We investigated the antibiotic susceptibility of glycopeptide-resistant enterococci (GRE). Seventy consecutive GRE were tested. Sixty-two isolates were identified as Enterococcus faecium (88.6%), and 8 (11.4%) as Enterococcus faecalis. All strains were susceptible to linezolid and daptomycin, while 17.1% (12/70) and 11.4% (8/70) were resistant to quinupristin/dalfopristin (QD) and tigecycline, respectively. All E. faecalis isolates were resistant to QD, while 4 of 62 (6.5%) E. faecium isolates were resistant to QD. All E. faecalis isolates were susceptible to tigecycline, while 14.5% (9/62) E. faecium isolates were resistant. Continued surveillance of GRE antibiotic susceptibilities is important for combating these multi-resistant nosocomial pathogens.
Daptomycin* ; Enterococcus faecalis ; Enterococcus faecium ; Linezolid ; Teicoplanin

BACKGROUND: Three chromogenic media using direct inoculation were compared with enriched enterococcosel broth for vancomycin-resistant Enterococcus faecium and/or Enterococcus faecalis (VRE) surveillance. METHODS: A total of 174 rectal swabs were included for VRE surveillance. The specimens were transferred in enterococcosel broth (EB). An aliquot of the broth was inoculated onto Brilliance VRE, chromID VRE, and VRESelect media and incubated for up to 48 h. We examined each media and EB after 24 h and 48 h of incubation. When appropriately colored colonies were observed, identification was confirmed using the VITEK-2 system and/or VITEK MS. Vancomycin susceptibility was confirmed by disk diffusion test. The presence of resistance genes was confirmed using Anyplex VanR Real-time Detection (Seegene, Korea). RESULTS: Of the 174 rectal swab specimens, 73 VRE were isolated. For enterococcosel broth, Brilliance VRE, chromID VRE, and VRESelect, the sensitivity at 24 h was 79.2%, 83.3%, 79.2%, and 79.2%, respectively. The sensitivity at 48 h was 91.7%, 93.1%, 91.4%, and 90.3%, respectively. The specificity at 24 h was 85.3%, 97.1%, 98.0%, and 98.0%, while that at 48 h was 79.4%, 85.3%, 95.2%, and 95.1%, respectively. The specificity of chromogenic media at 24 h and 48 h was significantly higher than that of EB. Furthermore, the specificity at 48 h was significantly higher for chromID VRE and VRESelect than Brilliance VRE, although color distinction was easier with VRESelect. CONCLUSION: Based on our results, use of chromID VRE or VRESelect is more reliable and convenient for screening of VRE. In addition, five vanA-positive Enterococcus gallinarum, Enterococcus avium and Enterococcus durans were isolated, and two of them (one E. avium and one E. durans) were detected only on VRESelect.
Diffusion ; Enterococcus ; Enterococcus faecalis ; Enterococcus faecium ; Mass Screening ; Sensitivity and Specificity ; Vancomycin

Adult ; Endocarditis, Bacterial ; microbiology ; Enterococcus faecium ; Humans ; Male

BACKGROUND: Vancomycin-resistant enterococci (VRE) have been increasingly reported worldwide. The understanding of VRE dissemination in the hospital requires a molecular typing of the strains. VRE appeared recently in Chonnam University Hospital. The purpose of this study is to analyse the strains for their genetic relatedness. METHODS: Nine vancomycin-resistant E. faecium isolates, collected from six patients during 1995-1996 in Chonnam University Hospital, were typed using plasmid DNA and RAPD analyses. The plasmid DNA of the isolates was obtained by a alkaline lysis method. For RAPD, eight random primers were used. The cluster analysis was performed by NTSYS-pc (numerical taxonomy system and multivariate analysis system, version 1.50, Applied Biostatistics Inc., CA). RESULTS: Nine VRE isolates were separated into two different molecular types (group A and B) by the plasmid DNA patterns, which were agreed with the RAPD results: the isolates of each group showed the same plasmid DNA patterns and high similarity values in the RAPD analysis. Group A was consisted of two strains isolated from two patients who were admitted at the same room in May 1995. Seven strains of group B were isolated from four patients in the different wards during June 1995 to June 1996. CONCLUSIONS: Nine VRE isolates from six patients were typed to two groups by plasmid DNA or RAPD analysis. These results suggested the intrahospital spread of two clonal strains of vancomycin-resistant E. faecium.
Biostatistics ; Classification ; DNA* ; Enterococcus faecium* ; Enterococcus* ; Humans ; Jeollanam-do ; Molecular Typing ; Multivariate Analysis ; Plasmids*

