Trends in beta-lactam resistance among Enterobacteriaceae

Area of Science:

• Microbiology
• Molecular Biology
• Antimicrobial Resistance

Background:

• Beta-lactam resistance in Enterobacteriaceae is a growing global health concern.
• This resistance is primarily mediated by the emergence of diverse beta-lactamase enzymes.
• Understanding these enzymes is critical for effective treatment strategies.

Purpose of the Study:

• To review and categorize the various beta-lactamase enzymes contributing to Enterobacteriaceae resistance.
• To highlight the mechanisms of action and inhibition profiles of different beta-lactamase classes.
• To provide an overview of the global incidence of these resistance mechanisms.

Main Methods:

• Literature review and synthesis of existing data on beta-lactamase characterization.
• Classification of beta-lactamases based on enzyme class, substrate hydrolysis, and inhibitor susceptibility.
• Analysis of geographical distribution and host organism prevalence for specific beta-lactamases.

Main Results:

• Extended-spectrum beta-lactamases (ESBLs) are divided into TEM, SHV, and other groups (e.g., CTX-M, PER-1).
• Plasmid-mediated cephalosporinases (e.g., CMY-2, LAT-1) hydrolyze cephalosporins and cephamycins, unaffected by clavulanic acid.
• Carbapenemases include chromosomally located (e.g., Sme-1) and plasmid-mediated (e.g., IMP-1) types, with IMP-1 prevalent in Japan.

Conclusions:

• The emergence of novel beta-lactamases is the primary driver of beta-lactam resistance in Enterobacteriaceae.
• Diverse beta-lactamase types confer resistance through different hydrolysis and inhibition patterns.
• The increasing incidence of these resistance mechanisms worldwide necessitates ongoing surveillance and intervention.