Treatment options for extended-spectrum beta-lactamase (ESBL) and AmpC-producing bacteria

Introduction: Extended spectrum beta-lactamases (ESBL) and AmpC beta-lactamases are increasing causes of resistance in many Gram-negative pathogens of common infections. This has led to a growing utilization of broad spectrum antibiotics, most predominately the carbapenem agents. As the prevalence of ESBL and AmpC-producing isolates and carbapenem resistance has increased, interest in effective alternatives for the management of these infections has also developed. Areas covered: This article summarizes clinical literature evaluating the utility of carbapenem-sparing regimens for the treatment of ESBL and AmpC-producing Enterobacteriaceae, mainly beta-lactam-beta-lactamase inhibitor combinations and cefepime (FEP). Expert opinion: Based on available data, the use of piperacillin-tazobactam (PTZ) and FEP in the treatment of ESBL-producing Enterobacteriaceae cannot be widely recommended. However, certain infections and patient characteristics may support for effective use of these alternative agents. In the treatment of infections caused by AmpC-producing Enterobacteriaceae, FEP has been shown to be a clinically useful carbapenem-sparing alternative. Carbapenems and FEP share many structurally similar characteristics in regards to susceptibility to AmpC beta-lactamases, which further create confidence in the use FEP in these situations. Patient and infection specific characteristics should be used to employ FEP optimally.