Campylobacter jejuni is a zoonotic pathogen transmitted through the "farm to fork" route. Outbreaks are generally associated with the consumption of chicken meat; however, dairy cows, birds, wild and domestic food animals, and pets are other important sources. Currently, there are not enough data comparing the virulence of strains isolated from these reservoirs. In this study, we compared C. jejuni strains isolated from broiler chickens and dairy cattle by determining their ability to adhere to and invade in vitro human colonic epithelial cells in the T84 cell line with their motility, formation of biofilms, and presence of eight virulence genes. A Wilcoxon Rank Sum test was performed to establish the relationship between presence of the studied genes and cellular invasion and adhesion, as well as differences between the animal species of origin of the isolate. A Spearman correlation was performed to assess the relationship between invasion and motility, along with invasion and biofilm generation. The virB11 gene was positively associated with the adherence capacity of the strains (mean difference = 0.21, p = 0.006), and strains isolated from chickens showed a significant difference for adherence compared with strains isolated from cattle (p = 0.0001). Our results indicate that strains of C. jejuni have a difference in their adherence capacity depending on the animal reservoir from which they came, with chicken isolates displaying higher virulence than dairy cattle isolates.
Keywords: adhesion; adhérence; invasion; virulence; zoonoses.