Antimicrobial therapy for two serious bacterial infections. Enterococcal endocarditis and nosocomial pneumonia.

Enterococcal endocarditis and gram-negative bacillary pneumonia are two serious infections that are particularly difficult to treat with currently available antimicrobial agents. Enterococcal endocarditis requires two drugs--a penicillin plus an aminoglycoside--to effect cure. Therapy for highly streptomycin-resistant strains seems to be particularly troublesome. The incidence of relapse and toxic reactions are high even when penicillin and gentamicin are administered for four weeks. New drugs that are less toxic are desperately needed. Nosocomial gram-negative bacillary pneumonia is associated with an extremely high mortality. However, overdiagnosis leads to the overuse of potentially toxic antimicrobial agents. Currently, therapy is usually initiated with a beta-lactam drug and an aminoglycoside, and the incidence of toxic reactions is high. New therapeutic approaches are needed.