Center between March 2016 and March 2021 were included in this cross‐sectional study. Antimicrobial susceptibility testing was performed using standard methods according to the guidelines of the Clinical Laboratories Standards Institute (CLSI). Results. Approximately one‐third of the enterococcal strains were isolated from urology and intensive care units. 17.3% of the isolates were obtained from outpatient sources. However, 82.7% of the isolates were sourced from inpatient settings. We found that the rates of resistance to ampicillin, penicillin, and vancomycin were twice as high in inpatients as in outpatients. Of the total isolates, 87.4% and 49.3% were identified as HLGR and VRE, respectively. In addition, we identified 2% of the VRE isolates that were not susceptible to linezolid. Nitrofurantoin showed excellent activity against enterococcal isolates in the urine, with a susceptibility rate of 92.5%. Conclusion. The present study reports the highest range of VRE isolated from pediatric patients in Iran. Despite the predominance of HLGR enterococci in our region, vancomycin remains effective against such strains. This study is among the few to demonstrate the incidence of linezolid‐insensitive VRE in pediatric patients. Therefore, it is important to evaluate effective infection control measures to prevent linezolid and vancomycin resistance in enterococci. [ABSTRACT FROM AUTHOR]

Background Epidemiologic studies have shown decreasing vancomycin susceptibility among clinical Clostridioides difficile isolates, but the impact on patient outcomes is unknown. We hypothesized that reduced vancomycin susceptibility would be associated with decreased rates of sustained clinical response (SCR). Methods This multicenter cohort study included adults with C. difficile infection (CDI) treated with oral vancomycin between 2016 and 2021. Clostridioides difficile isolates underwent agar dilution vancomycin susceptibility testing, ribotyping, and Sanger sequencing of the vancomycin resistance vanR gene. Reduced susceptibility was defined as vancomycin minimum inhibitory concentration (MIC) >2 μg/mL. The primary outcome was 30-day SCR; secondary outcomes were 14-day initial cure, 30-day recurrence, and 30-day mortality. Exploratory analysis assessed the association between the VanR Thr115Ala polymorphism, susceptibility, and outcomes. Results A high proportion (34% [102/300]) of C. difficile isolates exhibited reduced vancomycin susceptibility (range, 0.5–16 μg/mL; MIC50/90 = 2/4 μg/mL). Ribotype 027 accounted for the highest proportion (77.4% [41/53]) of isolates with reduced vancomycin susceptibility. Overall, 83% (249) of patients achieved 30-day SCR. Reduced vancomycin susceptibility was associated with lower rates of 30-day SCR (76% [78/102]) than vancomycin-susceptible strains (86% [171/198]; P =.031). A significantly lower rate of 14-day initial cure was also observed among individuals infected with strains with reduced vancomycin susceptibility (89% vs 96%; P =.04). Reduced susceptibility remained an independent predictor of 30-day SCR in multivariable modeling (odds ratio, 0.52 [95% confidence interval,.28–.97]; P =.04). Conclusions Reduced vancomycin susceptibility in C. difficile was associated with decreased odds of 30-day SCR and lower 14-day initial cure rates in the studied patient cohort. [ABSTRACT FROM AUTHOR]

Neutrophils are critical immune cells in severe coronavirus disease 2019 (COVID-19). S100 calcium-binding protein A12 (S100A12) is highly expressed in neutrophils during acute inflammation. The aim of this study was to evaluate serum S100A12 levels as a diagnostic and prognostic tool in COVID-19. Serum samples of patients with moderate and severe COVID-19 were collected during 2020 to 2024. Enzyme-linked immunosorbent assay was used to measure serum S100A12 levels in 63 patients with moderate COVID-19, 60 patients with severe disease and 33 healthy controls. Serum S100A12 levels were elevated in moderate COVID-19 compared to controls and were even higher in severe cases. In moderate disease, serum S100A12 levels positively correlated with immune cell counts. While C-reactive protein and procalcitonin are established inflammation markers, they did not correlate with serum S100A12 levels in either patient cohort. Patients with severe COVID-19 and vancomycin-resistant enterococcus (VRE) infection had increased S100A12 levels. Elevated S100A12 levels were also observed in patients with herpes simplex reactivation. Fungal superinfections did not alter S100A12 levels. These data show that serum S100A12 increases in moderate and severe COVID-19 and is further elevated by VRE bloodstream infection and herpes simplex reactivation. Therefore, S100A12 may serve as a novel biomarker for severe COVID-19 and an early diagnostic indicator for bacterial and viral infections. [ABSTRACT FROM AUTHOR]

