Intra-hospital dissemination of quinupristin/dalfopristin- and vancomycin-resistant Enterococcus faecium in a paediatric ward of a German hospital.
OBJECTIVE
To demonstrate nosocomial transmission of Enterococcus faecium resistant to quinupristin/dalfopristin and vancomycin/teicoplanin among paediatric patients in a German hospital ward.


METHODS
Multiply-resistant E. faecium were isolated from three female patients aged 9 months, 2 and 15 years during a 10 day time span. Antibiotic susceptibilities were determined by microbroth dilution. Clonal relatedness among the isolates was investigated via SmaI-macrorestriction analysis by PFGE, multilocus sequence typing (MLST), and plasmid profiling. Presence of virulence and resistance determinants was tested by polymerase chain reaction (PCR). Selected resistance genes were localized by Southern hybridizations.


RESULTS
A single E. faecium isolate per patient was investigated. All exhibited resistances to quinupristin/dalfopristin, vancomycin/teicoplanin, streptomycin (high-level), penicillin/ampicillin, erythromycin, oxytetracycline, chloramphenicol, rifampicin and fusidic acid. The isolates were susceptible to linezolid only and intermediately resistant to fluoroquinolones including moxifloxacin. PFGE revealed identical patterns for all three isolates. PCRs for virulence determinants hyaluronidase and enterococcal surface protein, esp, were negative, whereas PCR for the enterocin A gene was positive. MLST identified clonal type [8-5-1-1-1-1-1] belonging to a clonal subgroup C1 of hospital- and outbreak-related E. faecium. Southern hybridizations located several resistance genes (erm(B), vat(D), vanA) on a large plasmid, which was transferable in mating experiments with an E. faecium recipient.


CONCLUSIONS
These data show routes of dissemination of resistance to multiple antibiotics including streptogramins and glycopeptides in E. faecium via vertical and/or horizontal gene transfer. The isolates spread in the absence of a direct selective pressure, as none of the patients had received earlier streptogramin or glycopeptide therapy.
Werner
Guido
G
Robert Koch Institute, Wernigerode Branch, Burgstr. 37, 38855 Wernigerode, Germany. wernerg@rki.de
Klare
Ingo
I
Spencker
Friedrich-Bernhard
FB
Witte
Wolfgang
W
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D003428:Cross Infection / Q000382:microbiology* / Q000635:transmission*; D004351:Drug Resistance; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology* / Q000635:transmission*; D006801:Humans; D015278:Intensive Care Units, Pediatric; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020713:Vancomycin Resistance; D014769:Virginiamycin / Q000031:analogs & derivatives* / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D014769:Virginiamycin; C113825:quinupristin