a1 Department of Medical Microbiology, Aberdeen Royal Infirmary, Aberdeen, UK
a2 Scottish MRSA Reference Laboratory, Glasgow, UK
a3 Infection Control Team, NHS Grampian, UK
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) with the type IV staphylococcal chromosomal cassette mec (SCCmec) is rarely reported as being acquired in hospital. We report a hospital outbreak, in Grampian, Scotland, of eight cases of skin and soft-tissue infections due to such a strain. All patients had been in the labour, delivery and maternity units of a small community hospital during a 7-month period. Typing by pulsed-field gel electrophoresis showed the isolates to be a single strain closely related to the USA800 lineage (paediatric clone) and additional typing confirmed it as ST5-MRSA-IV. Genes for exfoliative toxin A (ETA) and enterotoxin D were detected by PCR in all the isolates although none carried the Panton–Valentine leukocidin gene. Region-wide surveillance of over 6000 MRSA isolates collected from 1998 to 2004 showed that 95 (1·6%) were closely related to the outbreak strain although only 60 carried the ETA gene. The strain has not been seen elsewhere in Scotland.
(Accepted January 22 2009)
(Online publication March 10 2009)
This paper was presented in part at the 25th ICC/17th ECCMID, Munich, 1–3 April 2007, Poster no. 1589.