Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “enterococci”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources
PubMed1994

Bactericidal action of gentamicin against enterococci that are sensitive, or exhibit low- or high-level resistance to gentamicin.

Treatment of serious enterococcal infection involves the use of penicillin-aminoglycoside combination therapy if the aminoglycoside minimum inhibitory concentration (MIC) is < or = 2000 micrograms/ml, and the organism is susceptible to penicillin or ampicillin. We evaluated killing of 15 enterococci that differ in their susceptibility to gentamicin using time-kill studies at different gentamicin concentrations. Sensitive strains had a uniform population killed by gentamicin concentrations equal to or above the MIC. Low-level resistant strains (MIC > or = 8 but < or = 2000 micrograms/ml of gentamicin) had a diverse population with large numbers of cells killed at one-half the MIC, while the highly resistant strains (MIC > 2000 micrograms/ml) showed no killing by any concentration of gentamicin.

Drug Resistance, Microbial↗
PubMed1994

Characterization of enterococci isolated from human and nonhuman sources in Brazil.

A total of 330 enterococci strains isolated from several human (272 strains) and animal (27) clinical specimens and environmental sources (31) in Brazil were identified to species level. Major human sources included urine (48.5%), blood (15.8%), and wounds (9.5%). Human isolates were identified as Enterococcus faecalis (90.0%), E. faecium (6.9%), E. gallinarum (1.1%), E. durans (0.8%), E. casseliflavus (0.4%), E. raffinosus (0.4%), and E. mundtii (0.4%). Strains isolated from animals were composed of E. hirae (40.7%), E. faecalis (33.3%), E. faecium (18.5%), and E. casseliflavus (7.5%). Among environmental isolates, 42.0% were E. faecalis, 35.4% E. faecium, 13.0% E. hirae, 6.4% E. casseliflavus, and 3.2% E. durans. Antimicrobial susceptibility tests were performed for 200 strains. Overall, high-level resistance (HLR) to aminoglycosides was found in 66 (33.0%) of the strains tested. HLR to gentamicin was detected in 11.5% of the strains, whereas 19.0% of the strains showed HLR to streptomycin and 26.0% showed HLR to kanamycin. Five (22.7%) of the E. faecium strains were resistant to ampicillin [minimum inhibitory concentration (MIC) > 32 micrograms/ml]. Vancomycin MIC50 and MIC90 were 2 and 4 micrograms/ml, respectively; only eight strains (identified as E. casseliflavus or E. gallinarum) had MIC of 8 micrograms/ml. No beta-lactamase activity was detected by the nitrocefin test.

Animals↗
PubMed1995

In vitro activity of RP 59500 (quinupristin/dalfopristin) against antibiotic-resistant strains of Streptococcus pneumoniae and enterococci.

The activity of RP 59500 (quinupristin/dalfopristin) was evaluated in vitro against antibiotic-resistant strains of Streptococcus pneumoniae (N = 15) and Enterococcus spp. (N = 43). By broth dilution MIC tests RP 59500 was highly active against penicillin-resistant S. pneumoniae and vancomycin-resistant Enterococcus faecium, but showed poor activity against E. faecalis. In time-kill studies the drug was rapidly bactericidal against S. pneumoniae but failed to kill most enterococci, even in the presence of gentamicin or human serum.

Drug Resistance, Microbial↗
PubMed1995

Selective media for detecting gastrointestinal carriage of vancomycin-resistant enterococci.

Nosocomial infection with vancomycin-resistant enterococci (VRE) has become a significant problem. Effective institution of infection control measures depends on rapid identification of carriage of the organism, especially in asymptomatic individuals. We compared two selective media for use in screening for the presence of VRE and found that an agar medium containing bile esculin azide supplemented with 8 mu g/ml of vancomycin was a useful and cost-effective means for primary screening for asymptomatic gastrointestinal carriage of VRE.

Anti-Bacterial Agents↗
PubMed1996

Glycopeptide resistance in enterococci.

Glycopeptide resistance in enterococci results from the production of peptidoglycan precursors with low affinity for these antibiotics. The mobility of the resistance genes by transposition and conjugation and the ability of the resistance proteins to interfere with synthesis of normal precursors in different hosts indicate that dissemination into other bacterial species should be anticipated.

Anti-Bacterial Agents↗
PubMed2004

Prediction rules to identify patients with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci upon hospital admission.

