Introduction

The spa gene encodes protein A and is used for typing of methicillin-resistant Staphylococcus aureus, MRSA, such as the mec operon carried by staphylococcal cassette chromosome (SCCmec).

Objectives

The aim of this study was the molecular typing of MRSA isolated from different forms of infections for epidemiological purposes using spa typing method and SCCmec classification.

Methods

A total of 90 MRSA isolates coming from eight hospitals from southern Poland were tested. Isolates originated from: bloodstream and respiratory tract infections (36), surgical site infections (30), chronic wounds (24). S pa typing was performed as described previously [1], using the spa typing website (http://www.spaserver.ridom.de/). Staphylococcal cassette chromosome mec (SCC mec) typing was performed as described previously [2].

Results

The majority of MRSA strains were of SCCmec type II (42.2%) or SCCmec IV (21.1%). Eleven strains was marked as SCCmec III (12.2%), 8 as SCCmec V (8.9%), 4 as SCCmec I (4.4%) and one as SCCmec VI.

The spa type t003 was the most frequently observed (37.8% of strains), then t138 (14.4%), t008 and t037 and t041 (4.4%),

SCC mec type II and spa-t003 together were characteristic for 25% of the chronic wounds and 27% in SSI, but 39% in invasive infections.

SCCmec III and t138 occurred in 10% of the strains from two hospitals, SCCmecIV and t003 occurred in 6.7% strains from two hospitals.

Conclusion

Epidemiological and molecular studies of MRSA isolates allowed to detail insight into the problem of staphylococcal infections. Those methods are less time-consuming than PFGE and give the opportunity for the observation of the current situation and epidemiological trends for resistant strains on the level of ward/hospital or even whole region (supported by a grant DEC-2011/03/B/NZ7/01911).