The emergence of community-associated methicillin-resistant Staphylococcus aureus at a London teaching hospital, 2000-2006.
We used ciprofloxacin susceptibility as a phenotypic marker of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in a London hospital collection of MRSA isolates from inpatients, outpatients and primary-care clinics during 2000-2006. Four-hundred and fifty-eight ciprofloxacin-susceptible (Cip-S) MRSA isolates were reported; antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) type, spa type and the presence of Panton-Valentine leukocidin (PVL) genes were determined for all 194 surviving Cip-S MRSA isolates. Multilocus sequence typing and pulsed-field gel electrophoresis were performed on representative isolates. Clinical and epidemiological features of Cip-S MRSA infections were consistent with CA-MRSA, the incidence of which increased markedly during the study period from 49 in 2000 to 102 in 2006. Most (82.0%) of the surviving Cip-S MRSA isolates were SCCmec IV and 25.3% were PVL-positive. Considerable clonal heterogeneity was noted among the recovered isolates, including the t044/ST80-IV European clone and the PVL-negative t127/ST1-IV clone; PVL-positive t008/ST8-IV (USA300) isolates were rare. Ciprofloxacin susceptibility is a useful screening marker of CA-MRSA strains in London, which are more frequent than previously thought and whose incidence is increasing.
Guy's and St Thomas' Hospital, and King's College London, London, UK.
J A
JA
Otter
G L
GL
French
D000328:Adult; D015373:Bacterial Typing Techniques; D002939:Ciprofloxacin / Q000494:pharmacology*; D017714:Community-Acquired Infections / Q000453:epidemiology*; D004269:DNA, Bacterial / Q000302:isolation & purification; D006784:Hospitals, Teaching; D006801:Humans; D015994:Incidence; D008131:London / Q000453:epidemiology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000472:pathogenicity*
D004269:DNA, Bacterial; D002939:Ciprofloxacin