BACKGROUND: In 2003, the Society of Healthcare Epidemiology of America (SHEA) recommended surveillance cultures upon hospital admission for patients at high risk for carriage of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to assess the validity of factors from past medical history in defining patients at high risk for subsequent positive cultures with VRE or MRSA upon hospital admission. METHODS: Subjects were adult inpatients admitted to nonintensive care wards of the index hospital during 2001-2002. Cases had MRSA or VRE positive clinical cultures within 48 hours of hospital admission. Patients with previous history of MRSA or VRE were excluded. RESULTS: Nineteen thousand three hundred ninety-nine patients were included, with 273 cases of VRE or MRSA. Previous admission within 1 year of current admission had a sensitivity of 56.8% and a specificity of 88.4% for predicting a case of MRSA or VRE. Individually, the sensitivity and specificity for admission within the past year were 50.5% and 88.4%, respectively, for MRSA and 76.9% and 88.4%, respectively, for VRE. CONCLUSIONS: Patients with a previous hospital admission represent a high-risk population for positive culture for VRE and MRSA and may be a group of which active surveillance is indicated.

Adult↗
PubMed2004

Impact of a formulary switch from ticarcillin-clavulanate to piperacillin-tazobactam on colonization with vancomycin-resistant enterococci.

BACKGROUND: The prevalence of vancomycin-resistant enterococci (VRE) is increasing, despite infection control measures. Limited data link ticarcillin-clavulanate to higher VRE prevalence. METHODS: Active surveillance for VRE was conducted before and after a formulary switch from ticarcillin-clavulanate to piperacillin-tazobactam. Rectal swabs were obtained serially in 863 adult patients admitted to intensive care units (ICUs) between November 1, 2000 and September 30, 2004. RESULTS: In the postswitch period, 38 of 497 (7.6%) patients acquired VRE versus 42 of 366 (11.5%) patients in the preswitch period. Survival analysis showed an overall hazard ratio (HR) of .68 postswitch versus preswitch ( P = .07), with the greatest change in the surgical ICU (HR = .17, P = .006). Multivariate analysis showed an overall HR = .51 ( P = .004). Hospital-wide, nonstool VRE clinical cultures fell from 39 (.58/1000 patient days) in the 10-month preswitch period to 27 (.33/1000 patient days) in the 12-month postswitch period. Infection control practices and use of other antibiotics remained stable. CONCLUSIONS: VRE acquisition appeared to decrease in association with a formulary change from ticarcillin-clavulanate to piperacillin-tazobactam.

Anti-Bacterial Agents↗
PubMed2005

Enterococci spp. isolated from Cuba: species frequency of occurrence and antimicrobial susceptibility profile.

This study investigated the species distribution and antimicrobial resistance among 99 enterococci isolated from hospitalized patients in 12 hospitals in Cuba from October 2000 to September 2001. Species identification was performed by WIDER Automatic System (Francisco Soria Melguizo, Madrid, Spain), and the susceptibility testing was performed by disk diffusion, agar dilution, and E-test methods. Enterococcus faecalis was the most prevalent (85%) species, followed by E. faecium (10%), E. gallinarum (2%), E. casseliflavus (2%), and E. durans-hirae (1%). A higher percentage of resistance to ampicillin (50%), fosfomycin (40%), ciprofloxacin (30%), norfloxacin (20%), and tetracycline (90%) was detected in E. faecium isolates, whereas E. faecalis strains showed higher rates of resistance to erythromycin (52.4%), chloramphenicol (34.5%), rifampicin (62.5%), moxifloxacin (3%), and nitrofurantoin (2.4%). Resistance to glycopeptide was detected in E. faecalis (1.2%) and E. faecium (10%). Thirty-one E. faecalis (37%) and 3 E. faecium (30%) showed a high-level resistance to gentamicin. The results of this work will be very helpful to guide empirical antimicrobial therapy and the implementation of infection control measures in Cuban hospitals.

Drug Resistance, Bacterial↗
PubMed2005

Identification of glycopeptide-resistant enterococci by VITEK 2 system and conventional and real-time polymerase chain reaction.

Glycopeptide-resistant enterococci (GRE) are important causes of nosocomial infections in the United States and in Europe. Rapid detection of GRE is essential for the implementation of appropriate control measures to prevent the spread of GRE. In this study, we compared the reliability of 3 different methods, VITEK 2 automated system (bioMérieux), a conventional multiplex polymerase chain reaction (m-PCR) protocol, and a real-time PCR protocol performed on the LightCycler system (Roche) for identification of GRE in the routine microbiology laboratory. Species identification and glycopeptide resistance determination was tested with 80 enterococcal isolates with different glycopeptide resistance phenotypes. With the VITEK 2 system, 39% of the strains were correctly identified to species level. Resistance to vancomycin was detected in all isolates; however, discrepancies occurred in the correct detection of teicoplanin resistance. The PCR protocols proved to be suitable for detecting clinically relevant GRE; 90% of the isolates studied were correctly identified with the conventional m-PCR and 100% of vanA and vanB isolates with the real-time PCR protocol, respectively. High specificity and rapidity make the real-time PCR assays superior tools for identification of GRE in clinical samples; however, they do not have the ability to detect vanC.

