Campylobacter spp. prevalence and mitigation strategies in the broiler production chain.

This study aims to discuss the microbial ecology of the broiler gut environment, Campylobacter prevalence across the broiler production chain with a follow-up focus on a possible mitigation strategy, based on the use of bacteriophages. Scientific literature published from the last two decades was reviewed and data were collected to establish the ranges of Campylobacter loads from different samples. Results showed that the pathogen load in the sample is likely to increase from the different stages of the production chain. Contamination of water and feed represents the most notable source of contamination during the primary production, while cross-contamination of broiler carcasses, skin, and meat occurs during the slaughter, dressing, and processing via machinery, work surfaces, water, and air partially due to the leaking of contaminated feces from visceral rupture. Knowledge gaps were identified and included: a lack of studies detecting Campylobacter in broilers in most of the European countries over the last decade and a low number of studies determining the bacterial load in crates used to transport broilers to the slaughterhouse. Determining the prevalence of Campylobacter in the broiler industry will enable us to set critical control points to produce broiler flocks and meat products with a low risk of Campylobacter contamination.

The Minor Flagellin of Campylobacter jejuni (FlaB) Confers Defensive Properties against Bacteriophage Infection.

A screen of bacteriophages infecting a panel of Campylobacter jejuni PT14 gene knock-out mutants identified a role for the minor flagellin encoded by the flaB gene, in the defense of the host against CP8unalikevirus bacteriophage CP_F1 infection. Inactivation of the flaB gene resulted in an increase in the susceptibility of PT14 cultures to infection by CP_F1 and an increase in bacteriophage yields. Infection of wild type PT14 with CP_F1 produces turbid plaques in bacterial lawns, from which 78% of the resistant isolates recovered exhibit either attenuation or complete loss of motility. CP_F1 produces clear plaques on the flaB mutant with no regrowth in the lysis zones. Complementation of the mutant restored overgrowth and the development of resistance at the expense of motility. Further analyses revealed an increase in bacteriophage adsorption constant of nearly 2-fold and burst-size 3-fold, relative to the wild type. Motility analysis showed no major reduction in swarming motility in the flaB mutant. Thus, we propose a new role for FlaB in the defense of campylobacters against bacteriophage infection.