Resistant Enterococci Research Articles

Comprehensive Study of Antibiotic Resistance in Enterococcus spp.: Comparison of Influents and Effluents of Wastewater Treatment Plants

Background/Objectives: The spread of antibiotic resistance, particularly through Enterococcus spp., in wastewater treatment plants (WWTPs) poses significant public health risks. Given that research on antibiotic-resistant enterococci and their antibiotic-resistance genes in aquatic environments is limited, we evaluated the role of Enterococcus spp. in WWTPs by comparing the antibiotic resistance rates, gene prevalence, biofilm formation, and residual antibiotics in the influent and effluent using culture-based methods. Methods: In 2022, influent and effluent samples were collected from 11 WWTPs in South Korea. Overall, 804 Enterococcus strains were isolated, and their resistance to 16 antibiotics was assessed using the microdilution method. Results: High resistance to tetracycline, ciprofloxacin, kanamycin, and erythromycin was observed. However, no significant differences in the overall resistance rates and biofilm formation were observed between the influent and effluent. Rates of resistance to ampicillin, ciprofloxacin, and gentamicin, as well as the prevalence of the tetM and qnrS genes, increased in the effluent, whereas resistance rates to chloramphenicol, florfenicol, erythromycin, and tylosin tartrate, along with the prevalence of the optrA gene, decreased. E. faecium, E. hirae, and E. faecalis were the dominant species, with E. faecalis exhibiting the highest resistance. Conclusions: Our results suggest that WWTPs do not effectively reduce the rates of resistant Enterococcus spp., indicating the need for continuous monitoring and improvement of the treatment process to mitigate the environmental release of antibiotic-resistant bacteria.

Analysis of a persistent outbreak with vancomycin resistant Enterococcus faecium (VREfm) revealed the need for an adapted diagnostic algorithm

Our setting was challenged with an outbreak of different vancomycin resistant Enterococcus faecium (VREfm) including vanA and/or vanB containing isolates. Remarkably, it was observed that screening by use of a vanA and vanB real-time PCR on overnight enriched specimens from time to time tested positive for VanB with very low Ct-values, whereas VREfm-specific enrichment cultures remained negative. Here, we describe the analysis of the diagnostic results leading to adaptation of the diagnostic algorithm. Per specimen of each patient, results of the vanA and vanB screening PCR and of the VREfm-specific culture (Brilliance VRE) were collected and combined with genotyping data of the identified VREfm isolates. During the outbreak, a second VREfm-specific culture medium (CHROMagar VRE) was introduced, and results were compared to the results obtained with Brilliance VRE agar. Thirty-five patients were identified as VREfm-carrier, in which four different strains were identified comprising vanA (STnew-CT7088) and/or vanB (ST80-CT1065, ST117-CT7117 and ST117-CT7118). Complementing results of PCR, culture and genotyping revealed that culture with Brilliance VRE agar was inadequate for detection of the vanB ST117 isolates identified, irrespective of vancomycin MIC values. In contrast, CHROMagar VRE was able to correctly detect these vanB ST117 isolates and other tested isolates. Our data showed that the vanB ST117 containing isolates were inadequately detected by the VREfm-specific culture media, possibly contributing to unnoticed spread of VREfm. For this reason, CHROMagar VRE was evaluated during the outbreak and subsequently implemented in routine diagnostics, replacing Brilliance VRE agar.

Prevention of possible vancomycin resistant enterococcus outbreak caused by infants transferred due to earthquake-trauma

Infection control measures are disrupted due to the large number of patients admitted in a very short time, in the early post-earthquake period. Inter-hospital or intra-hospital transfers can cause the spread of resistant bacteria. We reported the possible outbreak and its prevention caused by vancomycin-resistant enterococcus (VRE) strains carried by infants transferred from another unit to our neonatal intensive care unit after the earthquake. Screening cultures (rectal swab) were obtained from infants on admission and patients were kept in contact isolation. We studied the clonal analysis of VRE strains isolated from patients by Pulse Field Gel Electroforesis.

