Extended-spectrum beta-lactamases

The Enterobacteriaceae may produce extended-spectrum beta-lactamases (ESBLs). These enzymes can destroy most beta-lactam antibiotics and lead to multi-drug resistance. The treatment of choice of ESBL-producing organisms is usually an antibiotic of the carbapenem class. Unfortunately, another beta-lactamase type, the KPC beta-lactamases are now occurring in some areas and are responsible for resistance to carbapenems.