Macrolide-susceptible probiotic Enterococcus faecium ST296 exhibits faecal-environmental-oral microbial community cycling among beef cattle in feedlots.

Enterococci are included in the United States National Antimicrobial Resistance Monitoring System to track antibiotic resistance among commensal Gram-positive enteric bacteria, largely due to their high abundance in food animals and in retail meat. In the U.S. cattle industry, macrolides are used to prevent and control liver abscesses, which cause significant economic losses. Previous studies have suggested that feeding tylosin and the intensity of the pen environment, both expand and sustain respectively the prevalence of multidrug resistance among enterococci in feedlot cattle. This has led to research into alternative feed supplements and improved stewardship practices. In a randomized controlled trial, we measured the impact of a probiotic and an altered pen environment on antimicrobial resistance among faecal Enterococcus spp. in cattle fed tylosin. Supplementing cattle with an Enterococcus faecium and Saccharomyces cerevisiae-based probiotic yielded the isolation of E. faecium of the probiotic sequence type (ST296) from faecal and environmental samples in treatment groups, as well as from cattle and the manure pack in nearby pens. Of importance, the probiotic strain also was found in a desiccated and milled manure pack sample taken 120 days after the initial trial ended. Phylogenetic and SNP analyses revealed clonal survival and spread compatible with faecal-environmental-oral recycling of the probiotic strain within and among cattle and pens. The increase in prevalence of the ST296 strain occurred concomitant with a decrease in ST240, the dominant sequence type associated with ermB and tet(M) resistance genes in this trial. SIGNIFICANCE AND IMPACT OF THE STUDY: We demonstrate that a macrolide-susceptible probiotic Enterococcus faecium ST296 strain fed to beef cattle becomes fully embedded in the microbial community cycling of bacteria via faecal-environmental-oral transmission within and among feedlot pens. An initial investment in feeding the probiotic is thereby leveraged into expanding numbers of susceptible bacteria in cattle and their environment, even among those cattle fed tylosin.

Probiotic characteristics of bacteriocin-producing Enterococcus faecium strains isolated from human milk and colostrum.

As potential probiotic traits of human milk-isolated bacteria have increasingly been recognized, this study aimed to evaluate the probiotic properties of bacteriocin-producing Enterococcus faecium strains isolated from human milk and colostrum. Among 118 human milk- and colostrum-isolated lactic cocci, only 29 were identified as Enterococcus. Of these, only four Enterococcus faecium isolates exhibited bacteriocigenic activity against several pathogenic Gram-positive bacteria, including Listeria monocytogenes. These isolates exhibited high acid (up to pH 3.0) and bile tolerance (0.5% oxgall) in simulated gastrointestinal conditions, demonstrating their ability to survive through the upper gastrointestinal tract. All of the E. faecium strains were shown to be sensitive to most of the antibiotics including vancomycin, tetracycline, rifampicin, and erythromycin, while they were resistant to kanamycin and chloramphenicol. None of the strains showed any virulence (gelE, agg2, clyA, clyB, clyM) and antibiotic resistance genes (vanA, vanB, ermB, tetM, and aac(6')-le-aph(2″)-la). In addition, all the strains were able to assimilate cholesterol, ranging between 25.2-64.1% and they exhibited variable adherence (19-36%) to Caco-2 cells. Based on the overall results of this in vitro study, four of the E. faecium strains isolated from human milk and colostrum can be considered as promising probiotic candidates; however, further in vivo evaluations are required.

Antimicrobial Activity of Omadacycline Tested against Clinical Bacterial Isolates from Hospitals in Mainland China, Hong Kong, and Taiwan: Results from the SENTRY Antimicrobial Surveillance Program (2013 to 2016).