Seafood as a source of antibiotic resistant Enterococcus spp

Seafood is a crucial global food source, but its role as a reservoir for antibiotic-resistant pathogens is concerning. This study focuses on the prevalence of antibiotic resistance in retail seafood, using Enterococcus spp. as an indicator. Seven categories of raw seafood were collected from retail markets in Central Italy. Out of 422 samples, 288 tested positive for Enterococcus spp., resulting in a prevalence rate of 68.25% (CI95%: 63.66%-72.51%). The most common species were E. faecalis (48%) and E. faecium (17.4%). Enterococcus spp. was most frequently found in cephalopods, salmon, bivalves, and crustaceans than in sea bass and bream. The odds of Enterococcus spp. recovery were higher in frozen than in fresh samples, while there was no difference between farm-raised and wild-caught seafood. A subset of 102 isolates was selected for antibiotic resistance testing, showing the highest resistance rates to quinupristin/dalfopristin (52.94%) and tetracycline (27.45%). Over 70% of isolates were multidrug-resistant. Additionally, strains resistant to vancomycin and oxazolidinones, two last-resort antimicrobials, were detected. Vancomycin resistance was observed in E. casseliflavus and E. gallinarum, which are naturally resistant due to the vanC chromosomal cluster. The optrA gene, responsible for resistance to oxazolidinones and phenicols, was found in E. thailandicus and E. faecium, where it was located on to a transferable plasmid. In conclusion, this study confirms the widespread presence of Enterococcus spp. in retail seafood. The detection of multi-resistant isolates and resistance to last-resort antimicrobials highlights significant human health risks, stressing the importance of including Enterococcus spp. in seafood antibiotic resistance surveillance.

Phenotypic and molecular characterization of vancomycin resistant Enterococci from wild birds: First detection of a plasmid-borne vanC1 in Enterococcus faecalis.

Vancomycin-resistant enterococci (VRE) are a public health concern as they lead to therapeutic impasses and play a pivotal role in the dissemination of vancomycin resistance genes. As recent evidence suggests that wildlife can play a role in the dissemination of bacterial resistomes, this study explored the potential role of Algerian wild birds as a reservoir of VRE. A total of 222 cloacal and fecal samples were collected from various wild bird species and screened for VRE using a selective medium. Of the 47 isolated strains, 22 were identified as Enterococcus casseliflavus with the vanC2/C3 gene, 24 as Enterococcus gallinarum (19 carrying vanC1 and five carrying vanC2/C3), and one strain as Enterococcus faecalis with the vanC1 gene. Twenty-four (24) strains were multidrug-resistant with 61.7% resistant to rifampicin while no resistance to teicoplanin, linezolid and gentamicin was found. Additionally, 53.20% of the strains exhibited at least one virulence factor. To our knowledge, this study represents the first documentation of the vanC1 gene in E. faecalis isolated from wild birds. Furthermore, this gene was found to be carried by a conjugative plasmid, highlighting its ability to spread among bacterial populations and lead to the emergence of novel resistance phenotypes.

Green synthesis of cerium oxide nanoparticles usingTribulus terrestris: characterization and evaluation of antioxidant, anti-inflammatory and antibacterial efficacy against wound isolates.

