High-level Gentamicin-resistant Enterococcus Research Articles

Prevalence and Resistance Profiles of Pediatric Enterococcal Isolates: A Five-Year Update from Children's Medical Center Hospital, Tehran.

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. 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). 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%. 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.

Prevalence and antimicrobial susceptibility of high-level gentamicin resistant enterococci isolated from urine at a hospital in Pune, India

Introduction: Enterococci are one of the common organisms isolated from hospitalized patients with urinary tract infections. Guidelines recommend testing enterococcifor susceptibility to high-level gentamicin (HLG) and streptomycin. The present study was planned to determine the susceptibility of uropathogenic enterococci to high-level gentamicin in a tertiary care hospital. Materials and Methods: Prospective observational research was carried out at a tertiary care hospital for two years on all isolated enterococci from urine specimens. Identification and antibiotic susceptibility were performed as per standard methods. All the isolated enterococci were tested for high level gentamicin ((120µg) resistance and susceptibility to other recommended antimicrobial agents by standard methods. Results: A total of 320 uropathogenic enterococci were isolated and tested for antibiotic susceptibility. The majority of enterococci were isolated from elderly (34.06%) and admitted patients (69.06%). A total of 68.4% isolated enterococci were HLG resistant. HLG resistant enterococci were highly resistant to erythromycin (96.3%), ciprofloxacin (96.8%) and nalidixic acid (97.7%). Enterococci sensitive to HLG were significantly (p <0.05) less resistant to the other antimicrobial agents except nalidixic acid. Only 20.5% isolated Enterococci were resistant to vancomycin. All isolated enterococci were susceptible to linezolid. Conclusion: The study demonstrated high prevalence of HLG resistant enterococci causing UTI in our hospital setting. Compared to HLG sensitive enterococci, HLG resistant enterococci were more resistant to other antimicrobial agents tested. The findings highlight the need for mandatory testing of enterococci for HLG resistance to determine effective antimicrobials for treatment. IMC J Med Sci. 2023; 17(2):008. DOI: https://doi.org/10.55010/imcjms.17.018 *Correspondence: Dr. Sahjid Mukhida, Department of Microbiology, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, Maharashtra, India. E-mail: drssmukhida@rediffmail.com

Genomic Features of High-Level Gentamicin-Resistant Enterococcus faecalis Strain LREF-1 from India.

ABSTRACTEnterococcus faecalis strain LREF-1 was isolated from a urine sample from India; it belongs to sequence type 28 (ST28), which is associated with nosocomial infections. The strain carries genes for resistance to multiple antibiotics and resistance to various drug classes, including tetracycline, erythromycin, and high-level gentamicin, along with virulence factors.

Molecular characterization of antimicrobial-resistant Enterococcus faecalis and Enterococcus faecium isolated from layer parent stock

Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) are ubiquitous intestinal bacteria in humans and animals that can easily acquire antimicrobial resistance, which allows them to have roles as antimicrobial resistance indicators. In addition, layer parent stock produces thousands of eggs for the production of commercial laying hens and can transfer a variety of viral and bacterial agents to chicks. The objective of this study was to determine the prevalence and characteristics of antimicrobial-resistant E. faecalis and E. faecium isolated in the layer parent stock level of the egg-layer operating system in South Korea. A total of 129 E. faecalis and 166 E. faecium isolates from 74 flocks of 30 layer parent stock were tested for resistance in this study. The prevalence of doxycycline- (51.9%), erythromycin- (53.5%), high-level gentamicin- (13.2%), high-level kanamycin- (31.0%), high-level streptomycin- (30.2%), and tetracycline- (64.3%) resistant E. faecalis isolates were higher than those for E. faecium isolates (P < 0.05). The ermB gene was detected in 66 (95.7%) erythromycin-resistant E. faecalis isolates, which was higher than that of 32 (71.7%) erythromycin-resistant E. faecium isolates. Twenty-one high-level gentamicin-resistant Enterococcus spp. (17 E. faecalis and 4 E. faecium) carried at least one aminoglycoside-modifying enzyme gene, aac(6')Ie-aph(2')-Ia or ant(6)-Ia. Fourteen isolates that harbored both aac(6')Ie-aph(2')-Ia and ant(6)-Ia exhibited pattern A with IS256 at both ends. Ten high-level ciprofloxacin-resistant Enterococcus spp. (8 E. faecalis and 2 E. faecium) showed amino acid changes from serine to isoleucine at codons 83 in gyrA, and 80 in parC. Also, the virulence genes ace, asa1, efaA, and gelE were detected in this study. To the best of our knowledge, this is the first study to examine the prevalence and characteristics of antimicrobial-resistant E. faecalis and E. faecium isolates in the layer parent stock. Our findings support the need for a surveillance program to monitor the emergence of antimicrobial-resistant E. faecalis and E. faecium in layer operating system.