Background The glycopeptide vancomycin is the antimicrobial agent-of-choice for the treatment of severe non-gastrointestinal infections with members of Bacillus cereus sensu lato (s.l.). Recently, sporadic detection of vancomycin-resistant phenotypes emerged, mostly for agar diffusion testing such as the disc diffusion method or gradient test (e.g. Etest®) method. Results In this work, we were able to disprove a preliminarily assumed high resistance to vancomycin in an isolate of B. cereus s.l. using broth microdilution and agar dilution. Microscopic imaging during vancomycin susceptibility testing showed spreading towards the inhibition zone, which strongly suggested sliding motility. Furthermore, transcriptomic analysis using RNA-Seq on the nanopore platform revealed several key genes of biofilm formation (e.g. calY , tasA , krsEABC) to be up-regulated in pseudo-resistant cells, substantiating that bacterial sliding is responsible for the observed mobility. Down-regulation of virulence (e.g. hblABCD , nheABC , plcR) and flagellar genes compared with swarming cells also confirmed the non-swarming phenotype of the pseudo-resistant isolate. Conclusions The results highlight an insufficiency of agar diffusion testing for vancomycin susceptibility in the B. cereus group, and reference methods like broth microdilution are strongly recommended. As currently no guideline mentions interfering phenotypes in antimicrobial susceptibility testing of B. cereus s.l. , this knowledge is essential to obtain reliable results on vancomycin susceptibility. In addition, this is the first report of sliding motility undermining accurate antimicrobial susceptibility testing in B. cereus s.l. and may serve as a basis for future studies on bacterial motility in susceptibility testing and its potential impact on treatment efficacy. [ABSTRACT FROM AUTHOR]

Introduction: Since its discovery in 1961, methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as a significant healthcare-associated pathogen (HA-MRSA) and a notorious 'superbug'. Typing is crucial for surveillance, epidemiology analysis, infection control of MRSA and sequencing of the spa gene is one of the most common methods used for determining the origin of this bacterium in humans and animals. This research aimed to determine the antibiotic resistance and spa type of S. aureus strains collected from outpatients in two hospitals in the Wasit province of Iraq. Material & Methods: The study analyzed 200 outpatient MRSA isolates by collecting nasal and sputum samples from patients. Standard biochemical and molecular methods based on the nuc gene were used to identify S. aureus bacteria and amplify the mecA and spa genes. The Kirby-Bauer disc diffusion method was employed to determine the antibiotic sensitivity of the isolates using penicillin, cefoxitin, vancomycin, gentamicin, erythromycin, tetracycline, imipenem, clindamycin, chloramphenicol and rifampicin. Results: Methods. The prevalence of MRSA was more common in women than in men. Antibiogram results showed that most of the isolates were resistant to penicillin (94.2%) and sensitive to imipenem (100%), clindamycin (100%), and chloramphenicol (100%). Of these 35 isolates, 30 (87.5%) and 26 strains (74.3%) were positive for the mecA and spa genes. Typing based on spa gene sequencing revealed four different patterns: t386, t3579, U0002 and U0234. Conclusion: Variations in the spa gene among different S. aureus isolates may he of clinical importance when treating staphylococcal infections. In this study, spa typing revealed four different patterns in Iraq, representing diagnostic and therapeutic implications. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is a major global health problem, and, among Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) represents a serious threat. MRSA causes a wide range of infections, including bacteremia, which, due to the limited use of β-lactams, is difficult to treat. This study aimed to analyze 51 MRSA isolates collected in 2018 from samples of patients with bacteremia from two hospitals of the Metropolitan Health Service of Santiago, Chile, both in their resistance profile and in the identification of virulence factors. In addition, genomic characterization was carried out by the WGS of an isolate that was shown to be the one of greatest concern (N°. 42) due to its intermediate resistance to vancomycin, multiple virulence factors and being classified as ST8 PVL-positive. In our study, most of the isolates turned out to be multidrug-resistant, but there are still therapeutic options, such as tetracycline, rifampicin, chloramphenicol and vancomycin, which are currently used for MRSA infections; however, 18% were PVL positive, which suggests greater virulence of these isolates. It was determined that isolate N°42 is grouped within the USA300-LV strains (ST8, PVL+, COMER+); however, it has been suggested that, in Chile, a complete displacement of the PVL-negative ST5 clone has not occurred. [ABSTRACT FROM AUTHOR]

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Enterococci commonly cause nosocomial bloodstream infections (BSIs), and the global incidence of vancomycin-resistant enterococci (VRE) BSIs is rising. This study aimed to assess the risk factors for enterococcal BSIs and 30-day mortality, stratified by Enterococcus species, vancomycin resistance, and treatment appropriateness. We conducted a retrospective cohort study (2014–2021) including all hospitalized adult patients with at least one blood culture positive for Enterococcus faecalis or Enterococcus faecium. We included 584 patients with enterococcal BSI: 93 were attributed to vancomycin-resistant E. faecium. The overall 30-day mortality was 27.5%; higher in cases of BSI due to vancomycin-resistant E. faecium (36.6%) and vancomycin-sensitive E. faecium (31.8%) compared to E. faecalis BSIs (23.2%) (p = 0.016). This result was confirmed by multivariable Cox analysis. Independent predictors of increased mortality included the PITT score, complicated bacteremia, and age (HR = 1.269, p < 0.001; HR = 1.818, p < 0.001; HR = 1.022, p = 0.005, respectively). Conversely, male gender, consultation with infectious disease (ID) specialists, and appropriate treatment were associated with reduced mortality (HR = 0.666, p = 0.014; HR = 0.504, p < 0.001; HR = 0.682, p = 0.026, respectively). In conclusion, vancomycin-resistant E. faecium bacteremia is independently associated with a higher risk of 30-day mortality. [ABSTRACT FROM AUTHOR]

