ANTIMICROBIAL RESISTANCE IN ESCHERICHIA COLI ISOLATED FROM DIARRHOEAL PATIENTS IN NAKIVALE REFUGEE SETTLEMENT, SOUTHWESTERN UGANDA

Abstract

Background Antimicrobial resistance (AMR) is a critical global health crisis, particularly in resource-limited refugee settlements where high population density and inadequate sanitation facilitate the spread of resistant pathogens. This study aimed to determine the prevalence, antimicrobial resistance patterns, and extended-spectrum beta-lactamase (ESBL) genotypes of Escherichia coli among patients with diarrhea in the Nakivale Refugee Settlement, Southwestern Uganda. Methods A cross-sectional study was conducted between January and May 2024 at Nakivale Health Centre III, involving 197 patients presenting with diarrheal symptoms. E. coli isolates were identified using culture, biochemical tests, and MALDI-TOF MS. Pathogenic strains (serogroup O157) were identified via latex agglutination. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method, and ESBL-encoding genes (bla-TEM, bla-CTX-M, and bla-SHV) were detected using polymerase chain reaction. Results E. coli was recovered from 28.9% (57/197) of participants, with the highest recovery rate in children under 13 years (43.6%; p=0.013) and those using open surface water (44.0%; p<0.001). Of the isolates, 72% (41/57) were presumptive pathogenic serogroup O157. These isolates exhibited high resistance to trimethoprim (92.68%), tetracycline (90.24%), and ampicillin (82.93%). Susceptibility remained high for ceftazidime (92.68%). Genotypic analysis of 33 selected isolates revealed a high prevalence of ESBL genes: bla-TEM (96.96%), bla-CTX-M (87.87%), and bla-SHV (45.45%), with 39.39% of isolates concurrently carrying all three genes. Conclusion There is a high burden of multidrug-resistant and ESBL-producing E. coli in the Nakivale Refugee Settlement, driven by the dominance of bla-TEM and bla-CTX-M genes. The strong association between surface water use and infection underscores the urgent need for improved sanitation infrastructure and enhanced antimicrobial stewardship to preserve the efficacy of remaining treatments in displaced populations.