DETECTION OF FAECAL CARRIAGE OF AMPC Β-LACTAMASEPRODUCERS AMONG EXTENDED SPECTRUM BETA-LACTAMASE-PRODUCING ESCHERICHIACOLI IN PATIENTS ATTENDING FAITH ALIVE FOUNDATION HOSPITAL JOS

ABSTRACT Antimicrobial resistance caused by β-lactamase–producing organisms poses a major global health challenge. This study investigated the prevalence of faecal carriage of AmpC β-lactamase producers among ESBL-producing Escherichia coli isolated from patients attending Faith Alive Foundation Hospital, Jos. A cross-sectional study design was adopted. Fresh stool samples were aseptically collected from patients and cultured on MacConkey and Eosin Methylene Blue (EMB) agar. Isolates were identified using standard biochemical tests. ESBL production was detected using the double-disc synergy test (DDST), while AmpC β-lactamase production was confirmed by the inhibitor-based disk method employing cefoxitin and boronic acid. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method in accordance with CLSI guidelines.A high prevalence of ESBL-producing E. coli was observed, indicating widespread β-lactam resistance among enteric isolates. Among these, a significant proportion co-produced AmpC β-lactamase, suggesting possible plasmid-mediated coexistence of multiple resistance genes. The isolates displayed marked multidrug resistance, showing reduced susceptibility to third-generation cephalosporins and β-lactam/β-lactamase inhibitor combinations, although carbapenems such as imipenem and meropenem remained highly effective. The coexistence of ESBL and AmpC β-lactamases in E. coli is of clinical concern, as it may lead to treatment failure and increased transmission risk.This study emphasizes the need for routine screening of AmpC β-lactamase among ESBL producers to ensure accurate diagnosis and appropriate therapy. Continuous antimicrobial surveillance, enforcement of antibiotic stewardship programs, and strengthening of infection control measures are urgently required to limit the spread of multidrug-resistant E. coli strains in both hospital and community settings