Boza, a cereal‐based beverage popular in southeast Europe, is fortified with probiotics and is believed to positively impact the composition of the gut microflora. This investigation focused on fermented cereal‐based beverage boza to identify strains of probiotic Lactobacillus spp. capable of inhibiting carbohydrate‐hydrolysing enzymes α‐glucosidase (AG) and α‐amylase (AA). The isolated bacterial strains underwent a comprehensive assessment, including biochemical, molecular, and probiotic trait analyses such as tolerance survivability, adhesion, safety, and health‐promoting attributes. We evaluated the inhibitory potential of the supernatant, cell lysate, and intact cells of Lactobacillus spp. Molecular analysis has revealed that isolates RAMULAB30 and RAMULAB29 exhibit a significant genetic similarity (>97%) to Lacticaseibacillus paracasei and Limosilactobacillus fermentum, respectively. These findings are documented in the NCBI database. They exhibited significant resistance to gastrointestinal and intestinal fluids, also indicating their potential for adhesion. Additionally, the isolates showed a significant antibacterial activity, particularly against Micrococcus luteus. They showed resistance to vancomycin and methicillin antibiotics but were more susceptible to streptomycin and ampicillin. Furthermore, the strains demonstrated antioxidant properties. To ensure their safety, a haemolytic assay was conducted despite their general recognition as safe (GRAS) status. The study primarily aimed to evaluate the inhibitory effects of the extract on enzymes AG and AA. Bacterial isolates demonstrated a significant inhibitory activity against both enzyme AG (32%–67% inhibition) and enzyme AA (18%–46% inhibition) in different forms, including supernatant (CS), lysed extract (CE), and intact cell (IC). These findings underscore the potential of bacterial isolates to inhibit the enzyme activity effectively. Furthermore, the L. fermentum RAMULAB29 and L. paracasei RAMULAB30 strains exhibit remarkable antidiabetic potential. Food products incorporating these strains have promising prospects as nutraceuticals, providing improved health benefits. [ABSTRACT FROM AUTHOR]

The dipeptide D‐Ala‐D‐Ala is an essential component of peptidoglycan and the target of vancomycin. Most Clostridioides difficile strains possess the vanG operon responsible for the synthesis of D‐Ala‐D‐Ser, which can replace D‐Ala‐D‐Ala in peptidoglycan. The C. difficile vanG operon is regulated by a two‐component system, VanRS, but is not induced sufficiently by vancomycin to confer resistance to this antibiotic. Surprisingly, in the absence of the VanS histidine kinase (HK), the vanG operon is still induced by vancomycin and also by another antibiotic, ramoplanin, in a VanR‐dependent manner. This suggested the cross‐regulation of VanR by another HK or kinases that are activated in the presence of certain lipid II‐targeting antibiotics. We identified these HKs as CD35990 and CD22880. However, mutations in either or both HKs did not affect the regulation of the vanG operon in wild‐type cells suggesting that intact VanS prevents the cross‐activation of VanR by non‐cognate HKs. Overproduction of VanR in the absence of VanS, CD35990, and CD22880 led to high expression of the vanG operon indicating that VanR can potentially utilize at least one more phosphate donor for its activation. Candidate targets of CD35990‐ and CD22880‐mediated regulation in the presence of vancomycin or ramoplanin were identified by RNA‐Seq. [ABSTRACT FROM AUTHOR]

Vancomycin-resistant Staphylococcus aureus (VRSA), a "high priority antibiotic-resistant pathogen", is emerging and threatening global health. Nevertheless, molecular mechanisms associated with virulence and multidrug resistance in VRSA are not fully investigated particularly in low- and middle-income countries. Here, for the first time, the complete genome of a VRSA strain VR480 isolated from a Vietnamese patient was generated by the combination of long- and short-read sequencing technologies. The VRSA strain VR480 was a multidrug-resistant phenotype with resistance to at least one antibiotic belonging to beta lactams, quinolones, lincomycin, oxazolidinones, tetracyclines, glycylcyclines, macrolide/lincosamide/streptogramin, nitrofurans, rifamycins, sulfonamides and glycopeptides. This strain was classified as vancomycin resistance (MIC ≥ 32 μg/mL). VRSA strain VR480 belonged to sequence type ST2779 and carried the SCCmec type II(2A). The VRSA strain VR480 genome contains five resistance mutations in genes. gyrA S84L, parC S80F, parE D432N, fusA L461K and glpT W355Stop, and eleven antibiotic resistant genes including mecA, mecR, mecI, tetM, tet38, mepA, lmrS, ant(9), ermA, fosB and catA. This strain possesses various virulence factors associated with adherence, biofilm formation, colonization, invasion, anti-phagocytosis and toxicity that promote the infection and pathogenesis. Protein interaction network analysis revealed five clusters consisting of known and putative virulence proteins. Furthermore, epimerase, EssC, IcaA, SplA and Ssl1 were the key proteins within each cluster. This study raises a warning about the circulation and dissemination of VRSA in Vietnam. The key proteins would be potential targets for the development of anti-virulent agents to combat the VRSA infection. [ABSTRACT FROM AUTHOR]