Prevalence of Genes Encoding Aminoglycoside-Modifying Enzymes in Clinical Isolates of Gram-Positive Cocci in Iran: A Systematic Review and Meta-Analysis.

Introduction: Several studies have investigated the genes encoding aminoglycoside-modifying enzymes (AMEs) among gram-positive cocci (GPC) such as Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), coagulase-negative staphylococci (CoNS), and Enterococcus spp. in Iran; however, a comprehensive analysis has not yet been performed. Thus, the present systematic review and meta-analysis was conducted to determine the prevalence of genes encoding AMEs among GPC in Iran. Methods: A systematic review of the data published in the English and Persian languages from January 2000 to October 2018 was performed by searching different electronic databases (Medline, Embase, Web of Science, and the Iranian Database). Meta-analysis was performed by using the Comprehensive Meta-Analysis (Biostat V2.2) software. Cochran's Q and I2 statistics were used to test heterogeneity, and publication bias was assessed by using funnel plot and Begg's and Egger's tests. Results: Out of 117 studies, 28 were considered eligible for inclusion in the current meta-analysis. The most prevalent AMEs gene among GPC was aac(6')-Ie-aph(2'')-Ia, with a prevalence of 97.7% (95% CI; 94.4-99) in high-level gentamicin-resistant enterococci and 67.7% (95% CI; 59.2-75.2) in MRSA. The second most common gene was ant(4')Ia, with a prevalence of 45.3% (95% CI; 23.9-68.6) in MRSA. Conclusions: It was ultimately determined that the prevalence of AMEs genes among GPC had reached alarming levels in Iran; therefore, aminoglycosides should be prescribed with caution by clinicians. The implementation of a regional and nationwide surveillance system to monitor antimicrobial resistance, especially aminoglycosides, and increasing the awareness of AMEs genes among clinicians are essential to guiding empirical and pathogen-specific therapy.

Increase in antimicrobial resistance and emergence of major international high-risk clonal lineages in dogs and cats with urinary tract infection: 16 year retrospective study.

To evaluate temporal trends in antimicrobial resistance, over 16 years, in bacteria isolated from dogs and cats with urinary tract infection (UTI) and the clonal lineages of bacteria harbouring critical antimicrobial resistance mechanisms. Antimicrobial susceptibility testing was conducted for 948 bacteria isolated from dogs and cats with UTI (1999-2014). Resistance mechanisms were detected by PCR, namely ESBL/AmpC in third-generation cephalosporin (3GC)-resistant Escherichia coli and Proteus mirabilis, mecA in methicillin-resistant staphylococci, and aac(6')-Ieaph(2″)-Ia and aph(2″)-1d in high-level gentamicin-resistant (HLGR) enterococci. Resistant bacteria were typed by MLST, and temporal trends in E. coli and Enterobacteriaceae antimicrobial resistance were determined by logistic regression. Enterobacteriaceae had a significant temporal increase in resistance to amoxicillin/clavulanate, 3GCs, trimethoprim/sulfamethoxazole, fluoroquinolones, gentamicin and tetracycline (P < 0.001). An increase in MDR was also detected (P < 0.0001). 3GC resistance was mainly caused by the presence of blaCTX-M-15 and blaCMY-2 in E. coli and the presence of blaCMY-2 in P. mirabilis. Two major 3GC-resistant E. coli clonal lineages were detected: O25b:H4-B2-ST131 and ST648. The mecA gene was detected in 9.2% (n = 11/119) of Staphylococcus spp., including MRSA clonal complex (CC) 5 (n = 2) and methicillin-resistant Staphylococcus epidermidis CC5 (n = 4). A temporal increase in MDR methicillin-resistant Staphylococcus pseudintermedius was detected (P = 0.0069). Some ampicillin-resistant and/or HLGR Enterococcus spp. were found to belong to hospital-adapted CCs, namely Enterococcus faecalis ST6-CC6 (n = 1) and Enterococcus faecium CC17 (n = 8). The temporal increase in antimicrobial resistance and in MDR bacteria causing UTI in dogs and cats creates important therapeutic limitations in veterinary medicine. Furthermore, the detection of MDR high-risk clonal lineages raises public health concerns since companion animals with UTI may contribute to the spread of such bacteria.

