Asian Journal of Immunology

Antimicrobial resistance among healthcare-associated pathogens remains a major challenge, particularly among long-term hospitalised patients who are frequently exposed to antimicrobial therapy and healthcare environments. This study investigated the prevalence, antibiotic resistance patterns, plasmid profiles, and beta-lactamase resistance genes of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolated from long-term hospitalised patients in selected tertiary hospitals in Enugu State, southeastern Nigeria. A hospital-based cross-sectional study was conducted among 204 patients hospitalised for 14 days or longer. Urine and wound samples were collected and analysed using standard microbiological procedures. E. coli isolates were identified by culture and biochemical methods, ESBL production was detected using Chromatic ESBL agar, antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method, and plasmid profiling and detection of blaTEM, blaSHV, and blaCTX-M genes were conducted using molecular techniques. Among the 204 clinical samples analysed, E. coli was isolated from 16/204 samples (7.8%), while ESBL-producing E. coli was detected in 10/204 samples (4.9%). ESBL-producing isolates were recovered mainly from urine samples (6/204, 2.9%) and diabetic wound ulcer samples (3/204, 1.5%). The E. coli isolates demonstrated high resistance to tested antibiotics, including complete resistance to several commonly used agents. Plasmid analysis showed that all 10 ESBL-producing isolates carried plasmids, while molecular analysis detected blaTEM in 10/10 isolates (100%) and blaCTX-M in 8/10 isolates (80%); blaSHV was not detected. The detection of plasmid-mediated ESBL-producing E. coli among long-term hospitalised patients highlights the need for continuous antimicrobial resistance surveillance, strengthened infection prevention practices, and effective antimicrobial stewardship programmes in healthcare facilities.