Omadacycline is a derivative of minocycline and the first agent of the aminomethylcycline class. A total of 3,282 organisms (1 per patient) were consecutively collected from patients hospitalized in China (including Hong Kong) and Taiwan. Susceptibility testing was performed by broth microdilution methods in a central laboratory (JMI Laboratories). The collection included Gram-positive and Gram-negative organisms from patients with pneumonia, bloodstream, skin, community-acquired respiratory, and other infections. Omadacycline was very potent against Staphylococcus aureus (n = 689; MIC50/90, 0.12/0.25 mg/liter), including methicillin-resistant Staphylococcus aureus (MRSA; n = 299; MIC50/90, 0.12/0.5 mg/liter), and had similar activity across geographic regions. Omadacycline was very active against Streptococcus pneumoniae (highest MIC, 0.25 mg/liter), ß-hemolytic streptococci (highest MIC, 1 mg/liter), viridans group streptococci (highest MIC, 0.25 mg/liter), and Enterococcus spp. (highest MIC, 0.5 mg/liter) from all geographic regions. Overall, 53.8% of S. pneumoniae isolates were penicillin resistant (penicillin MIC, ≥2 mg/liter) and 10.7% of enterococci (21.2% among E. faecium isolates) were vancomycin resistant. Omadacycline was active against Haemophilus influenzae (MIC50/90, 0.5/1 mg/liter) regardless of ß-lactamase production and was active against Moraxella catarrhalis (MIC50/90, ≤0.12/0.25 mg/liter). Against Enterobacteriaceae, omadacycline was most active against Escherichia coli (MIC50/90, 1/2 mg/liter), Klebsiella oxytoca (MIC50/90, 1/4 mg/liter), and Enterobacter cloacae (MIC50/90, 2/4 mg/liter). Omadacycline had potent in vitro activity against Gram-positive and Gram-negative pathogens isolated from China and Taiwan and retained activity against problem pathogens, such as MRSA, vancomycin-resistant enterococci (VRE), penicillin-resistant S. pneumoniae (PRSPN), and extended-spectrum ß-lactamase-producing E. coli The observed MIC profile in Chinese isolates was very similar to that seen in the U.S. and European surveillance studies.

Characteristics of clinical and environmental vanM-carrying vancomycin-resistant enterococci isolates from an infected patient.

vanM, an uncommon glycopeptide resistance gene, was first identified in an Enterococcus faecium isolate (Efm-HS0661) from Shanghai, China, in 2006 and has been predominant in this city since 2011. A vanM-carrying E. faecium was isolated from the bloodstream of a patient in an intensive care unit (ICU) in Hangzhou, China, in 2014. Further surveillance screening of a rectal swab and environmental surfaces of the patient yielded a large number of vanM-positive E. faecium. These isolates (including 1 from the bloodstream, 1 from the rectal swab and 43 representative isolates from environmental samples) were classified into four pulsed-field gel electrophoresis (PFGE) patterns and two sequence types (ST78 and ST564). PCR amplification and sequence analysis indicated that the genetic structure surrounding the vanM gene of these isolates was similar to that of the original vanM-carrying isolate Efm-HS0661. This study highlights the emergence of infections and environmental contamination caused by vanM-carrying E. faecium in an ICU of another Chinese city outside of Shanghai.

Post-ERCP infection and its epidemiological and clinical characteristics in a large Chinese tertiary hospital: a 4-year surveillance study.

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed as a treatment for biliary and pancreatic illness in China; however, there are few data available regarding post-ERCP infections. This study aimed to describe the overall incidence of post-ERCP infections and the epidemiological characteristics of infected patients in a large tertiary-care hospital in China. Methods: Real-time surveillance was performed from 2012 through 2015 to identify all healthcare-associated infections (HAIs) that occurred after ERCP, using an automatic system. All HAIs (e.g., cholangtitis, bacteremia) were identified by infection control practitioners and doctors. Inpatient data were automatically collected by the surveillance system. Results: A total of 1743 ERCP operations were included in the study, among these, 132 (7.57%) HAIs were identified. ERCP postoperative infections occurred following different surgical procedures, with infection rates ranging from 3.58 to 13.51%. The most prevalent HAI was biliary tract infection (4.02%), followed by transient bacteremia (1.14%). Overall, 62 cases of bacteremia occurred following ERCP surgery and 34 (54.84%) cases occurred on the day of the operation or 1-day post-surgery. The most prevalent isolates detected during bacteremia were Enterococcus faecium (12/58) and Escherichia coli (11/58). A large proportion (72.73%) of the E. coli isolates and all of the E. faecium isolates were resistant to ciprofloxacin. In addition, only 37.50% of the E. coli isolates were susceptible to ceftriaxone. Conclusions: The high incidence of post-ERCP infection and the prevalence of drug resistance suggests that employing second generation cephalosporin or ceftriaxone as the antibiotic of choice for prophylaxis before ERCP, as recommended by the Chinese clinical application of antibacterial drugs guidelines, may not be effective.