Background: Enterococcus, a low virulent yet hardy organism, is a cause of many community acquired as well as nosocomial infections. Antibiotic resistance in Enterococcus spp. is rising worldwide owing to their intrinsic resistance to multiple drugs. The combination therapy of betalactam antibiotics with aminoglycosides is the choice of treatment for this type of infection. But this is often rendered ineffective on account of high-level aminoglycoside resistance. Vancomycin resistance further complicates the scenario. Objectives: To note the predominant infections caused by Enterococcus spp. and to show their resistance pattern, with particular emphasis on vancomycin resistance. Materials and methods: This study was conducted retrospectively in our tertiary care teaching hospital in Odisha, Eastern India, where 200 consecutive, nonrepetitive Enterococcus spp obtained on culture were included. Their demographic profile was collected from the lab register, and analysis was done using MS Excel. Results: The commonest sample from which Enterococcus spp was isolated was urine (n = 82, 41%), followed by blood (n = 49, 24.5%). E. faecalis (n = 120, 60 %) followed by E. faecium (n = 55, 27.5 %) were the most common species seen. Flouroquinolones, macrolides, and tetracycline were the most resistant antibiotics for all the Enterococcus species. E. faecalis had a much higher percentage of susceptibility to penicillin and higher level gentamicin (76.5% and 55.6%, respectively) compared to E. faecium (10.7% and 13.2%, respectively). Among the total, 43 (21.5%) isolates were vancomycin resistant, and only 3 (1.5%) showed moderate susceptibility. All the isolates 200 (100%) were tigecycline susceptible. Conclusion: The present study highlights increased vancomycin resistance as noted in 21.5% Enterococcus isolates. Quinolones, macrolides, and tetracycline showed better sensitivity to vancomycin resistant Enterococcus, probably owing to lesser use in clinical scenarios. Urinary tract infection is the predominant infection caused by Enterococcus spp. Nitrofurantoin is an effective drug, particularly for E. faecalis. [ABSTRACT FROM AUTHOR]

Objective: Staphylococcus aureus (S. aureus) is a zooanthroponotic, nosocomial, and community-associated pathogen that threatens livestock management and even public health. The goal of this investigation was to clarify the role of S. aureus in zoonotic illnesses. Besides that, a novel trial was conducted in the current Egyptian study using oil extracts such as cactus oil, tea oil, geranium oil, and thyme oil to demonstrate the susceptibility of methicillin-resistant S. aureus (MRSA) isolates to these organic oils in response to the alarming global concern regarding the decreased susceptibility of S. aureus to known antibiotics, which exacerbates control and treatment protocols. Material and Methods: A total of 110 samples (45 raw cattle milk samples, 35 Karish cheese samples, and 30 human sputum samples) were collected. The bacterium was identified via traditional culturing methods, Gram staining, and the application of several biochemical tests. After that, various kinds of known commercial antibiotics were used to detect the antimicrobial susceptibility (AMS) of the obtained isolates. Furthermore, conventional polymerase chain reaction (PCR) testing was performed to identify S. aureus (nuc gene) and MRSA (mecA gene), with further application of multiplex PCR for screening of all the obtained isolates for vancomycin resistance via targeting vanA, vanB, and vanC genes. Finally, the agar gel diffusion method was performed to assess the antibacterial activity of four plant extracts (cactus oil, tea oil, geranium oil, and thyme oil) against the obtained MRSA. Results: The culturing method revealed S. aureus positivity in raw cattle milk (13.33%), in Karish cheese (28.57%), and in human samples (20%). The obtained isolates showed mainly resistance to amoxicillin-clavulanic and ampicillin antibiotics, while the dairy samples showed further resistance against ceptaxime and an intermediate reaction against erythromycin. On the molecular side, PCR positivity was present in human samples (10%), raw cow milk (13.33%), and Karish cheese (14.29%). Nine of the fourteen PCR isolates were methicillin-resistant S. aureus (MRSA) isolates. Comparing the four oil extracts against the acquired MRSA isolates, cactus oil extract proved to be the most effective. Conclusion: The study's results are highly promising as they support the notion that certain essential oils possess strong antimicrobial properties against zoonotic S. aureus, thereby reducing the excessive use of antibiotics in veterinary and medical settings. [ABSTRACT FROM AUTHOR]

Cellulosimicrobium species (formerly known as Oerskovia) are Gram-positive filamentous bacteria in the family Promicromonosporaceae and are more commonly found in sewage and soil. The present study aimed to identify all the published cases of Cellulosimicrobium species infections in the literature, describe the epidemiological, clinical, and microbiological characteristics, and provide data regarding its antimicrobial resistance, treatment, and outcomes. A narrative review was performed based on a PubMed and Scopus database search. In total, 38 studies provided data on 40 patients with infections by these species. The median age of patients was 52.5 years, and 55% were male. The most common infection types were bacteremia, infective endocarditis (IE), osteoarticular infections, peritoneal dialysis-associated peritonitis, and endophthalmitis. Antimicrobial resistance to vancomycin and the combination of trimethoprim and sulfamethoxazole was minimal, and vancomycin was the most commonly used antimicrobial for treating these infections. Overall mortality was minimal for all infections, except for bacteremia and IE, which carried high mortality rates. [ABSTRACT FROM AUTHOR]

