Methicillin resistance among Trinidadian isolates of community and hospital strains of Staphylococcus aureus and their patterns of resistance to non-beta-lactam antibiotics

ABSTRACT

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains in Trinidad and the extent of their resistance to other antimicrobial agents in hospital-acquired infections were evaluated over a 2-year period. A total of 450 S. aureus strains were isolated from different patients. The prevalence of methicillin resistance among S. aureus strains was 9.8 percent (44/450). The proportion of MRSA isolated from hospital sources and community sources was 12.5 percent (38/305) and 4.1 percent (6/145) respectively (P<0.05). The resistant rates of MRSA to the non-beta-lactam antibodies were as follows 93.2 percent resistance to tetracycline, 68.2 percent to erythromycin, 61.4 percent to gentamicin, 45.5 percent to co-trimoxazole, and 20.5 percent to ciprofloxacin. No MRSA resistant to vancomycin was observed in this study. Study results showed significant increases in MRSA in hospital, 2 percent in 1995 to 12.5 percent in 1998 (P<0.05), and community, 0 percent in 1995 to 4.1 percent in 1998 (P<0.05). It has become apparent that infection must be focussed now on the community in order to monitor and limit the spread of this new and expanding reservoir of MRSA. (AU)