Multi-drug resistance (MDR) infections are a significant global challenge, necessitating innovative and eco-friendly approaches for developing effective antimicrobial agents. This study focuses on the synthesis, characterization, and evaluation of cerium oxide nanoparticles (CeO2NPs) for their antioxidant, anti-inflammatory, and antibacterial properties. The CeO2NPs were synthesized using aTribulus terrestrisaqueous extract through an environmentally friendly process. Characterization techniques included UV-visible spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), x-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive x-ray (EDX) analysis. The UV-vis spectroscopy shows the presence of peak at 320 nm which confirms the formation of CeO2NPs. The FT-IR analysis of the CeO2NPs revealed several distinct functional groups, with peak values at 3287, 2920, 2340, 1640, 1538, 1066, 714, and 574 cm-1. These peaks correspond to specific functional groups, including C-H stretching in alkynes and alkanes, C=C=O, C=C, alkanes, C-O-C, C-Cl, and C-Br, indicating the presence of diverse chemical bonds within the CeO2NPs. XRD revealed that the nanoparticles were highly crystalline with a face-centered cubic structure, and SEM images showed irregularly shaped, agglomerated particles ranging from 100-150 nm. In terms of biological activity, the synthesized CeO2NPs demonstrated significant antioxidant and anti-inflammatory properties. The nanoparticles exhibited 82.54% antioxidant activity at 100 μg ml-1, closely matching the 83.1% activity of ascorbic acid. Additionally, the CeO2NPs showed 65.2% anti-inflammatory activity at the same concentration, compared to 70.1% for a standard drug. Antibacterial testing revealed that the CeO2NPs were particularly effective against multi-drug resistant strains, includingPseudomonas aeruginosa,Enterococcus faecalis, and MRSA, with moderate activity againstKlebsiella pneumoniae. These findings suggest that CeO2NPs synthesized viaT. terrestrishave strong potential as antimicrobial agents in addressing MDR infections.

Mustard Gel versus Chlorhexidine Gel as Root-Canal Medicament Against Enterococcus Faecalis: An in vitro Study.

To evaluate the efficacy of mustard gel versus chlorhexidine (CHX) gel in treating the most resistant Enterococcus faecalis (E. faecalis) bacteria as intra-canal medications. Randomised controlled trial (in vitro study). Place and Duration of the Study: Department of Operative Dentistry, de'Montmorency College of Dentistry, in collaboration with Lahore General Hospital, between March and October 2021. Forty single-rooted teeth, extracted and randomly allocated, were divided into two groups. Group 1 underwent treatment with CHX gel, while Group 2 was treated with Mustard gel. Subsequently, after disinfection, each tooth was horizontally divided into three equal parts. The middle section was standardised and inoculated with a controlled strain of E. faecalis. Intra-canal medicaments were administered for seven days. Bacterial colonies were quantified as colony forming units (CFU/mL) and subjected to analysis using Statistical Package for Social Sciences (SPSS) version 25. The median bacterial count observed was 1,550 (range 775 - 2,500) for Group 1, contrasting with 400 (range 200 - 775) for Group 2, indicating a significant difference in bacterial count between the groups (p <0.001). Mustard gel demonstrated significantly superior efficacy compared to chlorhexidine gel against E. faecalis in root canal procedures. Chlorhexidine, Enterococcus faecalis, Mustard, Root canal medicament, Antimicrobial drug-resistance, Root canal irrigants.

Expression of Pili Genes (ebpA and ebpC) Associated with Multi Drug Resistant Enterococcus faecalis Isolates

The antibiotic susceptibility was determined for 118 clinical E. faecalis isolates , the isolates showed various levels of susceptibilities to different antibiotics and 70.5% of these isolates were multidrug resistant. The relative expression of ebpA gene in six multidrug resistance E. faecalis isolates was determined in comparison with antibiotic-sensitive isolates selected as a control sample. The isolate 21 from root canal (multi drug resistance) showed increasing in expression in comparison with antibiotic sensitive isolates of E. faecalis. The relative expression of ebpC gene in multidrug resistance E. faecalis isolates was determined in comparison with antibiotic sensitive isolates which were selected as control samples. The isolate 21 from root canal and the isolates 19 from urine (multi drug resistance) showed high expression in comparison with antibiotic sensitive isolates of E. faecalis. The expression of ebpA and ebpC genes in multi drug resistance isolates in relation to their sources showed that urine group gave a high rate of expression of ebpC followed by root canal in comparison with ebpA expression. In contrast, the vagina group gave a higher expression of ebpA than ebpC. The findings of the present investigation revealed a significant correlation (P=0.05) between the multi-drug resistance and gene expression of ebpA gene, while there is no significant (P=0.05) correlation with ebpC.

Restoring vancomycin activity against resistant Enterococcus faecalis using a transcription factor decoy as a vanA operon-inhibitor.