Background and Objective: Enterococci are typically found in a healthy human gastrointestinal tract but can cause severe infections in immunocompromised patients. Such infections are treated with antibiotics. This study addresses the rising concern of antimicrobial resistance (AMR) in Enterococci, focusing on the prevalence of vancomycin-resistant enterococcus (VRE) strains. Materials and Methods: The pilot study involved 140 Enterococci isolates collected between 2021 and 2022 from two multidisciplinary hospitals (with and without local therapeutic drug monitoring protocol of vancomycin) in Latvia. Microbiological assays and whole genome sequencing were used. AMR gene prevalence with resistance profiles were determined and the genetic relationship and outbreak evaluation were made by applying core genome multi-locus sequence typing (cgMLST). Results: The acquired genes and mutations were responsible for resistance against 10 antimicrobial classes, including 25.0% of isolates expressing resistance to vancomycin, predominantly of the vanB type. Genetic diversity among E. faecalis and E. faecium isolates was observed and seven potential outbreak clusters were identified, three of them containing sequence types ST6, ST78 and ST80. The prevalence of vancomycin resistance was highest in the hospital without a therapeutic drug-monitoring protocol and in E. faecium. Notably, a case of linezolid resistance due to a mutation was documented. Conclusions: The study illustrates the concerning prevalence of multidrug-resistant Enterococci in Latvian hospitals, showcasing the rather widespread occurrence of vancomycin-resistant strains. This highlights the urgency of implementing efficient infection control mechanisms and the need for continuous VRE surveillance in Latvia to define the scope and pattern of the problem, influencing clinical decision making and planning further preventative measures. [ABSTRACT FROM AUTHOR]

Background: Antibiotic resistance is a global public health concern that has been exacerbated by the overuse and misuse of antibiotics, leading to the emergence of resistant bacteria. The gut microbiota, often influenced by antibiotic usage, plays a crucial role in overall health. Therefore, this study aimed to investigate the prevalence of antibiotic resistant genes in the gut microbiota of Indonesian coastal and highland populations, as well as to identify vancomycin-resistant bacteria and their resistant genes. Methods: Stool samples were collected from 22 individuals residing in Pacet, Mojokerto, and Kenjeran, Surabaya Indonesia in 2022. The read count of antibiotic resistant genes was analyzed in the collected samples, and the bacterium concentration was counted by plating on the antibiotic-containing agar plate. Vancomycin-resistant strains were further isolated, and the presence of vancomycin-resistant genes was detected using a multiplex polymerase chain reaction (PCR).Results: The antibiotic resistant genes for tetracycline, aminoglycosides, macrolides, beta-lactams, and vancomycin were found in high frequency in all stool samples (100%) of the gut microbiota. Meanwhile, those meant for chloramphenicol and sulfonamides were found in 86% and 16% of the samples, respectively. Notably, vancomycin-resistant genes were found in 16 intrinsically resistant Gram-negative bacterial strains. Among the detected vancomycin-resistant genes, vanG was the most prevalent (27.3%), while vanA was the least prevalent (4.5%). Conclusion: The presence of multiple vancomycin resistance genes in intrinsically resistant Gram-negative bacterial strains demonstrated the importance of the gut microbiota as a reservoir and hub for the horizontal transfer of antibiotic resistant genes.

Urinary tract infections (UTIs) are common urological diseases that easily relapse and have led to an increasing economic and health burdens. The China Antimicrobial Surveillance Network (CHINET) system is one of the most influential antimicrobial resistance surveillance networks in China. This study analyzed antimicrobial resistance and distribution trends of uropathogens from 2015 to 2021 using the CHINET system. A total of 261,893 non-duplicate strains were collected; Gram-positive bacteria accounted for 23.8% while Gram-negative bacteria accounted for 76.2%. Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, and Enterococcus faecalis were the most common species. The resistance to vancomycin, linezolid, and teicoplanin in E. faecalis and E. faecium was less than 3%. The prevalence of carbapenem-resistant strains of E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii was 1.7%, 18.5%, 16.4%, and 40.3%, respectively. The prevalence of carbapenem-resistant A. baumannii increased from 27.6% in 2015 to 43.4% in 2021. The prevalence of methicillin-resistant Staphylococcus aureus decreased from 40.6% in 2015 to 22.9% in 2021. The resistance rates to most β-lactam antimicrobials, aminoglycosides and fluoroquinolones in E. coli, K. pneumoniae, P. aeruginosa and A. baumannii isolated from ICU inpatients were significantly higher than in those isolated from outpatients and non-ICU inpatients. This study indicates that E. coli, Enterococcus, and K. pneumoniae were the most commonly isolated uropathogens in China. The bacterial species isolated and their antimicrobial resistance patterns differed in different patient populations. More attention must be paid uropathogen resistance surveillance to provide data for the rational use of antimicrobial agents. [ABSTRACT FROM AUTHOR]

Background: Collection of bile aspirate during endoscopic retrograde cholangiopancreatography (ERCP) is essential to identify pathogens responsible for acute cholangitis. Limited data are available on the risk factors for the presence of multidrug‐resistant organisms (MDRO) in bile. Methods: We conducted this retrospective, single‐center study to assess the prevalence and susceptibility rates of bacteria in bile cultures, and the risk factors for the presence of pathogens, MDRO, and fungi in bile. All consecutive patients who underwent biliary drainage for acute cholangitis from January 2017 to December 2019 were included. Results: 443/1610 ERCPs were performed for acute cholangitis. Bile culture was collected in 91.4% (405/443), of which 86.7% were positive. Most common isolates were Enterococcus faecalis (37.6%) and Escherichia coli (32.8%). Vancomycin resistance was found in 9.9% of Enterococcus species (spp.); extended‐spectrum beta‐lactamases (ESBL) and carbapenemases in 11.2% and 0.9% of Enterobacteriaceae, respectively. The empiric antimicrobial therapy was changed in 26.4% (n = 107) of cases, with a clinical response in 90.7%. In multivariate analysis, biliary stenting was an independent risk factor for positive bile culture (odds ratio [OR] 9.43; P < 0.01). Independent risk factors for MDRO in bile were patient age>60 years (OR 2.51; P = 0.03), previous sphincterotomy (OR 2.57; P = 0.02), and biliary stenting (OR 2.80; P < 0.01). Previous sphincterotomy was the only risk factor for isolation of fungi in bile (OR 1.61; P = 0.04). Conclusions: Our study showed an increasing prevalence of Enterococcus spp. and MDRO. Bile cultures should be routinely collected in cholangitis and in patients with repeated ERCPs to allow more efficient antimicrobial treatment. [ABSTRACT FROM AUTHOR]

