ABSTRACT INTRODUCTION: Antimicrobial resistance (AMR) remains a critical global health challenge and is increasingly reported in bacteria circulating among healthy young adults. University students constitute one of the key community groups in which antibiotic misuse and environmental exposures can drive the emergence and dissemination of resistant bacteria. OBJECTIVES: This study investigated the prevalence and resistance patterns of Escherichia coli isolates circulating among university students in Southwestern Nigeria, with a focus on multidrug resistance (MDR) and extended-spectrum β-lactamase (ESBL) production in these bacteria. METHODS: A cross-sectional study was conducted among 200 volunteer undergraduate students. Standard microbiological methods were used for the collection, purification, and identification of fecal E. coli isolates, followed by antimicrobial susceptibility testing according to established protocols. ESBL production was phenotypically screened and genotypically confirmed by polymerase chain reaction (PCR) targeting bla TEM , bla SHV , and bla CTX-M genes. Potential behavioral and environmental risk factors for carriage of MDR bacteria by students were assessed using structured questionnaires. Descriptive and inferential statistical analyses were performed, with a significance threshold of p < 0.05. RESULTS: A total of 350 E. coli isolates were recovered from 186 students. Resistance to tetracycline was the most prevalent (90.6%) among E. coli isolates, whereas meropenem exhibited the lowest resistance rate (2.8%). Overall, 84.9% of the isolates demonstrated multidrug resistance. Twenty isolates (5.7%) were phenotypically identified as ESBL producers, and 18 (5.1%) harbored at least one of the target genes. Carriage of MDR E. coli by university students was significantly associated with self-medication, while the use of well or rainwater as drinking sources was significantly associated with carriage of ESBL-producing bacteria (p < 0.05). CONCLUSION: This study demonstrates high burden of AMR among commensal E. coli isolates from university students, particularly resistance to tetracycline. The circulation of MDR and ESBL-producing strains among students highlights the combined influence of their inappropriate antibiotic use and environmental exposure. Strengthened AMR education, antibiotic regulation, and water and sanitation infrastructure within university settings is essential to limit the spread of bacterial resistance.
Adeniyi et al. (Thu,) studied this question.