Anti-Bacterial Agents↗
PubMed2006

Clinical evaluation of repetitive sequence-based polymerase chain reaction using the Diversi-Lab System for strain typing of vancomycin-resistant enterococci.

The reliability of the Diversi-Lab System, an automated method of microbial strain typing using repetitive sequence-based polymerase chain reaction (rep-PCR), was evaluated by comparing results with those obtained by pulsed-field gel electrophoresis (PFGE). Ninety-five clinical isolates of vancomycin-resistant enterococci (VRE; 13 groups, 2-17 isolates per group) sent to Associated Regional and University Pathologists (ARUP) Laboratories for typing were tested by both methods. Rep-PCR and PFGE results were concordant for 83 isolates: all 32 isolates in 6 of the groups and 51 of the 63 isolates in the other 7 groups. Clustering of the remaining 12 isolates differed. With the Diversi-Lab System, analysis is objective, and results are available in 4 h, compared with a more subjective analysis and a 2- to 3-day turnaround time for PFGE. The Diversi-Lab System may be a viable alternative to PFGE for typing VRE in clinical reference laboratories.

Bacterial Typing Techniques↗
PubMed2006

The clinical impact of linezolid susceptibility reporting in patients with vancomycin-resistant enterococci.

Linezolid remains a mainstay of therapy for vancomycin-resistant enterococci (VREs), but resistance has emerged. We describe a cohort of 20 patients with linezolid-intermediate or resistant VRE (LIRVRE) reported by Etest and disk diffusion testing, 18 of whom demonstrated linezolid susceptibility by agar dilution on further investigation. Patients with reported LIRVRE were matched based on culture site and enterococcal species to patients with linezolid-susceptible VRE (LSVRE) in a 1:3 ratio. Patients with reported LIRVRE developed more nosocomial infections (P = .04), had more central lines placed (P = .04), and underwent more computed tomography scans related to VRE infection (P = .02). Multivariate analysis revealed increased surgical procedures related to VRE infections (P = .008), increased linezolid use during hospital stay (P = .03), and delayed culture and susceptibility results compared with those with LSVRE (P = .006). Therefore, inaccurate detection and reporting of LIRVRE by disk diffusion and Etest is associated with increased patient morbidity and resource use.

Academic Medical Centers↗
PubMed2005

Chemiluminescence of enterococci isolates from freshwater.

All Enterococcus spp., isolated from environmental water samples (n=81), emitted a high chemiluminescence signal in the presence of luminol (10(-2) M). Kinetic studies of chemiluminescence show a close correlation between chemiluminescence and growth curves during the exponential phase, with a maximum chemiluminescence reached just before bacterial growth entered in the stationary phase. On the other hand, genera closely related to Enterococcus such as Streptococcus or Lactococcus produced a very weak chemiluminescent signal. Chemiluminescence of enterococci could therefore offer a rapid test, in aiding the identification of the genus Enterococcus and in the survey of the microbiological quality of water supplies.

Bacterial Typing Techniques↗
PubMed2004

Linezolid and quinupristin/dalfopristin resistance in vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus prior to clinical use in Turkey.

The aim of this study was to determine the in vitro antimicrobial activity of recently licensed quinupristin/dalfopristin and linezolid which have not yet been in clinical use in Turkey against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) strains isolated from various clinical specimens by using the Etest. The results showed that all MRSA strains were fully susceptible to both the new compounds. All strains were inhibited by 1 mg/l quinupristin/dalfopristin (mode MIC 0.38 mg/l) and by 3 mg/l linezolid (mode MIC 1.5 mg/l). Four strains of Enterococcus faecium showed an increase of resistance of 2-3 mg/l to quinupristin/dalfopristin (susceptible mode MIC 0.38 mg/l). With linezolid, all strains except two fell within the range 0.75-2.0 mg/l.

Acetamides↗
PubMed2004

Rapid detection and differentiation method of VanA, VanB and VanC phenotypes in vancomycin-resistant enterococci.

We developed a simple method that can replace the polymerase chain reaction (PCR) to distinguish between vancomycin-resistant enterococci (VRE) with the vanA, vanB and vanC genes. The method is based on induction of teicoplanin resistance by vancomycin in vanB-VRE, while the two compounds have a synergistic effect in vanC-VRE. In addition, vanA-VRE shows resistance to both vancomycin and teicoplanin, and both the compounds can induce resistance to vanA-VRE. Utilising these properties, we attempted to develop a simple method to distinguish between vanA, vanB and vanC. We compared our simple method with the PCR method in 43 strains of vanA-VRE, 35 strains of vanB-VRE and 37 strains of vanC-VRE. The results were 100% consistent with that obtained by PCR.