Prevalence of high-level gentamicin-resistant Enterococcus faecalis in an Iranian hospital

This study was designed to determine the molecular characteristic and antimicrobial resistance of e nterococcal strains isolated from patients in an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside [ aac(6 ' )-Ie-aph(2 '' )-Ia , aph (3') , ant (4' )], resistance to vancomycin ( vanA , vanB ), resistance to tetracycline ( tetK , tetL , tetM , tetO ), and resistance to erythromycin ( ermA , ermB , ermC ) by PCR and multiplex PCR–based methods. Genetic diversity was evaluated using Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC ≤ 0.5µg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicin-resistant (HLGR) and multiresistant. The most prevalent aminoglycoside resistance gene was aac(6 ' )-Ie-aph(2 '' )-Ia, found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance gene was tetM , found in 85.1% (23/27) of the isolates followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. Random Amplified Polymorphic DNA (RAPD)-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One clusters of isolates shared the same RAPD patterns, while 16 isolates had unique RAPD patterns. we found that over the examined time period one RAPD genotype were common type and were disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern.

Clinical Usefulness of Arbekacin.

Arbekacin is a broad-spectrum aminoglycoside used to treat methicillin-resistant Staphylococcus aureus (MRSA). Arbekacin has antibacterial activities against high-level gentamicin-resistant Enterococci, multidrug-resistant Pseudomonas aeruginosa, and Acinetobacter baumannii et al. Here, we reviewed in vitro data on arbekacin in Staphylococci and Gram-negative microorganisms. We also reviewed clinical studies for clinical efficacy and microbiologic efficacy data in patients with identified MRSA and suspected MRSA infections. The overall clinical efficacy ranged from 66.7% to 89.7%. The microbiologic efficacy rate ranged from 46.2% to 83%. In comparative studies between arbekacin and glycopeptides, arbekacin was similar to other glycopeptides with respect to clinical and microbiological efficacy rates. Combination trials with other antibiotics suggest that arbekacin will be a promising strategy to control Enterococcus spp. multi-drug resistant P. aeruginosa. The major adverse reaction was nephrotoxicity/hepatotoxicity, but patients recovered from most adverse reactions without any severe complications. Based on these results, arbekacin could be a good alternative to vancomycin/teicoplanin in MRSA treatment. Finally, therapeutic drug monitoring is recommended to maximize clinical efficacy and decrease nephrotoxicity.

Prevalence, antimicrobial resistance and genetic lineages of Enterococcus spp. from vegetable food, soil and irrigation water in farm environments in Tunisia.