Identification of subclinical transmission of vancomycin-resistant enterococcus within an intensive care unit in Taiwan.

BACKGROUND/PURPOSE: Colonization, infection, and clonal dissemination of vancomycin-resistant enterococcus (VRE) have been reported in the literature. We aimed to investigate the incidence rate of VRE acquisition and route of transmission of VRE within the medical intensive care unit (ICU) to prove whether subclinical transmission occurs in medical ICUs. METHODS: Between March 1, 2012 and September 30, 2013, rectal cultures were obtained from all inpatients on admission and after admission to medical ICU. Strain types of VRE were determined by both multilocus sequence typing and pulsed-field gel electrophoresis. RESULTS: A total of 66 of the 405 rectal swab surveillance cultures obtained from 46 inpatients were positive for VRE, among which 27 inpatients were culture-positive for VRE on admission to medical ICU, and 19 inpatients were initially culture-negative but converted to culture-positive after admission. All isolates carried vanA gene consisting of 51 Enterococcus gallinarum, 13 Enterococcus faecium, and two Eenterococcus casseliflavus. Of the 51 E. gallinarum isolates, 40 were type ST 341, seven were ST 252, two were ST 78, and two were ST 64. The Enterococcus spp., MLST and PFGE subtypes were almost similar among these two groups of inpatients. Linezolid and tigecycline were most active against VRE in vitro. CONCLUSION: Subclinical VRE cross transmission may occur in ICU. Active surveillance and maximal barrier precautions of VRE are required at ICU with high colonization rate of VRE and shall be beneficial.

Optimal dosing regimen of biapenem in Chinese patients with lower respiratory tract infections based on population pharmacokinetic/pharmacodynamic modelling and Monte Carlo simulation.

In this study, a population pharmacokinetic (PPK) model of biapenem in Chinese patients with lower respiratory tract infections (LRTIs) was developed and optimal dosage regimens based on Monte Carlo simulation were proposed. A total of 297 plasma samples from 124 Chinese patients were assayed chromatographically in a prospective, single-centre, open-label study, and pharmacokinetic parameters were analysed using NONMEN. Creatinine clearance (CLCr) was found to be the most significant covariate affecting drug clearance. The final PPK model was: CL (L/h)=9.89+(CLCr-66.56)×0.049; Vc (L)=13; Q (L/h)=8.74; and Vp (L)=4.09. Monte Carlo simulation indicated that for a target of ≥40% T>MIC (duration that the plasma level exceeds the causative pathogen's MIC), the biapenem pharmacokinetic/pharmacodynamic (PK/PD) breakpoint was 4µg/mL for doses of 0.3g every 6h (3-h infusion) and 1.2g (24-h continuous infusion). For a target of ≥80% T>MIC, the PK/PD breakpoint was 4µg/mL for a dose of 1.2g (24-h continuous infusion). The probability of target attainment (PTA) could not achieve ≥90% at the usual biapenem dosage regimen (0.3g every 12h, 0.5-h infusion) when the MIC of the pathogenic bacteria was 4µg/mL, which most likely resulted in unsatisfactory clinical outcomes in Chinese patients with LRTIs. Higher doses and longer infusion time would be appropriate for empirical therapy. When the patient's symptoms indicated a strong suspicion of Pseudomonas aeruginosa or Acinetobacter baumannii infection, it may be more appropriate for combination therapy with other antibacterial agents.

Emergence of daptomycin non-susceptibility in colonizing vancomycin-resistant Enterococcus faecium isolates during daptomycin therapy.

