Impact of Gram-positive resistance on outcome of nosocomial pneumonia

Among Gram-positive pathogens, Staphylococcus aureus is the leading cause o f death from nosocomial pneumonia, The bacterium developed progressive resi stance to beta -lactams, and methicillin-resistant strains emerged in the 1 980s, In consequence, vancomycin has become the drug of choice for treatmen t of this infection over the last decade, based on susceptibility tests and the serum antimicrobial levels recorded, However, half of the patients tre ated with vancomycin have died. In contrast, in patients receiving beta -la ctams for pneumonia caused by methicillin-sensitive S, aureus, survival is the rule. These observations, together with the emergence of isolates with reduced susceptibility to glycopeptides, raised concern about the use of va ncomycin as standard therapy for pneumonia caused by Gram-positive cocci. M aintaining tissue levels above minimal inhibitory concentration is vital to successful clinical outcome, Optimizing treatment focusing on this goal an d new antimicrobials provide new opportunities to improve survival.