The objective of this study was to determine the species, clonal diversity, antibiotic resistance and virulence of enterococci in different environments. Seventy-one samples of farm origin (34 of food vegetables, 27 of soil and ten of irrigation water) and 19 samples of vegetables from five markets, were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 72.2% of tested samples in SB media (food vegetables from farms, 88.2%; soil and irrigation water, 51%; food vegetables from markets, 84.2%), and 65 enterococcal isolates were obtained. Enterococcus faecium was the most prevalent species (52.3%), followed by E. hirae (35.4%), E. faecalis (6.15%), and E. casseliflavus (6.15%). Antibiotic resistance detected among these enterococci was as follows (percentage/detected gene): ciprofloxacin (60%), erythromycin (18.4%/erm(B)), tetracycline (15.4%/tet(M)-tet(L)), kanamycin (15.4%/aph(3')-III), chloramphenicol (7.7%), streptomycin (3%/ant(6)), vancomycin (6.15%/vanC2)), teicoplanin (0%) and ampicillin (0%). High-level gentamicin-resistant (HLR-G) enterococci were detected in SB-Gen plates in 14 of 90 tested samples (15.5%), and 15 isolates were characterized: ten E. faecalis, four E. faecium and one E. hirae. All HLR-G enterococci carried the aac(6')-aph(2″), erm(B) and tet(M) genes, among other resistance genes. The HLR-G isolates showed high genetic diversity (ten different PFGE profiles), and were ascribed to the sequence types ST2, ST16, ST28 and new ST528 (in E. faecalis), and ST56, new ST885 and new ST886 (in E. faecium). Food vegetables in the farm or market settings are frequently contaminated by HLR-G enterococci, and these microorganisms could reach the human intestine through the food chain, if hygienic conditions are not followed. © 2015 Society of Chemical Industry.

Genetic relatedness and risk factor analysis of ampicillin-resistant and high-level gentamicin-resistant enterococci causing bloodstream infections in Tanzanian children.

BackgroundWhile enterococci resistant to multiple antimicrobials are spreading in hospitals worldwide, causing urinary tract, wound and bloodstream infections, there is little published data on these infections from Africa.MethodsWe assessed the prevalence, susceptibility patterns, clinical outcome and genetic relatedness of enterococcal isolates causing bloodstream infections in children in a tertiary hospital in Tanzania, as part of a prospective cohort study of bloodstream infections among 1828 febrile children admitted consecutively from August 2001 to August 2002.ResultsEnterococcal bacteraemia was identified in 2.1% (39/1828) of admissions, and in 15.3% (39/255) of cases of culture-confirmed bloodstream infections. The case-fatality rate in children with Enterococcus faecalis septicaemia (28.6%, 4/14) was not significantly different from those with Enterococcus faecium septicaemia (6.7%, 1/15, p = 0.12). E. faecium isolates commonly had combined ampicillin-resistance and high-level gentamicin resistance (HLGR), (9/17), while E. faecalis frequently displayed HLGR (6/15), but were ampicillin susceptible. None of the tested enterococcal isolates displayed vancomycin resistance by Etest or PCR for vanA and vanB genes. Multi-locus sequence-typing (MLST) showed that the majority of E. faecium (7/12) belonged to the hospital associated Bayesian Analysis of Population Structure (BAPS) group 3–3. Pulsed-field gel electrophoresis (PFGE) indicated close genetic relationship particularly among E. faecium isolates, but also among E. faecalis isolates. There was also correlation between BAPS group and PFGE results. Risk factors for enterococcal bloodstream infection in univariate analysis were hospital-acquired infection and clinical diagnosis of sepsis with unknown focus. In multivariate analysis, neonates in general were relatively protected from enterococcal infection, while both prematurity and clinical sepsis were risk factors. Malnutrition was a risk factor for enterococcal bloodstream infection among HIV negative children.ConclusionThis is the first study to describe bloodstream infections caused by ampicillin-resistant HLGR E. faecium and HLGR E. faecalis in Tanzania. The isolates of E. faecium and E. faecalis, respectively, showed high degrees of relatedness by genotyping using PFGE. The commonly used treatment regimens at the hospital are insufficient for infections caused by these microbes. The study results call for increased access to microbiological diagnostics to guide rational antibiotic use in Tanzania.

High level gentamicin resistance and susceptibility to Vancomycin in enterococci in a tertiary care hospital of Dhaka City