Vancomycin-resistant enterococci (VRE) represent a public health threat due to the few available treatments. Such alarm has triggered worldwide initiatives to develop effective antimicrobial compounds and novel delivery and therapeutic strategies. vanA operon is responsible for most cases of acquired vancomycin resistance in enterococci. Development of a transcription factor decoy (TFD) system as a vanA gene transcription-inhibitor. Vancomycin MIC was determined in the presence of TFD-lipoplexes. Additionally, the effect of TFD-lipoplexes on the expression level of the vanA gene and the growth pattern of E. faecalis was evaluated. The haemolytic activity of the developed TFD-lipoplexes and their cytotoxicity were examined. TFD-lipoplexes efficiency in treating vancomycin-resistant E. faecalis (VREF) infection was tested in vivo using a systemic mice infection model. A reduction in vancomycin MIC against VRE from 256 mg/L (resistant) to 16 mg/L (intermediate susceptible), in the presence of TFD-lipoplexes, was recorded. The developed TFD-lipoplexes lacked any effect on E. faecalis growth and significantly reduced the transcription level of the vanA gene by about 3-fold. In an initial evaluation of the safety of TFD-lipoplexes, they were found not to be overtly haemolytic to human blood or cytotoxic to human skin fibroblast cells. The co-administration of TFD-lipoplexes and vancomycin efficiently eradicated VREF infection in vivo. The developed TFD-lipoplexes successfully restored vancomycin activity against VREF. They offer a safe effective unconventional therapy against this stubborn organism and present a revolution in gene therapy that can be applied to other resistance-encoding genes in various organisms.

V-313.3: Vancomycin resistant enterococcus infection in multivisceral transplant and small bowel transplant recipients: A 10-year single center experience.

V-313.3: Vancomycin resistant enterococcus infection in multivisceral transplant and small bowel transplant recipients: A 10-year single center experience.

Australian Group on Antimicrobial Research surveillance outcome programs - bloodstream infections and antimicrobial resistance patterns from patients less than 18 years of age, January 2020 - December 2021.

From 1 January 2020 to 31 December 2021, thirty-eight institutions across Australia submitted data to the Australian Group on Antimicrobial Resistance (AGAR) from patients aged < 18 years (AGAR-Kids). Over the two years, 1,679 isolates were reported from 1,611 patients. This AGAR-Kids report aims to describe the population of children and adolescents with bacteraemia reported to AGAR and the proportion of resistant isolates. Overall, there were 902 gram-negative isolates reported: 800 Enterobacterales, 61 Pseudomonas aeruginosa and 41 Acinetobacter spp. Among the Enterobacterales, 12.9% were resistant to third generation cephalosporins; 11.6% to gentamicin/tobramycin; and 11.2% to piperacillin-tazobactam. In total, 14.5% of Enterobacterales were multi-drug resistant (MDR). Only 3.3% of P. aeruginosa were resistant to carbapenems and 4.9% were MDR. Resistance in Acinetobacter spp was uncommon. Of 607 Staphylococcus aureus isolates, 12.9% were methicillin-resistant (MRSA). Almost half of S. aureus isolates from the Northern Territory were MRSA. In S. aureus, resistance to erythromycin was 13.2%; 12.4% to clindamycin; and 5.3% to ciprofloxacin. Resistance to all antibiotics tested was higher in MRSA. Overall, 6.5% of S. aureus were MDR, of which 65% were MRSA. Almost three-quarters of the 170 Enterococcus spp. reported were E. faecalis, and half were from patients < 1 year old. Ampicillin resistance in enterococci was 19.6%. Eight isolates were vancomycin resistant and three isolates were teicoplanin resistant. Five E. faecium isolates were classified as MDR. This AGAR-Kids report highlights clear differences in the geographic distribution of pathogens and resistance profiles across Australia.

