The predominant variant of the Brazilian epidemic clonal complex of methicillin-resistant Staphylococcus aureus has an enhanced ability to produce biofilm and to adhere to and invade airway epithelial cells

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a therapeutic problem. In the present study, the molecular characterization by pulsed-field gel electrophoresis of MRSA isolates collected from a university hospital revealed that the predominant variant of the Brazilian epidemic clonal complex (BECC) was responsible for the increase in the incidence of MRSA strains, which reached 28% in 1998. It was verified that this predominant variant of the BECC displayed an enhanced ability to produce biofilm on inert polystyrene surfaces and to adhere to and invade epithelial airway cells. These results indicate that MRSA strains belonging to the BECC have evolved advantageous properties that might play a role in their predominance as international nosocomial pathogens.