Vancomycin and high level gentamicin resistant enterococci detection is important for effective treatment and control of nosocomial infection. The present study was undertaken to determine the species distribution of Enterococcus and the rate of vancomycin and high level gentamicin resistant enterococci (HLGRE) in clinical samples in a tertiary care hospital of Dhaka city. Enterococci were identified to species level by standard biochemical and serological methods. Their susceptibilities to antibiotics were determined by disc diffusion method according to CLSI guideline. Minimum inhibitory concentration (MIC) of vancomycin and gentamicin were determined by agar dilution method. The study was conducted from July 2009 to February 2010. Among 80 isolates, 95% and 5% were identified as Enterococcus faecalis and Enterococcus faecium respectively. Out of 80 isolates 72 (90%) were sensitive and 8 (10%) were intermediate resistant to vancomycin (30?g) by disc diffusion method, but all isolates were susceptible by agar dilution MIC method. Out of 80 enterococci, 37 (46.25%) showed high level resistance to gentamicin (MIC: &gt; 500 ?g/ml) by MIC method but, initially six of which showed sensitive result to gentamicin by disc diffusion method using 120 ?g disc. The study indicated high prevalence of HLGRE in our hospital population. MIC method was more accurate in detecting high level gentamycin resistant enterococci compared to disc diffusion method with 120 ?g gentamicin disc. However, none of the enterococcal strains showed resistance to vancomycin. HLGRE should be monitored regularly in clinical samples as it is difficult to treat. DOI: http://dx.doi.org/10.3329/imcj.v7i2.20103 Ibrahim Med. Coll. J. 2013; 7(2): 28-31

Performance of Vitek 2 for Antimicrobial Susceptibility Testing of Staphylococcus spp. and Enterococcus spp

Vitek 2 (bioMérieux, Inc., Durham, NC) is a widely used commercial antimicrobial susceptibility testing system. We compared MIC results obtained by Vitek 2 to those obtained by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) reference method for 134 staphylococcal and 84 enterococcal clinical isolates. Nineteen agents were evaluated, including all those available on Vitek 2 for testing staphylococci and enterococci. The resistance phenotypes tested included methicillin-resistant Staphylococcus aureus (MRSA) (n = 58), S. aureus with inducible clindamycin resistance (ICR) (n = 30), trimethoprim-sulfamethoxazole-resistant MRSA (n = 10), vancomycin-resistant Enterococcus (n = 37), high-level gentamicin-resistant Enterococcus (n = 15), linezolid-resistant Enterococcus (n = 5), and daptomycin-nonsusceptible Enterococcus faecalis (n = 6). For the staphylococci, there was 98.9% categorical agreement (CA). There was one very major error (VME) for gentamicin in a Staphylococcus hominis isolate, six VMEs for inducible clindamycin in S. aureus isolates, and two major errors (ME) for daptomycin in an S. aureus and a Staphylococcus epidermidis isolate. For enterococci, there was 97.3% CA. Two VMEs were observed for daptomycin in isolates of E. faecalis and 2 ME, 1 for high-level gentamicin resistance and 1 for nitrofurantoin, in E. faecium isolates. Overall, there was 98.3% CA and 99% essential agreement for the testing of staphylococci and enterococci by the Vitek 2. With the exception of detecting ICR in S. aureus, Vitek 2 performed reliably for antimicrobial susceptibility testing of staphylococci and enterococci.

Molecular characterization of high-level gentamicin-resistant Enterococcus faecalis from chicken meat in Korea

Because the intrinsically antimicrobial-resistant Enterococcus has acquired high-level aminoglycoside resistance genes, treating enterococcal infections is difficult. In this study, of the 101 food-borne Enterococcus faecalis isolates collected from retail chicken meat between 2003 and 2010, 11 high-level gentamicin-resistant (HLGR) E. faecalis isolates (MICs>2,048μg/mL) were found. Molecular characterization was performed to determine the basis of this resistance. All HLGR E. faecalis isolates encoded aac(6′)-Ie–aph(2″)-Ia and harbored at least 3 virulence traits in the asa1, esp, gelE, efaA, ace, and cylA genes. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed to characterize their molecular epidemiology. A total of 8 sequence types (STs), including 3 novel STs, were identified (ST35, ST82, ST116, ST202, ST300, ST403, ST407, and ST420). ST82, which is associated with amyloid arthropathy in poultry, was the most prevalent ST among HLGR E. faecalis isolates (4 out of 11 isolates, 36.4%); all other STs were identified in the isolates as well. The STs of food-borne HLGR E. faecalis in this study have been confirmed as corresponding to clinical isolates in the MLST database (DB), except for ST300 and the new STs. Three out of 11 isolates belonged to CC116, including ST116, ST407, and ST420. This study characterized HLGR E. faecalis isolates and provided evidence for the spread of HLGR E. faecalis with virulence factors to chicken sources in Korea. The emergence of food-borne HLGR E. faecalis suggests that chicken could be a potential source of transmission of antimicrobial resistance and virulence factors.

