Application of DNA probes for rRNA and vanA genes to investigation of a nosocomial cluster of vancomycin-resistant enterococci.
DNA probes specific for genes encoding rRNA and the glycopeptide resistance gene vanA were used to investigate a cluster of vancomycin-resistant (MICs, > 512 mg/liter) Enterococcus faecalis and Enterococcus faecium isolated from separate patients in a renal unit in a London hospital. When digested with BamHI, 12 of 13 vancomycin-resistant E. faecalis isolates exhibited a common restriction fragment length polymorphism pattern of rRNA genes (ribotype). A vanA probe hybridized with chromosomal DNA in these 12 isolates. The other isolate of vancomycin-resistant E. faecalis had a different ribotype and the vanA gene was located on plasmid DNA. These data suggest that cross-infection with a single strain of vancomycin-resistant E. faecalis occurred in most instances. In contrast, 23 vancomycin-resistant E. faecium isolates showed greater heterogeneity, comprising 8 ribotypes, suggesting that multiple strains were present in the unit. Twenty-one of these 23 isolates harbored a 24-MDa plasmid which hybridized with the vanA probe, implying that interstrain dissemination of a vancomycin resistance plasmid may have occurred among E. faecium isolates in the renal unit.
Woodford
N
N
Laboratory of Hospital Infection, Central Public Health Laboratory, London, England.
Morrison
D
D
Johnson
A P
AP
Briant
V
V
George
R C
RC
Cookson
B
B
D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D019729:Carbon-Oxygen Ligases; D015342:DNA Probes; D004352:Drug Resistance, Microbial; D016983:Enterococcus / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D013293:Enterococcus faecalis / Q000145:classification / Q000187:drug effects / Q000235:genetics; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects / Q000235:genetics; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology; D006436:Hemodialysis Units, Hospital; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012150:Polymorphism, Restriction Fragment Length; D012335:RNA, Ribosomal / Q000235:genetics / Q000302:isolation & purification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000302:isolation & purification; D012338:RNA, Ribosomal, 23S / Q000235:genetics / Q000302:isolation & purification; D014640:Vancomycin / Q000494:pharmacology*
D001426:Bacterial Proteins; D015342:DNA Probes; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; C071437:VanA ligase, Bacteria; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases