Molecular Characterization of Diarrhoeagenic Escherichia coli Pathotypes Isolated from Under Five Years Children in Katsina State

Background and Objective: Diarrhoea, majorly caused by diarrhoeagenic Escherichia coli (DEC) is the second leading cause of death in children globally, particularly in developing countries like Nigeria.The study molecularly characterized diarrhoeagenic Escherichia coli pathotypes isolated from children under five years in Katsina State.Materials and Methods: A total of 165 stool samples were collected from 135 (diarrheic) and 30 (non-diarrheic) children attending five selected hospitals in Katsina State, within a period of nine months, from October, 2021 to June, 2022.The samples were screened for diarrhoeagenic E. coli pathotypes using uniplex and multiplex conventional PCRs.Specific primers were used for the detection of seven virulence genes (eae, stx1, stx2, est, elt, aggR and ipaH genes), respectively, which are peculiar to the DEC strains.Results: Of 165 stool samples examined, 40 (57.97%)tested positive for DEC.Enteroaggregative E. coli (EAEC) was found to be the most frequently encountered pathotype (36.23%) followed by enteropathogenic E. coli (EPEC, 8.69%) then enteroinvasive E. coli (EIEC, 7.25%) and enterotoxigenic E. coli (ETEC) which was the pathotype that least prevailed among the study population (5.79%).Conclusion: The findings of this study revealed that enteroaggregative E. coli (EAEC) and enteropathogenic E. coli (EPEC) are the most circulating DEC pathotypes among children under the age of five years in Katsina State.