Types of methicillin-resistant Staphylococcus aureus associated with high mortality in patients with bacteremia

Forty-seven strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from 47 patients with bacteremia were analyzed by chromosomal DNA digestion pattern using pulsed-field gel electrophoresis and evaluated for serological coagulase type, enterotoxin type, and toxic shock syndrome toxin-l production. The mortality rate was significantly higher in the older patients (greater than or equal to 51 years of age) than in the younger patients (less than or equal to 50 years of age) (50% vs. 4%, p=0.0007). Methicillin-resistant Staphylococcus aureus strains of serological coagulase type II were more likely to be associated with mortality in older patients than were strains of the other types (p=0.037).