Low-energy N+ implantation mutagenesis allows Staphylococcus aureus to develop resistance to vancomycin. Then the vancomycin-resistant S. aureus strain was examined using drug-resistance phenotypes, and biofilm growth analysis to explore the potential resistance mechanism underlying the vancomycin-resistant S. aureus strain. The results showed that 9 vancomycin-resistant S. aureus strains were constructed by low energy N+ implantation mutagenesis. The biofilm biomass and density as well as the matrix protein content within the biofilms of five representative vancomycin-resistant strains with muti-drug resistance capacity were significantly enhanced over the original strain, and their resistance to vancomycin increased by between two and four times. These vancomycin-resistant strains acquired multiple resistance to different antibiotics. The results indicate that the enhancement of biofilm formation ability and the matrix protein content within the biofilm might be attributed to be the changes in the expression of drug-resistant-related genes in vancomycin-resistant S. aureus strains, which were mediated by low energy N+ implantation, thereby accelerating the formation of drug resistance. These results provide the theoretical basis for examining the mechanism of environmental radiation-mediating the drug-resistant formation in S. aureus. [ABSTRACT FROM AUTHOR]

The present study involves the precise identification and safety evaluation of Enterococcus casseliflavus KB1733, previously identified using 16S rRNA analysis, through whole-genome sequencing, phenotypic analysis, and preclinical toxicity studies. Analyses based on the genome sequencing data confirm the identity of KB1733 as E. casseliflavus and show that the genes related to vancomycin resistance are only present on the chromosome, while no virulence factor genes are present on the chromosome or plasmid. Phenotypic analyses of antibiotic resistance and hemolytic activity also indicated no safety concerns. A bacterial reverse mutation test showed there was no increase in revertant colonies of heat-killed KB1733. An acute toxicity test employing heat-killed KB1733 at a dose of 2000 mg/kg body weight in rats resulted in no deaths and no weight gain or other abnormalities in the general condition of the animals, with renal depression foci and renal cysts only occurring at the same frequency as in the control. Taking the background data into consideration, the effects on the kidneys observed in the current study were not caused by KB1733. Our findings suggest that KB1733 is non-pathogenic to humans/animals, although further studies involving repeated oral toxicity tests and/or clinical tests are required. [ABSTRACT FROM AUTHOR]

Today, methicillin-resistant S. aureus (MRSA) isolates are widely spread in both communities and hospitals, causing high morbidity and mortality worldwide. However, the emergence of vancomycin resistance among MRSA isolates has been perceived as a formidable threat to therapeutic management. Therefore, the present study aimed to determine the frequency and antibiotic susceptibility of MRSA and vancomycin-resistant S. aureus (VRSA) strains in Kerman hospitals in Iran. A total of 455 human clinical samples were collected from Kerman hospitals. The samples were examined for the presence of S. aureus and the isolates were tested for their susceptibility to antibiotics by disk diffusion method. MRSA and VRSA isolates were detected by a combination of phenotypic and genotypic methods. Sixty-five coagulase-positive S. aureus strains were isolated, and the higher isolation rate was from wound samples (47.7%) compared with blood (18.5%), respiratory tract secretions (10.8%), urine (10.8%), body fluids (9.2%), abscess (1.5%), and cerebrospinal fluids (1.5%). The isolates exhibited high resistance toward tetracycline (69.2%). Thirty-four isolates (52.3%) were categorized as MRSA (phenotypically resistant to cefoxitin). mecA gene was amplified in 97.1% of MRSA strains. Moreover, only one MRSA strain was resistant to vancomycin (MIC=128), and this isolate carried the vanA gene. The frequency of MRSA was not significantly associated with gender, age, sample type, and sampling locality (p>0.05). Given the alarming rate of resistance among MRSA isolates, monitoring of antibiotic resistance should be performed to reduce treatment failure in patients with staphylococcal infections. Although vancomycin remains a drug of choice for MRSA, our study suggests that its efficacy may be limited by resistance development. [ABSTRACT FROM AUTHOR]

