Coagulase-negative staphylococci. Epidemiology, evaluation, and therapy.

More sophisticated speciation schemes and the application of a variety of epidemiology typing systems have helped to clarify the increasing frequency and changing patterns of nosocomial infections with coagulase-negative staphylococci. The presence of foreign bodies, compromised host defenses, and microbial factors such as slime production may all play important roles in the pathogenesis of these infections. Although coagulase-negative staphylococci are common contaminants in blood cultures, even a single isolation of these organisms warrants careful evaluation. Therapy of these infections may be difficult as phenotypes resistant to multiple antibiotics occur frequently. In the future, both prevention and the development of alternative antimicrobial agents will play important roles in limiting the morbidity and mortality of these infections.