Distribution of meticillin-resistant Staphylococcus aureus spa types isolated from health-care workers and patients in a Scottish university teaching hospital

Our study was aimed at comparing the meticillin-resistant Staphylococcus aureus (MRSA) strains isolated from an anonymous group of health-care workers (HCWs) with those obtained from patient samples during a 3-month time interval. We employed spa typing and virulence gene profiling to characterize the MRSA strains. Our data revealed that a total of 14 discrete spa types were circulating in both patients and HCWs. The t032 spa type, characteristic of EMRSA15 and the Barnim EMRSA ST 22 clones, accounted for over 70% of isolates, and was equally distributed between patients and HCW groups. In addition, a number of epidemic and sporadic strains were identified, which highlighted the diversity of spa types that can be found within a health-care setting. Virulence profiling for the carriage of 7 genes by the 14 different spa types demonstrated that 10 types carried the fnbA, cna, sdrE, hlg and ica virulence factors. We concluded that there was no significant difference between the MRSA strains found circulating in the patients and the HCWs, and noted that the dominant spa types carried an identical set of virulence genes that included the key adhesins fnbA, cna and sdrE.