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

ABSTRACT

Introduction: Extended spectrum β-lactamases (ESBL) and AmpC β-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 β-lactam-β-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 β-lactamases, which further create confidence in the use FEP in these situations. Patient and infection specific characteristics should be used to employ FEP optimally.

KEYWORDS:

• Multidrug resistance
• infectious diseases
• Enterobacteriaceae
• ESBL
• AmpC

Article highlights

• Carbapenem antimicrobials have emerged as first-line therapy for ESBL and AmpC-producing Enterobacteriaceae. Due to concerns of increasing carbapenem resistance, interest in the use of carbepenem-sparing agents has recently increased.

• With different resistance profiles of ESBL and AmpC β-lactamases, certain β-lactam agents may have successful use in certain clinical situations.

• β-lactam β-lactamase inhibitor agents such as PTZ have displayed conflicting success in the treatment of ESBL-producing Enterobacteriaceae dependent on site of and severity of infection.

• FEP has been found to have similar clinical success to carbapenems in patients with infection with AmpC β-lactamase-producing organisms; however, greater success is seen in low inoculum infections such as urinary and biliary tract infections.

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.