Identification of vancomycin resistance in enterococcus &amp; determination of minimal inhibitory concentration of vancomycin by E-test

Infections due to Enterococcal species is 2 prevalent cause of Nosocomial Infections in health care settings. They are crucial because to their inherent resistance to penicillins, cephalosporins, and low level aminoglycosides &amp; their tendency to develop higher level of aminoglycoside and vancomycin resistance, which leaves few therapeutic alternatives for therapy. Isolation and identification of Enterococci with their Antibiogram &amp; determination of Minimal Inhibitory Concentration (MIC) of Vancomycin by E-test. The antibiogram generated by Kirby Baur disc diffusion method and standard microbiological procedures were used to identify enterococcal isolates from distinct clinical samples. MIC level for Vancomycin was tested for all the isolates using E-test from BIOMERIEUX. Total of 108 isolates (62 E.faecalis and 46 E. faecium) were tested by E-test for MIC of Vancomycin, of which 40 (37.03%) (22 E.faecalis &amp; 18 E. faecium) were Vancomycin Resistant (VRE) strains, having MIC level &amp;#62;32 μg/ml. Nine strains out of 40 (45%) were found to have MIC &amp;#62;256 μg/ml. The enterococcal isolates were observed to be sensitive to Linezolid (80%), Ofloxacin (74%), Amoxyclav (74%) and Cefaperazone (70%). For the Indian medical community, the rise of antibiotic resistance among Enterococcal species has been a significant concern. So this is need of present era that our laboratories must be well-equipped to report the resistance patterns displayed by enterococci in order to practise evidence-based medicine and reduce hospital acquired infections.

Identification of key drivers of antimicrobial resistance in Enterococcus using machine learning.

With antimicrobial resistance (AMR) rapidly evolving in pathogens, quick and accurate identification of genetic determinants of phenotypic resistance is essential for improving surveillance, stewardship, and clinical mitigation. Machine learning (ML) models show promise for AMR prediction in diagnostics but require a deep understanding of internal processes to use effectively. Our study utilised AMR gene, pangenomic, and predicted plasmid features from 647 Enterococcus faecium and Enterococcus faecalis genomes across the One Health continuum, along with corresponding resistance phenotypes, to develop interpretive ML classifiers. Vancomycin resistance could be predicted with 99% accuracy with AMR gene features, 98% with pangenome features, and 96% with plasmid clusters. Top pangenome features overlapped with the resistance genes of the vanA operon, which are often laterally transmitted via plasmids. Doxycycline resistance prediction achieved approximately 92% accuracy with pangenome features, with the top feature being elements of Tn916 conjugative transposon, a tet(M) carrier. Erythromycin resistance prediction models achieved about 90% accuracy, but top features were negatively correlated with resistance due to the confounding effect of population structure. This work demonstrates the importance of reviewing ML models' features to discern biological relevance even when achieving high-performance metrics. Our workflow offers the potential to propose hypotheses for experimental testing, enhancing the understanding of AMR mechanisms, which are crucial for combating the AMR crisis.

Measuring the efficacy of standard and novel disinfection methods on frequently used physical therapy equipment: a 2-phase prospective randomized controlled trial.

Frequently used physical therapy (PT) equipment is difficult to disinfect due to equipment material and shape. The efficacy of standard disinfection of PT equipment is poorly understood. We completed a 2-phase prospective microbiological analysis of fomites used in PT at our hospital from September 2022 to October 2023. For both phases, study fomites were obtained after usage and split into symmetrical halves for sampling. In phase 1, sides were sampled following standard disinfection. In phase 2, sides were randomized 1:1 to intervention or control. Samples were obtained before and after the intervention, a disinfection cabinet using Ultraviolet C (UV-C) and 6% nebulized hydrogen peroxide. We defined antimicrobial-resistant clinically important pathogens (AMR CIP) as methicillin-resistant staphylococcus aureus (MRSA), Vancomycin Resistant Enterococcus (VRE), and Multidrug resistant (MDR)-Gram-negatives and non-AMR CIP as methicillin-sensitive staphylococcus aureus (MSSA), Vancomycin sensitive Enterococcus (VSE), and Gram-negatives. Three assessments were made: 1) contamination following standard disinfection (phase 1), 2) contamination postintervention compared to no disinfection (phase 2) and, 3) contamination following standard disinfection compared to postintervention (phase 1 vs phase 2 intervention). The median total colony-forming units (CFU) from 122 study fomite samples was 1,348 (IQR 398-2,365). At the sample level, 52(43%) and 15(12%) of samples harbored any clinically important pathogens (CIPs) or AMR CIPs, respectively. The median CFU was 0 (IQR 0-55) in the intervention group and 977 (409-2,547) in the control group (P < .00001). Following standard disinfection, PT equipment remained heavily contaminated including AMR and non-AMR CIPs. Following the intervention, PT equipment was less contaminated and harbored no AMR CIPs compared to control sides supporting the efficacy of the intervention on difficult-to-disinfect PT fomites.