Infections due to vancomycin-resistant enterococci (VRE) are of significant importance in high-risk populations, and daptomycin is a bactericidal antibiotic to treat multidrug-resistant VRE in these patients. The emergence of daptomycin non-susceptibility invasive VRE during daptomycin therapy is a major clinical issue. Here the hypothesis was tested that systemic daptomycin therapy also induces the emergence of daptomycin non-susceptible (DNS-) isolates in colonizing VRE populations. 11 vancomycin-resistant Enterococcus faecium strain pairs recovered from rectal swabs were available for analysis. All initial isolates exhibited daptomycin MICs within the wild type MIC distribution of E. faecium (MIC≤4 mg/L). In follow-up isolates from five patients a 4-16-fold daptomycin MIC increase was detected. All patients carrying DNS-VRE received daptomycin (14-28 days) at 4 mg/kg body weight, while two patients in whom no DNS-VRE emerged were only treated with daptomycin for 1 and 4 days, respectively. Comparative whole genome sequencing identified DNS-VRE-specific single nucleotide polymorphisms (SNP), including mutations in cardiolipin synthase (Cls), and additional SNPs in independent genes potentially relevant for the DNS phenotype. Mutations within cls were also identified in three additional, colonizing DNS-VRE. Of these, at least one strain was transmitted within the hospital. In none of the VRE isolates tested, pre-existing or de novo mutations in the liaFSR operon were detected. This is the first report documenting the emergence of DNS-VRE in colonizing strains during daptomycin treatment, putting the patient at risk for subsequent DNS-VRE infections and priming the spread of DNS-VRE within the hospital environment.

Healthcare-associated vancomycin resistant Enterococcus faecium infections in the Mansoura University Hospitals intensive care units, Egypt.

Vancomycin resistant Enterococcus faecium (VREF) ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs) of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patients who were admitted to the ICUs of the Mansoura University Hospitals (MUHs), and fulfilled the healthcare-associated infection (HAI) criteria. Susceptibility testing was determined using the disk diffusion method. The clonal relationships were evaluated with pulsed field gel electrophoresis (PFGE). Out of 52 E. faecium isolates, 12 (23.1%) were vancomycin resistant. The significant risk factors for the VREF infections were: transfer to the ICU from a ward, renal failure, an extended ICU stay and use of third-generation cephalosporins, gentamicin, or ciprofloxacin. PFGE with the 12 isolates showed 9 different patterns; 3 belonged to the same pulsotype and another 2 carried a second pulsotypes. The similar pulsotypes isolates were isolated from ICUs of one hospital (EICUs); however, all of the isolates from the other ICUs had different patterns. Infection control policy, in conjunction with antibiotic stewardship, is important to combat VREF transmission in these high-risk patients.

Healthcare-associated vancomycin resistant Enterococcus faecium infections in the Mansoura University Hospitals intensive care units, Egypt

Vancomycin resistant Enterococcus faecium (VREF) ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs) of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patients who were admitted to the ICUs of the Mansoura University Hospitals (MUHs), and fulfilled the healthcare-associated infection (HAI) criteria. Susceptibility testing was determined using the disk diffusion method. The clonal relationships were evaluated with pulsed field gel electrophoresis (PFGE). Out of 52 E. faecium isolates, 12 (23.1%) were vancomycin resistant. The significant risk factors for the VREF infections were: transfer to the ICU from a ward, renal failure, an extended ICU stay and use of third-generation cephalosporins, gentamicin, or ciprofloxacin. PFGE with the 12 isolates showed 9 different patterns; 3 belonged to the same pulsotype and another 2 carried a second pulsotypes. The similar pulsotypes isolates were isolated from ICUs of one hospital (EICUs); however, all of the isolates from the other ICUs had different patterns. Infection control policy, in conjunction with antibiotic stewardship, is important to combat VREF transmission in these high-risk patients.

Effects of In-Feed Copper, Chlortetracycline, and Tylosin on the Prevalence of Transferable Copper Resistance Gene, tcrB, Among Fecal Enterococci of Weaned Piglets.

