Beta-lactamases are bacterial enzymes that hydrolyze the beta-lactam ring of penicillins, cephalosporins, and carbapenems, rendering them inactive. They are the most common mechanism of antibiotic resistance and a central concern in the antimicrobial resistance crisis. Extended-spectrum beta-lactamases (ESBLs) and carbapenemases (KPC, NDM, OXA-48) confer resistance to last-resort antibiotics.
Co-Selection with Metal Resistance
Beta-lactamase genes frequently co-locate with metal resistance genes on the same plasmids and mobile genetic elements — meaning environmental metal exposure selects for beta-lactamase-producing bacteria without antibiotic exposure baker austin 2006 co selection antibiotic metal resistance srivastava 2016 environmental resistance microbes review. This is documented in CKD gut microbiome miranda 2022 metalloids antibiotic resistance ckd gut.
WikiBiome Relevance
The beta-lactamase → co selection → metal resistance connection is a core WikiBiome insight: heavy metal pollution in agriculture, water, and food is an unrecognized driver of antibiotic resistance in the human gut microbiome.
Cross-References
- antimicrobial resistance — AMR context
- co selection — metal-antibiotic co-resistance on shared plasmids
- cephalosporin — beta-lactam antibiotic class
- vancomycin — alternative when beta-lactams fail
- klebsiella — major carbapenemase-producing genus