The isolation of clinical strains of enterococci requiring vancomycin for growth has been reported, but transient strain has not been reported. Transient glycopeptide-dependent Enterococcus f aecium was isolated from the blood of a 59-year-old female with advanced rectal carcinoma during long term broad-spectrum antimicrobial therapy. This strain showed transient glycopeptide dependency, but glycopeptide-resistant revertants were found on subculture to blood agar without vancomycin. It was found to be the vanA genotype by the polymerase chain reaction analysis.
Agar ; Enterococcus faecium* ; Enterococcus* ; Female ; Genotype ; Humans ; Middle Aged ; Polymerase Chain Reaction ; Sepsis* ; Vancomycin

BACKGROUND: Enterococcus faecium (E. faecium) is potential pathogens of mixed infections for which a broad-spectrum antimicrobial agents such as imipenem has a therapeutic role. But controversy continues concerning testing imipenem versus enterococci. The purpose of this study were 1) to investigate the ability of penicillin and ampicillin minimum inhibitory concentration (MIC) to predict in vitro susceptibility of E. faecium versus imipenem. and 2) to compare MICs of ampicillin, penicillin and imipenem by the Vitek system with those by agar dilution method. METHODS: Fifty-two isolates of E. faecium between April 2002 and May 2002 were tested. Each isolate was tested versus penicillin, ampicillin and imipenem. MICs were determined by Vitek system and agar dilution method according to NCCLS guidelines. Imipenem MIC determinations were repeated by E-test. RESULTS: MIC of Vitek system tends to be lower than that of agar dilution method, but there was good concordance between MICs of penicillin and ampicillin by Vitek system and agar dilution method. But for imipenem, the MICs by the agar dilution method did not correspond with the Vitek results. Of the 52 E. faecium isolates tested, in vitro activity of penicillin and ampicillin accurately predicts that of imipenem. CONCLUSIONS: MICs of ampicillin and penicillin are reliable, but imipenem MIC is not reliable for E. faecium by Vitek system. In vitro activity of penicillin and ampicillin versus E. faecium accurately predicts that of imipenem.
Agar ; Ampicillin ; Anti-Infective Agents ; Coinfection ; Enterococcus faecium* ; Enterococcus* ; Imipenem* ; Microbial Sensitivity Tests ; Penicillins

BACKGROUND: Vancomycin-resistant enterococci (VRE) were first recovered from clinical isolates in Korea in 1992, and the incidence has been steadily increasing. Alternatives to vancomycin are few because VRE are frequently resistant to commonly used antimicrobial agents. The present study was designed to assess the in-vitro activity of fosfomycin to clinical isolates of VRE. METHODS: For 199 VRE isolates from 1995 to 2000, and 91 enterococcal isolates that were consecutively isolated during the January of 2001 at Wonju Christian Hospital, fosfomycin (200 microgram) disk diffusion test was done by NCCLS method. The number of enterococcal isolates tested for fosfomycin were as follows:58 E. faecalis (42 vancomycin susceptible isolates, 16 vancomycin resistant isolates, and 1 vancomycin intermediate resistance isolate); 210 E. faecium (185 vancomycin resistant and 25 vancomycin susceptible isolates); 15 E. gallinarum, and 6 E. casseliflavus isolates. RESULTS: Among the VRE isolates, the resistance rates of fosfomycin according to enterococcal species were 6.3% in E. faecalis, 4.9% in E. faecium, 0% in E. casseliflavus, and 16.7% in E. gallinarum. CONCLUSION: Fosfomycin could be a potentially useful drug for the treatment of infections caused by VRE.
Anti-Infective Agents ; Diffusion ; Enterococcus faecalis ; Enterococcus faecium ; Fosfomycin* ; Gangwon-do ; Incidence ; Korea ; Vancomycin*