Heavy metals, such as copper, are increasingly supplemented in swine diets as an alternative to antibiotics to promote growth. Enterococci, a common gut commensal, acquire plasmid-borne, transferable copper resistance (tcrB) gene-mediated resistance to copper. The plasmid also carried resistance genes to tetracyclines and macrolides. The potential genetic link between copper and antibiotic resistance suggests that copper supplementation may exert a selection pressure for antimicrobial resistance. Therefore, a longitudinal study was conducted to investigate the effects of in-feed copper, chlortetracycline, and tylosin alone or in combination on the selection and co-selection of antimicrobial-resistant enterococci. The study included 240 weaned piglets assigned randomly to 6 dietary treatment groups: control, copper, chlortetracycline, tylosin, copper and chlortetracycline, and copper and tylosin. Feces were collected before (day 0), during (days 7, 14, 21), and after (days 28 and 35) initiating treatment, and enterococcal isolates were obtained from each fecal sample and tested for genotypic and phenotypic resistance to copper and antibiotics. A total of 2592 enterococcal isolates were tested for tcrB by polymerase chain reaction. The overall prevalence of tcrB-positive enterococci was 14.3% (372/2592). Among the tcrB-positive isolates, 331 were Enterococcus faecium and 41 were E. faecalis. All tcrB-positive isolates contained both erm(B) and tet(M) genes. The median minimum inhibitory concentration of copper for tcrB-negative and tcrB-positive enterococci was 6 and 18 mM, respectively. The majority of isolates (95/100) were resistant to multiple antibiotics. In conclusion, supplementing copper or antibiotics alone did not increase copper-resistant enterococci; however, supplementing antibiotics with copper increased the prevalence of the tcrB gene among fecal enterococci of piglets.

Antimicrobial resistance profile of Enterococcus species isolated from intestinal tracts of hospitalized patients in Jimma, Ethiopia.

BACKGROUND: Multi-drug-resistant Enterococci colonizing the intestinal tract of hospitalized patients are the major source of infection as well as nosocomial spread. Despite worldwide increasing rate of multidrug resistant Enterococci colonization and infection among hospitalized patients, there is scarcity of data from resource limited setting. The present study aimed at determining the antimicrobial resistance profile of Enterococcus species from intestinal tracts of hospitalized patients in Jimma, Ethiopia. METHODS: The study was conducted among hospitalized patients at Jimma University Specialized Hospital, from January to July 2013. Fecal samples were collected and processed for bacterial isolation and susceptibility testing to antimicrobial agents. Stool samples were inoculated onto enterococcus selective media (Bile Esculin azide agar plate) with and without 6 µg/ml of vancomycin. The isolates were identified to genus and species level by cultural characteristics, Gram's stain, catalase test, growth in 6.5% NaCl broth, growth at 45°C, motility test and by using API 20 Streptococcus system. Sensitivity testing was done using Kirby-Bauer disk diffusion method. Minimum inhibitory concentrations for vancomycin were determined using E-test strips. RESULT: Overall, Enterococci were isolated from 114 (76%) of the study subjects. The isolates were Enterococcus faecium (35.1%) followed by Enterococcus faecalis (29.8%), Enterococcus gallinarum (17.5%), Enterococcus casseliflavus (8.8%) and Enterococcus durans (8.8%). Among 114 tested Enterococci isolates, 41 (36%) were resistant to ampicillin, 62 (54.4%) to streptomycin and 39 (34.2%) to gentamycin. Other alternative antibiotics to treat mixed nosocomial infection caused by Enterococci also showed high rate of resistance in vitro: ciprofloxacin (50% of resistance), norfloxacin (49.1%), erythromycin (63.2%), tetracycline (64.9%), chloramphenicol (34.2%), and nitrofrantoin (32.4%). Multiple drug resistance was observed among 89.5% of E. faecium and E. faecalis. Vancomycin resistant Enterococci were observed in 5% of E. faecium isolates. CONCLUSION: This study reveals high rate of fecal colonization by multidrug-resistant Enterococci and prevalence of vancomycin resistance strains. Thus periodic surveillance of antibacterial susceptibilities is recommended to detect emerging resistance and to prevent the spread of antibacterial-resistant strains.

Detection of the classical G2576U mutation in linezolid resistant Staphylococcus aureus along with isolation of linezolid resistant Enterococcus faecium from a patient on short-term linezolid therapy: first report from India.

PURPOSE: Linezolid is an effective drug against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). We describe the emergence of linezolid resistance in MRSA and VRE from India. MATERIAL AND METHODS: One MRSA and two VRE strains were isolated from a patient on linezolid therapy of one week duration. All three isolates were resistant to linezolid with minimal inhibitory concentrations (MIC) ≥4 mg/L. The 746-bp region flanking the possible G2576U mutation on the corresponding DNA from the 23S rRNA was amplified by polymerase chain reaction (PCR) and amplicons were sequenced for all the three isolates. Conjugation experiments using the linezolid resistant MRSA (LRMRSA) and linezolid resistant VRE (LRVRE) isolates as donors and wild strains of corresponding genera as recipients were performed. RESULTS: The MRSA isolate had the classical G2576U mutation. High quality value scores in the sequencing software validated the mutation. Conjugation studies did not indicate presence of transferable resistance for linezolid. Sequencing did not indicate presence of any mutation in the two LRVRE isolates. CONCLUSIONS: This is the first report from India citing resistance in Staphylococcus and Enterococcus against Linezolid.

