title: Treatment options for extended-spectrum beta-lactamase (ESBL) and AmpC-producing bacteria.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: a PGY-2 Pharmacotherapy Resident , University of Maryland School of Pharmacy , Baltimore , MD , USA.
authors.forename: Ryan G
authors.initials: RG
authors.lastname: D'Angelo
authors.affiliation: b Departments of Pathology and Epidemiology and Public Health , University of Maryland School of Medicine and Microbiology and Virology Laboratories, University of Maryland Medical Center , Baltimore , MD , USA.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Johnson
authors.affiliation: c Department of Medicine and Infectious Diseases , The Johns Hopkins Hospital , Baltimore , MD , USA.
authors.forename: Jacqueline T
authors.initials: JT
authors.lastname: Bork
authors.affiliation: d Department of Pharmacy , University of Maryland Medical Center , Baltimore , MD , USA.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Heil
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001426:Bacterial Proteins / Q000378:metabolism*; D000077723:Cefepime; D002511:Cephalosporins / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D004755:Enterobacteriaceae / Q000187:drug effects; D004756:Enterobacteriaceae Infections / Q000188:drug therapy; D006088:Gram-Negative Aerobic Bacteria / Q000187:drug effects*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D006801:Humans; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D065093:beta-Lactamase Inhibitors / Q000627:therapeutic use; D001618:beta-Lactamases / Q000378:metabolism*; D047090:beta-Lactams / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002511:Cephalosporins; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; D000077725:Piperacillin, Tazobactam Drug Combination; D000077723:Cefepime; D010397:Penicillanic Acid; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; D010878:Piperacillin
keywords: AmpC; ESBL; Enterobacteriaceae; Multidrug resistance; infectious diseases