Enterococci are part of the natural flora of the gastrointestinal tract of mammals, including humans, birds and invertebrates. They can cause infection, mainly among hospitalized patients, as well as acquire and transfer antimicrobial resistance genes. The present study allowed the isolation of 98 Enterococcus (73.47% E. faecium, 23.47% E. faecalis, 3.06% E. avium) strains from 120-day-old healthy chickens that had never been treated with antimicrobials. Their antimicrobial resistance was evaluated by the agar disk diffusion method; high-level aminoglycoside (streptomycin and gentamicin) and vancomycin resistance were established using the microbroth dilution method. The highest percentages of resistant isolates were detected with quinupristin–dalfopristin (88.78%), rifampicin (64.29%), tetracyclines (45.92%), and enrofloxacin (41.84%). High percentages of susceptible strains were found with teicoplanin (100%), amoxicillin–clavulanic acid (97.96%), nitrofurantoin (94.90%), ampicillin (92.86%), chloramphenicol (90.82%), and linezolid (88.78%). About 60% of the strains were classified as MDR (multidrug-resistant). Moreover, PCR was carried out to investigate genes encoding for tetracyclines resistance determinants: tet(M), tet(L), tet(O), tet(K), and Int-Tn. Genes were detected in 68 (69.38%) strains: 36 were shown to be resistant with the agar disk diffusion method, while 28 were intermediate, and 2 were susceptible. The present study showed that chickens never treated with antimicrobials potentially harbor enterococci having phenotypic and genotypic characters of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Manure from food-producing animals, rich in antibiotic-resistant bacteria and antibiotic resistance genes (ARGs), poses significant environmental and healthcare risks. Despite global efforts, most manure is not adequately processed before use on fields, escalating the spread of antimicrobial resistance. This study examined how different cattle manure treatments, including composting and storage, affect its microbiome and resistome. The changes occurring in the microbiome and resistome of the treated manure samples were compared with those of raw samples by high-throughput qPCR for ARGs tracking and sequencing of the V3–V4 variable region of the 16S rRNA gene to indicate bacterial community composition. We identified 203 ARGs and mobile genetic elements (MGEs) in raw manure. Post-treatment reduced these to 76 in composted and 51 in stored samples. Notably, beta-lactam, cross-resistance to macrolides, lincosamides and streptogramin B (MLSB), and vancomycin resistance genes decreased, while genes linked to MGEs, integrons, and sulfonamide resistance increased after composting. Overall, total resistance gene abundance significantly dropped with both treatments. During composting, the relative abundance of genes was lower midway than at the end. Moreover, higher biodiversity was observed in samples after composting than storage. Our current research shows that both composting and storage effectively reduce ARGs in cattle manure. However, it is challenging to determine which method is superior, as different groups of resistance genes react differently to each treatment, even though a notable overall reduction in ARGs is observed. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to determine the resistance profile of linezolid-resistant Enterococcus faecium (LREfm) and to investigate risk factors and outcomes associated with LREfm infections. Material and methods: A prospective case-control study was undertaken (2019 to 2022) and included 202 patients with LREfm infections (cases) and 200 controls with LSEfm infections. Clinical data was prospectively collected and analysed for risk factors and outcomes. Antimicrobial susceptibility was performed, and resistance profile was studied using WHOnet. Results: Risk factors associated with LREfm infection were site of infection UTI (OR 5.87, 95% CI 2.59–13.29, p ≤ 0.001), prior use of carbapenem (OR 2.85 95% CI 1.62–5.02, p ≤ 0.001) and linezolid (OR 10.13, 95% CI 4.13–24.82, p ≤ 0.001), use of central line (OR 5.54, 95% CI 2.35–13.09, p ≤ 0.001), urinary catheter (OR 0.29, 95% CI 0.12–0.70, p ≤ 0.001) and ventilation (OR 14.87, 95% CI 7.86–28.11, p ≤ 0.007). The hospital stay 8–14 days (< 0.001) prior to infection and the mortality rate (p = 0.003) were also significantly high among patients with LREfm infections. Linezolid and vancomycin resistance coexisted; further, MDR, XDR and PDR phenotypes were significantly higher among LREfm. Conclusion: This study provided insight into epidemiology of MDR LREfm in a setting where linezolid use is high. The main drivers of infections with LREfm are multiple, including use of carbapenems and linezolid. Invasive procedures and increased hospital stay facilitate spread through breach in infection control practises. As therapeutic options are limited, ongoing surveillance of LREfm and VRE is critical to guide appropriate use of linezolid and infection control policies. [ABSTRACT FROM AUTHOR]

The study screened the occurrence of VanA,VanB,Vanc genes in Staph aureus vancomycin-resistant isolates recovered in Hilla -hospitals. From various clinical samples, 160 isolates from patients between July and November of 2022 were included in the search. Among these samples are (65) burn samples, (55) urine samples, and (40) samples from Blood. 40 (or 25%) of the 160 isolates were Staph aureus. Characterization of the VanA, VanB, and VanC genes in Staph aureus isolates obtained from various specimens is the main goal of the work. The RESULTS of samples were obtained from a variety of clinical specimens, including 20 (40.625%) burn swabs, 10 (25%) urine samples, and 10 (34.375%) blood. Staph aureus was resistant to Cefepime (91.7%), Piperacillin (73.3%), and Ceftazidime (71.7%), although little relationship was detected with Aztreonam resistance (35%). 40 isolates were used for antibiotic sensitivity test (AST). Only 18.3% and 15% of isolates, respectively, were resistant to meropenem and imipenem. Fluoroquinolone resistance to lomefloxacin, ciprofloxacin, ofloxacin, and levofloxacin was 51.7%, 48.3%, 35%), and 30%, respectively. While the most prevalent vancomycin resistance genes were found in 40 isolates of S. aureus and were discovered by VanC 40 (100%), VanA 20 (100%), and VanB28 (70%), according to the current investigation.In Conclusion :The PCR-reaction method was discovered to be an easy-to- use tool for detecting staph aureus by pcr that can be regularly used for identifying staph aureus and detection the molecular resistance apparatuses to vancomycin in staph aureus by VanA, VanB, VanC), efflux systems plays To choose the best antibiotics, prevent the establishment of resistant strains, and create novel antimicrobial. medications, it is beneficial to research the particular resistance mechanisms vancomycin to staph aureus. [ABSTRACT FROM AUTHOR]