Vancomycin-resistant enterococci (VRE) infection is a serious problem because optimal therapy has not been established. Different agents in various combinations, including teicoplanin, chloramphenicol, and quinupristin/dalfopristin, have been used to treat patients with VRE meningitis, but the efficacy of these agents is not satisfactory because of their limited ability to penetrate into the cerebrospinal fluid. We report a case of nosocomial vancomycin-resistant Enterococcus faecium meningitis in a patient with ventriculoperitoneal shunt that was successfully treated with linezolid. We will also review previously reported cases of vancomycin-resistant E. faecium meningitis treated by linezolid.
Acetamides ; Chloramphenicol ; Enterococcus ; Enterococcus faecium ; Humans ; Linezolid ; Meningitis ; Oxazolidinones ; Teicoplanin ; Vancomycin ; Ventriculoperitoneal Shunt

BACKGROUND: Vancomycin-resistant Enterococci (VRE) infections are caused by Enterococcus faecium in about 90% of the cases but can also be caused by Enterococcus faecalis. Thus, this study investigates factors that cause a low isolation rate of vancomycin-resistant E. faecalis (VREfs). To this end, the authors study the clinical traits, resistant gene structure, genomic classification, and molecular characteristics of the virulent factor. METHODS: From January 2001 through September 2011, 17 vanA-containing E. faecalis isolates were collected from hospitalized patients at Ajou University Hospital in Korea. Identification, antimicrobial susceptibility testing, and PCR of van and esp genes were performed. Pulsed-field gel electrophoresis (PFGE) was used for strain typing. PCR and sequencing of the internal regions of Tn1546 were performed for structural analysis of the van gene. RESULTS: Of 4,235 VRE infections, 3,918 (92.5%) were caused by E. faecium, and 95 (2.2%) were caused by E. faecalis. In 67% of VREfs infections, there was a preceding occurrence of E. faecium infection. All isolates were of genotype vanA. Our isolates were divided into three types according to the distribution of IS elements integrated into Tn1546 (types I to IIb). The PFGE results showed no clonal relatedness among isolates. CONCLUSION: Our study found that VREfs infections affect patients who have experienced vancomycin-resistant E. faecium. (VREfm) infection or undergo invasive procedures. The VREfs seems to involve the horizontal transfer of Tn1546 transposon from VREfm.
Classification ; DNA Transposable Elements ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecalis* ; Enterococcus faecium ; Enterococcus* ; Epidemiology* ; Genotype ; Humans ; Korea ; Polymerase Chain Reaction

BACKGROUND: Multilocus sequence typing (MLST) is useful in determining the long-term evolutionary process and minimizes differences in experimental results across individuals and laboratories. It is also useful in determining evolutionary origins and backgrounds of bacterial species. This study carries out MLST analysis on VanA-type vancomycin-resistant Enterococcus faecium isolated from patient specimens in a single university hospital over nine years in order to observe changes in genetic evolution over time. METHODS: During the years from 2007 to 2015, 44 clinical isolates of vanA-containing E. faecium were collected from Ajou University Hospital in Korea. Species were identified by the VitekII system (bio-Merieux, USA), and antibiotic susceptibility testing was performed by disk diffusion and E-test according to Clinical and Laboratory Standards Institute (CLSI) guidelines. To determine genetic relatedness, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF M/S) was employed. To characterize clonal diversity, MLST analysis was used. RESULTS: All isolates were highly resistant to ampicillin, ciprofloxacin, and vancomycin but showed variable levels of resistance to teicoplanin. The 44 clinical isolates were genetically unrelated according to MALDI-TOF M/S analysis. MLST showed that the clinical isolates harbored 6 sequence types (ST), with ST17 (n=19) being the most common, followed by ST78 (n=13), ST192 (n=6), ST64 (n=4), ST262 (n=1), and ST414 (n=1). CONCLUSION: The MLST analysis showed that the sequence types of most isolates belonged to clonal complex 17 This is consistent with outbreaks in hospitals. We had single observations for ST262 and ST414, suggesting that they were random occurrences. MLST can be useful for speculating the genetic evolution of VanA-containing E. faecium isolates.
Ampicillin ; Ciprofloxacin ; Diffusion ; Disease Outbreaks ; Enterococcus faecium* ; Enterococcus* ; Evolution, Molecular ; Humans ; Korea ; Mass Spectrometry ; Multilocus Sequence Typing* ; Teicoplanin ; Vancomycin