[Evidence-based infection control methods using spa genotyping for MRSA spread in hospitals]

BACKGROUND AND OBJECTIVE: Isolation of methicillin resistant Staphylococcus aureus (MRSA) often implies rigorous infection control measures. The use of rapid and accurate typing is required to monitor their spread. Prompt identification of epidemic MRSA is crucial to control an outbreak, in order to avoid unnecessary interventions in patients and staff. In this study we evaluated protein A ( spa) gene repeat sequence analysis for MRSA typing in a hospital. METHODS: In 2003, all non-replicate MRSA-strains from staff and patients admitted to the University Hospital Münster (1480 beds), Germany, were spa typed. The spa types were assigned using the Ridom StaphType software. Typing results were correlated with the epidemiological findings of each MRSA isolate. RESULTS: Assignment of spa types was possible for all 175 MRSA isolates and provided rapid (mean, 2 days) typing results. spa typing method yielded 34 spa types. Synchronizing the sequencing results with a central database (http://www.spaServer.ridom.de) created a reproducible and uniform nomenclature for easy intra- and inter-hospital comparisons. CONCLUSION: spa typing makes continuous and fast MRSA typing possible for hospital isolates. The differentiation between outbreaks and accidental accumulations due to imported MRSA was easily possible and allowed implementation of focused and evidence-based infection control measures.