VOLUME 18 (Supplement)

Phenotypic expression of biofilm formation and ESBL-linked resistance in Escherichia coli isolated from meat

Biofilm-mediated bacterial persistence is a key factor of antimicrobial resistance, facilitating prolonged survival and eventually contributing to therapeutic failure in clinical infections. This study reports the isolation of a putative extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, with the phenotypic co-expression of biofilm production, from commercially-sold meat, highlighting the potential risk posed by virulent foodborne pathogens. Phenotypic assays confirmed ESBL activity through penicillin hydrolysis and modified double-disc synergy, while PCR amplification and sequencing identified the presence of bla genes conferring β-lactamase production. Biofilm-forming capacity was observed using the crystal violet assay. Antimicrobial susceptibility testing revealed extensive drug resistance including phenotypic markers for both AmpC and ESBL production. Notably, the isolate exhibited co-expression of ESBL production and biofilm formation, indicating a dual mechanism of resistance and persistence. The coexistence of these virulence factors in a foodborne strain underscores a heightened public health risk, with implications for both clinical treatment outcomes and food safety monitoring.