Prevalence of and Risk Factors for Biliary Carriage of Bacteria Showing Worrisome and Unexpected Resistance Traits

Data on biliary carriage of bacteria and, specifically, of bacteria with worrisome and unexpected resistance traits (URB) are lacking. A prospective study (April 2010 to December 2011) was performed that included all patients admitted for <48 h for elective laparoscopic cholecystectomy in a Spanish hospital. Bile samples were cultured and epidemiological/clinical data recorded. Logistic regression models (stepwise) were performed using bactobilia or bactobilia by URB as dependent variables. Models (P < 0.001) showing the highest R(2) values were considered. A total of 198 patients (40.4% males; age, 55.3 ± 17.3 years) were included. Bactobilia was found in 44 of them (22.2%). The presence of bactobilia was associated (R(2) Cox, 0.30) with previous biliary endoscopic retrograde cholangiopancreatography (ERCP) (odds ratio [OR], 8.95; 95% confidence interval [CI], 2.96 to 27.06; P < 0.001), previous admission (OR, 2.82; 95% CI, 1.10 to 7.24; P = 0.031), and age (OR, 1.09 per year; 95% CI, 1.05 to 1.12; P < 0.001). Ten out of the 44 (22.7%) patients with bactobilia carried URB: 1 Escherichia coli isolate (CTX-M), 1 Klebsiella pneumoniae isolate (OXA-48), 3 high-level gentamicin-resistant enterococci, 1 vancomycin-resistant Enterococcus isolate, 3 Enterobacter cloacae strains, and 1 imipenem-resistant Pseudomonas aeruginosa strain. Bactobilia by URB (versus those by non-URB) was only associated (R(2) Cox, 0.19) with previous ERCP (OR, 11.11; 95% CI, 1.98 to 62.47; P = 0.006). For analyses of patients with bactobilia by URB versus the remaining patients, previous ERCP (OR, 35.284; 95% CI, 5.320 to 234.016; P < 0.001), previous intake of antibiotics (OR, 7.200; 95% CI, 0.962 to 53.906; P = 0.050), and age (OR, 1.113 per year of age; 95% CI, 1.028 to 1.206; P = 0.009) were associated with bactobilia by URB (R(2) Cox, 0.19; P < 0.001). Previous antibiotic exposure (in addition to age and previous ERCP) was a risk driver for bactobilia by URB. This may have implications in prophylactic/therapeutic measures.

Molecular screening of virulence genes in high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium isolated from clinical specimens in Northwest Iran

Purpose: The present study screened clinical isolates of Enterococcus faecalis and Enterococcus faecium to determine the prevalence of high-level gentamicin-resistant enterococci and the potential virulence genes among them. Materials and Methods: Clinical enterococcal isolates were obtained from three university teaching hospitals in Northwest Iran. Isolated enterococci were identified phenotypically followed by antibiotic susceptibility testing. Multiplex PCR was performed for the detection of genus, species-specific targets, gentamicin resistance, and potential virulence genes. Results: Of 220 enterococcal isolates, 133 (60.45%) isolates were identified as high-level gentamicin-resistant. Of these isolates, 79 (59.4%) and 54 (40.6%) were E. faecalis and E. faecium, respectively. All high-level gentamicin-resistant strains carried aac(6′)Ie-aph(2″)Ia. Of 220 isolates, 65.9% were positive for gelE, and 55%, 53.6%, 51.8%, and 49.5% of isolates were positive for cpd, asa1, ace, and esp, respectively. Phenotypically detected β-haemolytic strains (19.54%) were found to possess cylLlsMAB. Conclusion: The study revealed that high-level gentamicin-resistance was related to the presence of aac(6′)Ie-aph(2″)Ia. Isolated enterococci harboured potential virulence determinants, which were more common among E. faecalis than among E. faecium strains.

