The Importance of β -Lactamase Resistance in Surgical Infections

Substantial costs are associated with the treatment of nosocomial infections, 2 million cases of which occur annually in the United States. Hospital-acquired, gram-negative infection has become an increasing problem, particularly in the intensive care unit where up to 40% of the most frequently isolated strains of Enterobacteriaceae are resistant to standard beta-lactam antibiotics. Among several mechanisms of acquisition of resistance, beta-lactamase production accounts for a high percentage of treatment failures and relapses. By the end of the 1980s, some 10-30% of all nosocomial infections were caused by type-1 beta-lactamase-producing gram-negative isolates, and Enterobacter species had emerged as a major resistant pathogen. The beta-lactam/beta-lactamase inhibitor combinations, such as ampicillin/sulbactam, represent an innovative approach to the problem of beta-lactamase-mediated resistance. Clinical use of these agents has been associated with low rates of resistance and new data suggest they may have a specific role in controlling the emergence and spread of nosocomial infections.