Vancomycin is the cornerstone in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. However, therapeutic failures can occur when MRSA strains with decreased susceptibility to glycopeptides (DSG) are involved. The aim of this study was to detect and characterize DSG in MRSA recovered from children with invasive diseases at a reference pediatric hospital between 2009 and 2019. Fifty-two MRSA strains were screened using agar plates with vancomycin 3 and 4 mg/L (BHI-3 and BHI-4); the VITEK2 system; and standard and macro E-tests. Suspicious hVISA were studied by population analysis profiling–area under the curve (PAP-AUC), and wall thickness was analyzed by transmission electron microscopy. Neither VRSA nor VISA were detected in this set. As only three strains met the hVISA criteria, the PAP-AUC study included 12 additional MRSA strains that grew one colony on BHI-4 plates or showed minimum inhibitory concentrations of vancomycin and/or teicoplanin ≥ 1.5 mg/L. One strain was confirmed as hVISA by PAP-AUC. The wall thickness was greater than the vancomycin-susceptible control strain; it belonged to ST30 and carried SCCmec IV. As expected, a low frequency of hVISA was found (1.9%). The only hVISA confirmed by PAP-AUC was not detected by the screening methods, highlighting the challenge that its detection represents for microbiology laboratories. [ABSTRACT FROM AUTHOR]

Introduction: Enterococci are major cause of health care associated infections and are resistant to commonly used antibiotics like cephalosporins. The study aims to find the proportion and characteristics of Enterococcus faecium isolates among the enterococcal infections at a tertiary care hospital. Methods and Material: A prospective cohort study was conducted in a tertiary care hospital in Mangalore, Karnataka for a period of 6 months from June to November 2023. The enterococci were isolated and identified and tested for antibiotic susceptibility by the standard methods. Results: Among the 132 enterococcal strains isolated from the clinical samples, 68 (51.51%) were E. faecalis and 61(46.21%) were E. faecium. E. faecium was significantly isolated more from the urine samples and from the inpatients. Also, the resistance to ampicillin (57.4% vs 14.7%), high level gentamicin (54.1% vs 36.8%), nitrofurantoin (37.7% vs 8.8%) and vancomycin (11.5% vs 1.5%) was significantly more among the E. faecium isolates, compared to the E. faecalis isolates. Resistance to linezolid was not found in the current study. Conclusion: In the present study, E. faecium strains were isolated in higher proportion compared to other studies. Therefore, there is an emergent need to combat this increase in E. faecium infections and the associated antibiotic resistance by scrutinising and encouraging appropriate antibiotic use in the hospitals and community. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify glycopeptide resistance genes and virulence factors in vancomycin-resistant Enterococcus species and to investigate the influence of the microbiota and hospital environment on glycopeptide resistance. Materials and Methods: A total of 107 enterococcal isolates were collected from patients' rectal swab cultures and environmental samples taken for surveillance purposes. Multiplex Polymerase Chain Reaction (PCR) analysis was conducted to investigate specific virulence genes (esp, hyl, asa1, cyl, and galE) and glycopeptide resistance genes (vanA, vanB, van C1-C2, van D, vanE, and vanG). Additionally, perirectal swab cultures were obtained from patients without vancomycin-resistant enterococcal colonization to investigate the presence of glycopeptide resistance genes in their microbiota. Results: Seven isolates (6.5%) were identified as infectious agents. The most common vancomycin resistance genes were vanA (23.3%), followed by vanA + vanB (14%) and vanB + vanD (14%), respectively. The Random Amplified Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR) method showed that patient surveillance and environmental isolates were clonally related. Moreover, microbiota analysis of patients without vancomycin-resistant enterococcal colonization revealed Clostridium spp. in two patients and Lactobacillus spp. in one patient, with the vanG gene found in the microbiota of only one (2.5%) patient. Conclusion: The detection of genes responsible for dissemination indicates that colonized isolates also have the potential for infection, and the hospital environment plays a primary role in the acquisition of vancomycin-resistant enterococci. [ABSTRACT FROM AUTHOR]

The human body hosts complex communities of microorganisms, collectively known as the "microbiota," predominantly in the lower intestine. This microbiota, which consists of bacteria, viruses, and fungi, plays a vital role in the breakdown of various nutrients and maintenance of homeostasis. The microbiome, which represents the collective genetic content of these microorganisms, is intricately associated with human health and disease. Healthcare-associated infections (HCAIs), a major public health problem, contribute to high morbidity and mortality. Exposure to antibiotics, a primary risk factor for diseases, disrupts the microbiota and compromises its protective role. Age-related changes in the microbiota affect the onset and progression of various diseases by affecting the functional capacity and fitness of the host. Inanimate surfaces in built environments contribute to HCAIs by serving as potential reservoirs for microorganisms. Promising results have been observed with fecal microbiota transplantation (FMT) for treating Clostridium difficile infection, which is often associated with healthcare facilities. FMT prevents disease recurrence by restoring a healthy colonic microbiota and breaking the dysbiotic cycle. Furthermore, microbiota-based interventions have the potential to control emerging multidrug-resistant pathogens such as vancomycin-resistant enterococci and carbapenem-resistant Enterobacteriaceae. [ABSTRACT FROM AUTHOR]