UK epidemic strains of meticillin-resistant Staphylococcus aureus in clinical samples from Malta

1 School of Life Sciences, Kingston University, Kingston-upon-Thames KT1 2EE, UK 2 School of Life and Health Sciences, University of Aston, Birmingham B4 7ET, UK 3 Department of Microbiology, St. Luke's Hospital, Malta 4 Department of Statutory and Exotic Bacterial Diseases, Veterinary Laboratories Agency (Weybridge), Woodham Lane, Addlestone, Surrey KT15 3NB, UK Correspondence Mark D. Fielder m.fielder{at}kingston.ac.uk Received May 14, 2008 Accepted July 28, 2008 Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has monitored the rise in infection due to a number of organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The EARSS reported that MRSA infections within intensive care units account for 25–50 % of infections in many central and southern European countries, these included France, Spain, Great Britain, Malta, Greece and Italy. Each country has defined epidemic MRSA (EMRSA) strains; however, the method of spread of these strains from one country to another is unknown. In this current study, DNA profiles of 473 isolates of MRSA collected from the UK and Malta were determined by PFGE. Analysis of the data showed that two countries separated by a large geographical distance had a similar DNA profile pattern. Additionally it was demonstrated that strains of EMRSA normally found in the UK were also found in the Maltese cohort (EMRSA 15 and 16). A distinct DNA profile was found in the Maltese cohort, which may be a local EMRSA, and accounted for 14.4 % of all Maltese isolates. The appearance of the same MRSA and EMRSA profiles in two separate countries suggests that MRSA can be transferred out of their country of origin and potentially establish in a new locality or country. Abbreviations: EARSS, European Antimicrobial Resistance Surveillance System; EMRSA, epidemic meticillin-resistant Staphylococcus aureus ; EU, European Union; LBH, London-based hospitals; MAR, multiple antibiotic resistance; MRSA, meticillin-resistant Staphylococcus aureus .