Global epidemiology of antimicrobial resistance among community-acquired and nosocomial pathogens: a five-year summary from the SENTRY Antimicrobial Surveillance Program (1997-2001).

Resistance to antimicrobial agents among clinically important pathogens in the community and hospital settings has compromised therapy and requires constant monitoring of emerging patterns. Although local information indexed by hospital service or ward remains preferred, the initiation of several comprehensive surveillance programs (SENTRY Antimicrobial Surveillance Program, MYSTIC Programme, ICARE, EARSS, etc.) offers quality susceptibility testing results to guide empirical treatment regimens. Enterococci and staphylococci with novel resistance mechanisms to glycopeptides (vancomycin, teicoplanin) require greater use of quinupristin/dalfopristin and linezolid. For streptococci, recent modifications of laboratory interpretive criteria for cefotaxime, ceftriaxone, and cefepime indicates that coverage remains at > or = 95%. Extended-spectrum beta-lactamases in Enterobacteriaceae and multidrug resistance in Acinetobacter spp. and Pseudomonas aeruginosa most challenge our choices of effective agents for nosocomial infections. Few new drugs have surfaced for therapy of these gram-negative bacilli, and two- or three-agent combination regimens may be required with greater frequency, especially to cover the more prevalent resistances among both gram-positive cocci and gram-negative nonfermentative rods.