Extended-spectrum beta-lactamases. An overview.

The emergence of extended-spectrum beta-lactamase (ESBL)- producing Klebsiella pneumoniae and other ESBL-producing Enterobacteriaceae is an increasing problem and presents a dilemma for clinicians. The problem is not only detection of this resistance in the microbiology laboratory, but also a therapeutic dilemma due to multiple drug resistance to extended-spectrum beta-lactams and other agents, including fluoroquinolones, trimethoprim-sulfamethoxazole, and gentamicin. Currently, imipenem appears to be the drug of choice for serious infections due to these isolates, based on accumulating clinical experience. Because options for therapy are limited, control and prevention measures are particularly important. These should include not only traditional infection control measures such as contact precautions, but also antibiotic utilization measures, such as widespread empiric use of ceftazidime.