Antimicrobial Resistance of Enterococcus Isolates from Poultry Farms in the Republic of Serbia (Autonomous Province of Vojvodina).

Enterococcus species are significant intestinal commensals of animals, including poultry. However, they have emerged as important opportunistic infective agents in both veterinary and human medicine as well as major nosocomial pathogens, owing to their increasing antimicrobial resistance. This research aimed to investigate the prevalence and antimicrobial resistance patterns of Enterococcus spp. isolated from poultry farms in the north of Serbia. A total of 40 samples of overshoes or feces were collected from 40 poultry farms and analyzed for the presence of Enterococcus spp. using PCR or MALDI-TOF mass spectrometry for their identification. The number of isolates was 40 and included 11 isolates from laying hens, 2 isolates from turkeys, 3 from broiler breeders, and 24 from broilers. The Kirby-Bauer disk diffusion method was used to test for antibiotic susceptibility in accordance with the Clinical and Laboratory Standards Institute and EUCAST guidelines. The results showed that Enterococcus faecalis was isolated from 37.5% farms, and E. faecium from 42.5%. E. hirae was identified in 15% of poultry establishments, and E. durans and E. thialandicus on 2.5%. Notably, resistance to erythromycin, streptomycin, fluoroquinolones, and tetracyclines among the frequently used antibiotics was found. Furthermore, 35% of the isolates had multidrug resistance (MDR). In order to prevent the spread of antibiotic resistance in chicken farming and protect the health of the public and animals alike, our findings highlight the critical need for improved surveillance and control measures. To effectively establish a containment strategy for Enterococcus spp. isolated from poultry farms, more research into the processes behind their antibiotic resistance is required.

Q48K mutation in the type IB nitroreductase NrmA is responsible for nitrofurantoin resistance in Enterococcus faecium

ObjectivesNitrofurantoin is recommended as first-line therapy for the optimal treatment of uncomplicated urinary tract infections (UTIs) caused by enterococci and Escherichia coli. However, the mechanisms of nitrofurantoin resistance in enterococci have not been elucidated. This study aimed to investigate the mechanisms of nitrofurantoin resistance in E. faecium, focusing on the role of the nitroreductase NrmA. MethodsEnterococcus strains isolated from the urinary tract samples were collected and were tested for nitrofurantoin susceptibility. Potential genes associated with nitrofurantoin resistance were screened in the NCBI nucleotide database and by polymerase chain reaction (PCR). Complementation assays and enzyme kinetic tests were performed to assess the impact of the Q48K mutation in NrmA on nitrofurantoin resistance. ResultsOf the 128 E. faecium isolates tested, 59 (46.1%) were resistant to nitrofurantoin. Analysis revealed the presence of a type IB nitroreductase, designated NrmA, in all E. faecium strains studied, shared 18.7% sequence identity with nitroreductase NfsB in E. coli. Different from NrmA in nitrofurantoin-susceptible E. faecium, nitrofurantoin-resistant strains had a single amino acid substitution, i.e., a lysine instead of a glutamine at position 48 (Q48K mutation). Complementation assays of nitrofurantoin-resistant E. faecium HS17-112 showed that the nitrofurantoin minimal inhibitory concentration of the complemented strain HS17-112: pIB166-nrmA (wild type [WT]) decreased from 128 mg/L to 4 mg/L. Compared with NrmA (WT), NrmA (Q48K) showed significantly reduced catalytic efficiency, with a kcat/Km value decreasing from 0.122 µM−1 s−1 to 0.000042 µM−1 s−1. ConclusionThe Q48K mutation in nitroreductase NrmA is responsible for nitrofurantoin resistance in E. faecium.

