RISK FACTORS ASSOCIATED WITH MULTIDRUG-RESISTANT ESCHERICHIACOLI O157:H7 ISOLATED FROM STOOL SAMPLES OF PATIENTS PRESENTINGWITH GASTROENTERITIS

Abstract

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is a significant aetiological agent of diarrhoeal diseases,
causing illnesses ranging from mild diarrhoea to severe conditions such as haemorrhagic colitis and haemolytic
uremic syndrome (HUS), which has not been widely documented in Nigeria. This study investigated the prevalence
and antibiotic susceptibility patterns of Escherichia coli and E. coli O157:H7, isolated from stool samples of patients
attending the Ahmadu Bello University Medical Center in Zaria, Nigeria. A total of 100 stool samples were collected
from consenting patients and analyzed using standard microbiological techniques. Identification of isolates was
based on cultural, microscopic, and biochemical characteristics. Antibiotic susceptibility testing was performed
using the Kirby-Bauer disc diffusion method. Out of the 100 samples, 25% were positive for E. coli. Of these, three
were confirmed as E. coli O157:H7, resulting in a prevalence rate of 3% for this strain. Socio-demographic analysis
showed a higher infection among patients aged 10–25 years. Although, there was no statistically significant
association between the prevalence of the infection and the risk factors assessed in the study (p >0.05), there was
increased risk of the infection in patients who kept pets (26.8%;19/71), exposed to livestock and their wastes
(26.7%:8/30) and eating of raw vegetables (26.8%;19/71). Antibiotic susceptibility results revealed a high level of
resistance to Amoxicillin-Clavulanic acid (95%). These findings emphasize the urgent need for ongoing surveillance
of E. coli infections and their resistance profiles to guide effective treatment and public health strategies in the
region.