Cefepime versus extended spectrum β-lactamase-producing Enterobacteriaceae

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a growing public health concern.
• The clinical utility of cefepime in treating infections caused by these resistant bacteria remains debated.
• Recent data on cefepime susceptibility patterns in specific geographic regions is crucial for treatment guidance.

Purpose of the Study:

• To evaluate the in vitro susceptibility of a significant collection of ESBL-producing Enterobacteriaceae to cefepime.
• To analyze the prevalence of specific ESBL genes (blaCTX-M, blaTEM, blaSHV) within the studied bacterial isolates.
• To contribute data for informed decision-making regarding cefepime use in treating ESBL-producing bacterial infections.

Main Methods:

• Phenotypic characterization of 280 ESBL-producing Enterobacteriaceae strains isolated between 2005 and 2008.
• Detection and confirmation of ESBL genes (blaCTX-M, blaTEM, blaSHV) using PCR and nucleotide sequencing.
• In vitro susceptibility testing for cefepime employing disc-diffusion, agar dilution, and E-test® methods.

Main Results:

• A total of 34 isolates (12.1%) exhibited cefepime susceptibility (inhibition zone > 21 mm and MIC < 8 mg/L) via agar dilution and E-strip.
• The study identified the presence of blaCTX-M, blaTEM, and blaSHV genes in the ESBL-producing Enterobacteriaceae.
• Variability in cefepime susceptibility was observed among the tested strains.

Conclusions:

• A notable proportion of ESBL-producing Enterobacteriaceae strains demonstrated in vitro susceptibility to cefepime.
• The controversial clinical outcomes associated with cefepime in ESBL infections necessitate further investigation.
• Additional research is essential to establish definitive treatment protocols for cefepime against ESBL-producing organisms, particularly in severe infections.