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.

Isolation, host specificity and genetic characterization of Campylobacter specific bacteriophages from poultry and swine sources.

The isolation and characterization of 304 Campylobacter specific bacteriophage isolates from broiler and swine sources is reported in this study. Genome size characterization determined by PFGE classified these isolates,called CAM1-CAM304, within the campylophages group II (n = 18) and group III (n = 286). Host range analyses showed a high host specificity and similar lytic spectrum among isolates of the same group. Campylophages of group II infected C. jejuni, C. coli and even a C. fetus strain whereas those of group III only infected C. jejuni strains. The most promising 59 campylophage candidates were selected according to their lytic activity and their genetic diversity was analyzed by RFLP using SmiI and HhaI endonucleases for group II and III campylophages, respectively. Moreover, RAPD-PCR technique was for the first time assessed in the genetic characterization of campylophages and it was shown to be effective only for those of group II. Bacteriophage isolates grouped in a same genotype displayed different host ranges, therefore, 13 campylophages of group II and eight of group III were differentiated considering all the approaches assayed. An in-depth analysis of these bacteriophages will be performed to confirm their promising potential for the biocontrol of Campylobacter within the farm to fork process.

Efficient isolation of Campylobacter bacteriophages from chicken skin, analysis of several isolation protocols.

The application of Campylobacter specific bacteriophages appears as a promising food safety tool for the biocontrol of this pathogen in the poultry meat production chain. However, their isolation is a complicated challenge since their occurrence appears to be low. This work assessed the efficiency of seven protocols for recovering Campylobacter phages from chicken skin samples inoculated at phage loads from 5.0 × 101 to 5.0 × 106 PFU/g. The enrichment of chicken skin in selective Bolton broth containing target isolates was the most efficient procedure, showing a low detection limit of 5.0 × 101 PFU/g and high recovery rates of up to 560%. This method's effectiveness increased as phage concentration decreased, showing its suitability for phage isolation. When this method was applied to isolate new Campylobacter phages from retail chicken skin, a total of 280 phages were recovered achieving an isolation success rate of 257%. From the 109 samples 68 resulted phage positive (62%). Chicken skin could be, therefore, considered a rich source in Campylobacter phages. This method is a simple, reproducible and efficient approach for the successful isolation of both group II and III Campylobacter specific bacteriophages, which could be helpful for the enhancement of food safety by reducing this pathogen contamination in broiler meat.