Prevalence and molecular characterisation of campylobacter species in chickens and children under the age of five years in Zimbabwe

Abstract

Introduction: Campylobacter species are a major cause of foodborne infections worldwide.
Objective: To determine the antimicrobial susceptibility patterns and prevalence of virulence genes of Campylobacter species isolated from chickens and children under the age of five in Zimbabwe.
Design, Setting and Subjects: A cross-sectional study with 189 chicken rectal swabs collected from a distributor chicken farm in the month of August 2020and 126 human stool samples from children under the age of 5 years presenting with diarrhoea attending Parirenyatwa group of Hospitals, a central referral hospital and two private laboratories between June and November 2020in Harare. DNA was extracted using the boiling method, and Polymerase Chain Reaction (PCR) was employed to screen for target genes in the isolates.
Results: Overall, 18.3% (23/126) of the children specimens were positive for Campylobacter, of which 78.3% were C. jejuni and 21.7% were C. coli. The prevalence of Campylobacter in chickens was 23.8% (45/189), of which 76.9% were C. jejuni and 23.1% were C. coli. The isolates showed a wide variation in the presence of the virulence genes with notable high prevalence in the detection of cadF, flaA and the cdt genes. In children, the prevalence of the virulence genes; cadF, cdtA, cdtC, dnaJ, flaA, ciaB , and cdtB were 91.3%, 82.6%, 73.9%, 69.6%, 65.2%,47.8%, and 34.8%respectively. In chickens, the prevalence of the virulence genes; cdtA, cdtC cadF, cdtB, flaA, dnaJ, and ciaB were 97.4%, 89.7%, 82.1%, 82.1%, 66.7%, 59.0%, and 30.1%, respectively.
Conclusion: This study revealed a higher prevalence of Campylobacter in children than previously reported locally and a moderate prevalence in chickens, with widespread virulence genes and high resistance to multiple antibiotics, underscoring the urgent need for strengthened public health, food safety, and antimicrobial stewardship measures to mitigate zoonotic transmission.