Evolution of methicillin-resistant Staphylococcus aureus isolated at a community healthcare centre in Spain
Abstract number: P1040
Potel C., Álvarez M., Constenla L., Lago F., Varela C.
Objective: To determine the distribution of Methicillin-Resistant Staphylococcus aureus (MRSA) isolated from outpatients at a community health care center serving a large population of 300.000 from the Northwest of Spain.
Methods: In total 1.913 S. aureus were isolated between 2003 and 2007. From these ones, 135 strains were MRSA.
The presence of mecA gene and pvl genes was identified in all MRSA strains by PCR. The isolates were studied by analysis of restriction fragment length polymorphism of the coagulase gene and digestion with cfoI (RFLP) and pulsed-field gel electrophoresis (PFGE). The staphylococcal chromosome cassette (SCC)mec and the accessory gene regulator (agr) types were determined by multiplex and duplex PCR respectively. Representative strains were analyzed by spa typing and multilocus sequence typing (MLST).
Results: The MRSA percentage ranged from 9% in 2003 to 12% in 2007. According to the RFLP patterns, the 135 MRSA isolates were classified in seven clonal groups; 33.4% were identified as t018-ST36-II-agr1 (British clone); 30% t002-ST5-IV-agr2 (New York/Japan clone); 25% t067-ST125-IV-agr2 or IVa-agr2; 4.5% t148-ST72-IVa-agr1; 4.5% t037-ST239-II-agr3 (Brazilian clone); 1.5% t008-ST8-IV-agr1 (USA300 clone); 0.8% t002-ST5-IV-agr1 (Paediatric clone).
The pvl genes were detected in four isolates (3%); two strains belonged to the USA300 clone (one was isolated in 2006 and the other in 2007), one strain to the Paediatric clone, and another one to the ST125 clone.
Conclusion: In other surveillance studies, we described the local epidemic lineages isolated in the hospital setting (1, 2). They were typically health-care associated clones; ST36 (actually it is endemic in our hospitals), ST5, ST125, and ST239 (it was endemic until 2002). In the present study these clones were isolated in outpatients, therefore they were also circulating in the community setting. The clones denominated as community-acquired MRSA were scarcely isolated, only two USA300 isolates. We can state that the community setting highlights the relationship between community and hospital MRSA strains whichever might have been their acquisition, so we think that it is useful to continue surveillance in this scenario.
|Session name:||Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Vienna, Austria, 10 - 13 April 2010|
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