Porcine-Origin Gentamicin-ResistantEnterococcusfaecalisin Humans, Denmark

During 2001–2002, high-level gentamicin-resistant (HLGR) Enterococcus faecalis isolates were detected in 2 patients in Denmark who had infective endocarditis and in pigs and pork. Our results demonstrate that these isolates belong to the same clonal group, which suggests that pigs are a source of HLGR E. faecalis infection in humans.

Clonal groups of high-level gentamicin-resistantEnterococcus faeciumisolated from municipal wastewater and clinical samples in Tehran, Iran

Clonality among high-level gentamicin-resistant Enterococcus faecium (HLGR-EF) isolates obtained from clinical and sewage treatment plants (STP) were investigated using PhePlate system (PhP), ribotyping and pulsed-field gel electrophoresis (PFGE). During 1 year study (September 2005-2006), a total of 106 HLGR-EF isolates were collected from clinical (n = 48) and STP (n = 58) samples in Tehran, Iran. Biochemical fingerprinting of these isolates using the PhP showed the presence of 21 PhP types (diversity index, Di = 0.97) among the clinical and 21 PhP types (Di = 0.91) among the STP isolates. Representative isolates of each PhP type (n = 42) were further characterized by the ribotyping method. Sixteen ribotypes were identified among the isolates with five types shared between the clinical and STP isolates. PFGE recognized 24 clonal types among these isolates with three pulsotypes shared between the clinical and STP isolates. Combination of the two techniques (PFGE and ribotyping) resulted in 24 (Di = 0.96) and 16 (Di = 0.93) types among the strains isolated from clinical and STP samples, respectively. We concluded that the combination of PhP typing, ribotyping and PFGE could be extremely discriminatory when examining HLGR-EF isolates. The emergence of highly diverse HLGR-EF population in Iran is of serious concern especially because of their multi-resistances.

P28 Clonal diversity of high level gentamicin resistant Enterococcus faecalis isolated from clinical samples in Tehran, Iran

P28 Clonal diversity of high level gentamicin resistant Enterococcus faecalis isolated from clinical samples in Tehran, Iran

Persistent vancomycin and high-level gentamicin-resistant Enterococcus faecium bacteremia and intra-aortic thrombus in an extremely low birth-weight infant

Vancomycin-resistant Enterococcus (VRE) sepsis is emerging as a significant problem in the intensive care setting. The treatment at any age is challenging, but there is a dearth of information on this infection and its treatment in the very premature infant. We describe successful treatment of persistent bacteremia caused by Enterococcus faecium with vancomycin and high-level gentamicin resistance in a 10-day-old former 23-week premature male infant.

Clinical, epidemiological, and microbiological characteristics of bacteremia caused by high-level gentamicin-resistant Enterococcus faecalis

Enterococcus spp bacteremia is associated with high mortality and the appearance of high-level gentamicin resistance (HLGR) created additional challenges for the treatment of these infections. We evaluated the epidemiological and clinical characteristics of patients with bacteremias caused by HLGR and non_HLGR Enterococcus faecalis isolates at a teaching hospital in the State of São Paulo, Brazil. Patients with bacteremia due to E. faecalis diagnosed between January 1999 and December 2003 were included in the study. We collected clinical, epidemiological, and microbiological data from medical records. Banked isolates were typed using pulsed-field gel electrophoresis. We identified 145 cases of E. faecalis bacteremia: 66 (45.5%) were caused by HLGR isolates and 79 (54.5%) by non_HLGR. In the univariate analysis, patients with HLGR infection were older, had higher rates of bladder catheterization, and more often had treatment with cephalosporin, quinolone, and/or carbapenem compared with patients with non_HLGR infection (P < 0.05). Multivariate analysis indicated that older age, hematological malignancy, and previous use of vancomycin were independently associated with HLGR (P < 0.05). Mortality rates were not significantly different among patients with HLGR (50%) and non_HLGR (43%) infections (P = 0.40). Of the 32 genotyped isolates, 16 were distributed into 6 main electrophoresis patterns and 16 others had distinct patterns. E. faecalis bacteremia is associated with high mortality and is frequently caused by HLGR isolates at this teaching hospital. The variability among genotyped isolates suggests that endogenous infections, rather than patient-to-patient transmission of E. faecalis, are more common at this institution.