Occurrence of Enterococci in the Process of Artisanal Cheesemaking and Their Antimicrobial Resistance.

Enterococci are a group of microorganisms that have a controversial position from some scientific points of view. The species of the greatest clinical importance are E. faecalis and E. faecium, which are common agents of nosocomial infections. However, enterococci also have important applications in the dairy industry, as they are used as non-starter lactic acid bacteria (NSLAB) in a variety of cheeses, especially artisanal cheeses. The aim of this study was to determine the presence of representatives from the Enterococcus genus using PCR and MALDI-TOF MS methods on samples of raw milk, processing environment swabs, and cheese from four different artisanal dairy plants in Slovakia. Among the 136 isolates of enterococci, 9 species of genus Enterococci (E. faecalis, E. faecium, E. durans, E. devriesi, E. hirae, E. italicus, E. casseliflavus, E. malodoratus, and E. gallinarum) were identified and were tested for their antimicrobial resistance (AMR) to 8 antibiotics (amoxicillin, penicillin, ampicillin, erythromycin, levofloxacin, vancomycin, rifampicin, and tetracycline); most of them were resistant to rifampicin (35.3%), ampicillin (22.8%), and tetracycline (19.9%). A PCR analysis of vanA (4.41%) and tetM (14.71%) revealed that antimicrobial resistance genes were present in not only phenotypic resistant isolates of enterococci but also susceptible isolates. The investigation of antimicrobial resistance in enterococci during the cheesemaking process can be a source of valuable information for public health in the concept of "One Health".

Impact of terminal cleaning in rooms previously occupied by patients with healthcare-associated infections.

Healthcare associated infections (HAIs) are costly but preventable. A limited understanding of the effects of environmental cleaning on the riskiest HAI associated pathogens is a current challenge in HAI prevention. This project aimed to quantify the effects of terminal hospital cleaning practices on HAI pathogens via environmental sampling in three hospitals located throughout the United States. Surfaces were swabbed from 36 occupied patient rooms with a laboratory-confirmed, hospital- or community-acquired infection of at least one of the four pathogens of interest (i.e., Acinetobacter baumannii (A. baumannii), methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis/faecium (VRE), and Clostridioides difficile (C. difficile)). Six nonporous, high touch surfaces (i.e., chair handrail, bed handrail, nurse call button, desk surface, bathroom counter near the sink, and a grab bar near the toilet) were sampled in each room for Adenosine Triphosphate (ATP) and the four pathogens of interest before and after terminal cleaning. The four pathogens of interest were detected on surfaces before and after terminal cleaning, but their levels were generally reduced. Overall, C. difficile was confirmed on the desk (n = 2), while MRSA (n = 24) and VRE (n = 25) were confirmed on all surface types before terminal cleaning. After cleaning, only MRSA (n = 6) on bed handrail, chair handrail, and nurse call button and VRE (n = 5) on bathroom sink, bed handrail, nurse call button, toilet grab bar, and C. difficile (n = 1) were confirmed. At 2 of the 3 hospitals, pathogens were generally reduced by >99% during terminal cleaning. One hospital showed that VRE increased after terminal cleaning, MRSA was reduced by 73% on the nurse call button, and VRE was reduced by only 50% on the bathroom sink. ATP detections did not correlate with any pathogen concentration. This study highlights the importance of terminal cleaning and indicates room for improvement in cleaning practices to reduce surface contamination throughout hospital rooms.