Vancomycin-variable Enterococcus faecium: in vivo emergence of vancomycin resistance in a vancomycin-susceptible isolate.

We report the emergence of vancomycin resistance in a patient colonized with a vanA-containing, vanRS-negative isolate of Enterococcus faecium which was initially vancomycin susceptible. This is a previously undescribed mechanism of drug resistance with diagnostic and therapeutic implications.

Antibiotic resistance in Enterococcus faecium clinical isolates.

The worldwide ratio of Enterococcus faecalis-Enterococcus faecium infections is currently changing in favor of E. faecium. Intrinsic and acquired antimicrobial resistance traits of this latter species can explain this evolution as well as the diffusion of hospital-adapted strains belonging to the clonal complex CC17. Like other enterococci, E. faecium is naturally resistant to cephalosporins and aminoglycosides (at low level). Because of its high genome plasticity, it can also acquire numerous other resistances. It is noteworthy that most modern isolates of E. faecium are highly resistant to ampicillin while a non-negligible proportion of them (depending on geographical locations) are resistant to glycopeptides (especially in the USA). Even if resistance to newer antimicrobial agents (linezolid, daptomycin, tigecycline) is still uncommon, some clinical isolates with reduced susceptibility or resistance have already been reported and better understanding of resistance mechanisms is needed for prediction and prevention of their dissemination.

Impact of enterococcal colonization and infection in solid organ transplantation recipients from the Swiss transplant cohort study.

BACKGROUND: The burden of enterococcal infections has increased over the last decades with vancomycin-resistant enterococci (VRE) being a major health problem. Solid organ transplantation is considered as a risk factor. However, little is known about the relevance of enterococci in solid organ transplantation recipients in areas with a low VRE prevalence. METHODS: We examined the epidemiology of enterococcal events in patients followed in the Swiss Transplant Cohort Study between May 2008 and September 2011 and analyzed risk factors for infection, aminopenicillin resistance, treatment, and outcome. RESULTS: Of the 1234 patients, 255 (20.7%) suffered from 392 enterococcal events (185 [47.2%] infections, 205 [52.3%] colonizations, and 2 events with missing clinical information). Only 2 isolates were VRE. The highest infection rates were found early after liver transplantation (0.24/person-year) consisting in 58.6% of Enterococcus faecium. The highest colonization rates were documented in lung transplant recipients (0.33/person-year), with 46.5% E. faecium. Age, prophylaxis with a betalactam antibiotic, and liver transplantation were significantly associated with infection. Previous antibiotic treatment, intensive care unit stay, and lung transplantation were associated with aminopenicillin resistance. Only 4/205 (2%) colonization events led to an infection. Adequate treatment did not affect microbiological clearance rates. Overall mortality was 8%; no deaths were attributable to enterococcal events. CONCLUSIONS: Enterococcal colonizations and infections are frequent in transplant recipients. Progression from colonization to infection is rare. Therefore, antibiotic treatment should be used restrictively in colonization. No increased mortality because of enterococcal infection was noted.

Comparison of Enterococcus faecium and Enterococcus faecalis Strains isolated from water and clinical samples: antimicrobial susceptibility and genetic relationships.

Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species.

[Emergence of glycopeptide resistant Enterococcus faecium in Algeria: a case report]. / Émergence d'Enterococcus faecium résistant aux glycopeptides en Algérie : à propos d'un cas.

A glycopeptide-resistant Enterococcus faecium (EFRG) was isolated from a wound in a patient hospitalized in a university hospital in Algiers. This strain was resistant to several antibiotics. This patient was carrying this strain in the digestive tract which may partly explain its origin. Genotypic comparison of the two strains by pulsed field gel electrophoresis showed that it was the same strain. Glycopeptide resistance was due to the presence of the vanA gene. Vigilance is required facing the emergence of strains of EFRG in our hospitals.