Prevalence, molecular detection, and virulence gene profiles of Campylobacter species in humans and foods of animal origin

Abstract

Background and Aim: Campylobacteriosis is one of the most well-characterized bacterial foodborne infections worldwide that arise chiefly due to the consumption of foods of animal origin such as poultry, milk, and their products. The disease is caused by numerous species within the genus Campylobacter, but Campylobacter jejuni is the most commonly isolated species from established cases of human campylobacteriosis. This study was conducted to determine the prevalence and virulence of Campylobacter isolates from human, chicken, and milk and milk products in Egypt. Materials and Methods: A total of 1299 samples (547 chicken intestine and liver, 647 milk and milk products, and 105 human stool) were collected and microbiologically investigated, confirmed by multiplex polymerase chain reaction (PCR) targeting the 23S rRNA, hipO, and glyA genes specific for Campylobacter spp., C. jejuni, and Campylobacter Coli, respectively, followed by virulence genes (Campylobacter adhesion to fibronectin F [cadF] and cdtB) detection using PCR. Results: About 38.09%, 37.84%, and 8.5% of human stool, chicken, and milk and milk product samples, respectively, were bacteriologically positive, with a total of 302 Campylobacter isolates. All isolates were molecularly confirmed as Campylobacter spp. (100%) where 285 isolates (94.37%) were identified as C. jejuni and 17 isolates (5.62%) as C. coli. Regarding the virulence pattern, all isolates (100%) carried cadF gene while cytolethal distending toxin B gene was definite in 284/302 isolates (94%), concisely, 282/285 (98.94%) C. jejuni isolates, and in 2/17 (11.76%) C. coli isolates. Conclusion: The widespread presence of these highly virulent Campylobacter, especially C. jejuni, proofs the urgent need for the implementation of stringent control, public health, and food protection strategies to protect consumers from this zoonotic pathogen. The availability of information about pathogen virulence will enable enhanced local policy drafting by food safety and public health officials.