Genome analysis of multidrug resistant Enterococcus faecium and Enterococcus faecalis circulating among hospitalized patients in uMgungundlovu District, KwaZulu-Natal, South Africa

BackgroundVancomycin-resistant enterococci (VRE) are important pathogens categorized as high-priority bacteria in the Global Priority List of Antibiotic-Resistant Bacteria to Guide Research, Discovery, and Development of New Antibiotics published by the World Health Organization. The aim of this study was to determine the risk factors, resistance, virulence, mobilomes associated with multidrug-resistant and clonal lineages of Enterococcus faecium and faecalis circulating among hospitalized patients following the health system in South Africa, using whole genome sequencing (WGS).MethodsA cross-sectional study was conducted during a two-month periods among hospitalized patients in 2017. Rectal swabs were collected from patients admitted to medical and surgical wards in an urban tertiary hospital, and a rural district hospital in uMgungundlovu district, South Africa. Enterococci were screened for vancomycin resistance on bile esculin azide agar supplemented with 6 mg/L of vancomycin and confirmation of VRE was done using ROSCO kits. Conventional and real-time PCR methods were used to ascertain the presence of VanA, VanB, VanC-2/3 and VanC-1 genes. All six multidrug-resistant Enterococcus faecalis and faecium selected were identified using multiplexed paired-end libraries (2 × 300 bp) with the Nextera XT DNA sample preparation kit (Illumina, San Diego, CA, USA) and genome sequencing was done using Illumina MiSeq instrument with 100× coverage at the National Institute of Communicable Diseases Sequencing Core Facility, South Africa. Antibiotic resistance genes, virulence factors, plasmids, integrons and CRISPR were characterized using RAST, ResFinder, VirulenceFinder, PlasmidFinder, PHAST and ISFinder respectively.ResultsSequencing analysis revealed that these strains harbouring numerous resistance genes to glycopeptides (vanC[100%], vex3[100%], vex2[83,33%] and vanG[16,66%]), macrolides, lincosamides, sterptogramine B (ermB[33,32%], Isa[16,66%], emeA[16,66%]) and tetracyclines (tetM[33,32%]) in both district and tertiary hospitals. Multidrug efflux pumps including MATE, MFS and pmrA conferring resistance to several classes of antibiotics were also identified. The main transposable elements observed were in the Tn3 family, specifically Tn1546. Four single sequence types (STs) were identified among E. faecium in the district hospital, namely ST822, ST636, ST97 along with a novel ST assigned ST1386, while one lineage, ST29 was detected in the tertiary hospital.ConclusionThe study reveals the genetic diversity and high pathogenicity of multidrug-resistant Enterococcus faecalis and faecium circulating among hospitalized patients. It underlines the necessity to implement routine screening of admitted patients coupled with infection control procedures, antimicrobial stewardship and awareness should be strengthened to prevent and/or contain the carriage and spread of multidrug resistant E. faecium and E. faecalis in hospitals and communities in South Africa.

A bacteriocin-based coating strategy to prevent vancomycin-resistant Enterococcus faecium biofilm formation on materials of interest for indwelling medical devices

The ever-increasing use of exogenous materials as indwelling medical devices in modern medicine offers to pathogens new ways to gain access to human body and begin, in some cases, life threatening infections. Biofouling of such materials with bacteria or fungi is a major concern during surgeries, since this is often associated with biofilm formation and difficult to treat, recalcitrant infections. Intense research efforts have therefore developed several strategies to shield the medical devices' surface from colonization by pathogenic microorganisms. Here, we used dopamine as a coupling agent to coat four different materials of medical interest (plastic polyetheretherketone (PEEK), stainless steel, titanium and silicone catheter) with the bacteriocins, enterocin EJ97-short and the thiopeptide micrococcin P1. Water contact angle measurements and x-ray photoelectron spectroscopy were used to verify the effective coating of the materials. The effect of bacteriocins coated on these materials on the biofilm formation by a vancomycin resistant Enterococcus faecium (VRE) strain was studied by biofilm-oriented antimicrobial test (BOAT) and electron scanning microscopy. The in vitro biocompatibility of bacteriocin-modified biomaterials was tested on cultured human cells. The results demonstrated that the binding of the bacteriocins to the implant surfaces is achieved, and the two bacteriocins in combination could inhibit biofilm formation by E. faecium on all four materials. The modified implant showed no cytotoxicity to the human cells tested. Therefore, surface modification with the two bacteriocins may offer a novel and effective way to prevent biofilm formation on a wide range of implant materials.