Genotyping of Meticillin-resistant Staphylococcus aureus Outbreak Isolates / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate characters of molecular epidemiology of meticillin-resistant Staphylococcus aureus(MRSA) outbreak strains in an emergency intensive care unit(EICU),to follow-up the possible sources,understand transmission for infection,and determine preventive strategies.METHODS Pulsed-field gel electrophoresis(PFGE) was used to analyze the homology of MRSA strains,isolated from clinical patients′ infection sites and environment,and carried by patients and healthcare workers in EICU of our hospital in December,2004.RESULTS Six of 17 patients were infected by MRSA,and 7 strains were isolated((including) 2 strains from different sites of the same patient).Surveillance cultures of ward′s environments,(patients)′ nares and healthcare workers′ nares and hands were performed in the outbreak period.Five MRSA strains were isolated,including a strain from nares of a patient,a strain from a table-board of a procedure room,a strain from hand of a nurse,a strain from a bed bar,and a strain from ward′s air.PFGE typing of the 12 MRSA strains showed that all 7 strains isolated from patients′ infection sites and two strains from nares of a patient and hand of a nurse were of type A.Strains from a procedure room,bed bar and air were of types B,C and D,respectively.CONCLUSIONS MRSA′s source and its transmission route are elucidated by genotyping.MRSA appears to come from a patient′s nares and has been transferred in ward by hand of healthcare workers.