In Korea, vancomycin-resistant enterococci have become important nosocomial pathogens since the late 1990s, and most vancomycin-resistant enterococcal isolates have been VanA phenotype-vanA genotype strains. In 2001, we experienced an outbreak of VanB phenotype-vanA genotype vancomycin-resistant enterococci at a university hospital. This is the first report of VanB-vanA vancomycin-resistant ent...

We highlight the detection of a rare vanM genotype in Enterococcus faecium. This isolate exhibited a VanB phenotype, with high levels of resistance to vancomycin (MIC, >256 mg/liter) and susceptibility to teicoplanin (MIC, 1 mg/liter). It was, however, vanB negative by PCR. Further screening for other van loci revealed the presence of a complete vanM operon.

We compared PCR to conventional culture for the detection of vancomycin-resistant enterococci (VRE) in 30,835 rectal samples over a 3-year period. The positive and negative predictive values of vanB PCR were 1.42% and 99.9%, respectively. A positive vanB result by PCR is poorly predictive and necessitates culture for differentiation of VRE-positive and -negative individuals.

Six VanB phenotype-vanA genotype isolates of Enterococcus faecium with heterogeneous expression of teicoplanin resistance which gave rise to an outbreak at a Korean tertiary care teaching hospital have IS1216V in the coding region of vanS. This could be the underlying cause of the VanB phenotype-vanA genotype with heterogeneous expression of teicoplanin resistance.

Glycopeptide-resistant enterococci (GRE) associated with multiple antibiotic resistance present a major challenge to clinical practice and infection control due to limited or nonexistent antimicrobial treatment options. The genes encoding VanA- and VanB-type glycopeptide resistance have been shown to reside on transposons Tn1546 and Tn1547, respectively. These transferable genetic elements may ...

Here we describe the detection and characterisation of three isolates of vancomycin-resistant VanB-type Enterococcus faecalis. Sequence analysis suggested that these isolates harboured the vanB1 gene. The isolates were susceptible to the majority of antimicrobial agents tested, with the exception of chloramphenicol, erythromycin and vancomycin, and showed distinct profiles of high-level resista...

OBJECTIVES AND METHODS The transferability of vanA and vanB glycopeptide resistance determinants with a defined plasmid (n = 9) or chromosomal (n = 4) location between Enterococcus faecium strains of human and animal origins was compared using filter mating (in vitro) and germ-free mice (in vivo) as experimental models. Moreover, the stability of exconjugants in vivo in the absence of antibioti...