Methicillin-resistant Staphylococcus aureus.

Out of 308 isolates of Staphylococcus aureus isolated from specimens processed at the Department of Microbiology, Faculty of Medicine, Colombo 66 (21.5%) were resistant to methicillin. A significantly higher proportion of methicillin resistant Staphylococcus aureus (MRSA) were isolated from special care units, namely the Premature Baby Unit (PBU) and the Plastic Surgery Unit (PSU) when compared with other general medical and surgical units. Most of these strains were also resistant to many other antibiotics. The patients with MRSA infections had a longer mean hospital stay when compared to patients with methicillin sensitive Staphylococcus aureus (MSSA) infections. MRSA strains are as virulent as MSSA strains and these infections are mainly nosocomial.