Anti-Bacterial Agents↗
PubMed2004

In vitro antibacterial activity of echinomycin and a novel analogue, YK2000, against vancomycin-resistant enterococci.

The in vitro inhibitory and bactericidal activity of echinomycin and its the novel synthetic analogues of echinomycin,YK2000 and YK2005, were evaluated using 93 clinical isolates of vancomycin-resistant enterococci (VRE). In agar dilution tests, the MIC(90) of echinomycin and YK2000 were 0.125 and 8 mg/l, respectively, using Mueller-Hinton II agar, while that of YK2005 was 32 mg/l. Bactericidal activity of echinomycin and YK2000 were two to four times higher than the MIC in time-kill assay experiments. These results suggest that echinomycin and its analogues might be useful as anti-VRE drugs.

Anti-Bacterial Agents↗
PubMed2005

Antimicrobial resistance of enterococci in Turkey.

Susceptibility to ampicillin, penicillin, vancomycin and teicoplanin, high-level resistance to aminoglycosides (gentamicin and streptomycin) and beta-lactamase production were investigated among 264 consecutive clinical enterococcal isolates in Turkey. Disc diffusion test was used to detect resistance to ampicillin, penicillin, vancomycin and teicoplanin. High-level resistance to aminoglycosides was determined both by standard agar screening and by disc diffusion methods. The values of minimum inhibitory concentration (MIC) of each isolate for ampicillin, vancomycin and teicoplanin were determined by the microbroth dilution technique. The isolates were found to consist of Enterococcus faecalis (78%), Enterococcus faecium (9%) and Enterococcus spp. (12%). In all strains, the penicillin and ampicillin resistance ratios were 27% and 26%, respectively. Enterococcus faecalis was more susceptible to penicillin and ampicillin than the other strains. None of the strains were resistant to glycopeptides. High-level aminoglycoside resistance was found in 16% E. faecalis and 88% E. faecium for gentamicin, and 35% and 44%, respectively, for streptomycin. There were no differences between the two methods used to determine the aminoglycoside resistance rates in the enterococcal isolates. No beta-lactamase-producing isolates were detected in either species. In conclusion, to determine the resistance of enterococci to the penicillin group of drugs by the disc diffusion method, both penicillin and ampicillin discs should be evaluated. In serious enterococcal infections, before starting combined therapy, high-level aminoglycoside resistance should be investigated.

Aminoglycosides↗
PubMed2005

Nosocomial infections due to methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci at a university hospital in Taiwan from 1991 to 2003: resistance trends, antibiotic usage and in vitro activities of newer antimicrobial agents.

A rapid increase of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection (from 39% in 1991 to 75% in 2003) and vancomycin-resistant enterococci (VRE) (from 1.2% in 1996 to 6.1% in 2003) at a university hospital in Taiwan was found. The noticeable rise of MRSA and VRE was significantly correlated with the increased consumption of glycopeptides, beta-lactam-beta-lactamase inhibitor combinations, extended-spectrum cephalosporins, carbapenems and fluoroquinolones (Pearson's correlation coefficient, P < 0.05). Minimum inhibitory concentrations (MICs) of 100 non-duplicate blood isolates of MRSA (in 2003) and of 25 non-duplicate isolates of vancomycin-resistant Enterococcus faecalis and 172 vancomycin-resistant Enterococcus faecium (in 1996-2003) causing nosocomial infection recovered from various clinical specimens of patients treated at the hospital to nine antimicrobial agents were determined by the agar dilution method. All of these isolates were susceptible to linezolid and were inhibited by 0.5mg/L of tigecycline, and all MRSA isolates were inhibited by daptomycin 1mg/L, including two isolates of MRSA with heteroresistance to vancomycin. Daptomycin had two-fold better activity against vancomycin-resistant E. faecalis (MIC90, 2 mg/L) than against vancomycin-resistant E. faecium (MIC90, 4 mg/L). Decreased susceptibilities of vancomycin-resistant E. faecium and MRSA to quinupristin/dalfopristin (non-susceptibility 25% and 8%, respectively) were found. Telithromycin had poor activity against the isolates tested (MIC90, 8 mg/L). Linezolid, daptomycin and tigecycline may represent therapeutic options for infections caused by these resistant Gram-positive organisms.

Anti-Bacterial Agents↗