Improving control of Campylobacter jejuni in poultry production

Author Sophie Chagneau, Supervisor Alexandre Thibodeau

Chaire de Recherche en Salubrité des Viandes (CRSV) [Research Chair in Meat Safety] of the Université de Montréal and the Centre de recherche en infectiologie porcine et avicole (CRIPA) [Swine and Poultry Infectious Diseases Research Center] funded by the Fonds de Recherche du Québec – Nature et technologies (FRQNT), Université de Montréal

Article published in the magazine NOUVAiles on September 2023

After years of research, the Research Chair in Meat Safety of the Université de Montréal and CRIPA-FRQNT have discovered a second application for a food additive that reduces the carriage rate of the pathogen Campylobacter jejuni in poultry.

Campylobacter jejuni (C. jejuni) represents a major public health problem, causing numerous foodborne infections from the consumption of undercooked chicken meat or liver. In rare cases, the infection can lead to Guillain-Barré syndrome, characterized by weakness in the limbs and potentially life-threatening breathing difficulty. For decades, many researchers have tried to control C. jejuni by vaccinating chickens or by giving them probiotics. But to date, no effective treatment has been found, and it is still unclear how chickens become colonized by these bacteria. We need to deepen our knowledge in order to find an appropriate control measure for poultry farming.

CRSV, in collaboration with the CRIPA-FRQNT of the Université de Montréal, therefore first carried out a detailed characterization of the genetic variants (strains) of C. jejuni, isolated from chicken intestines. These key data led to the development of experimental models involving the oral administration of different strains of C. jejuni to chickens raised at the experimental facilities of the Faculty of Veterinary Medicine. These models were refined over time to reflect the reality in the field. As reported in the scientific literature, CRSV was able to replicate multi-infections with several strains of C. jejuni in chickens, leading to the colonization of the intestine by these strains, with certain ones predominating. In addition, we reproduced the internal contamination of the liver by C. jejuni over the life of the birds.

After numerous experiments, we came to realize the key role of amino acids, components part of the proteins, in the ability of C. jejuni strains to colonize the intestine and contaminate chicken livers. Thanks to these significant scientific advances, we have been able to reduce the intestinal bacterial load of C. jejuni and prevent its spread to the liver by adding an enzyme called protease to chicken feed, which increases the digestibility and absorption of protein in the animal's intestine. This leads to an increased use of certain amino acids by the birds, which reduces their availability for C. jejuni.

In order to improve the treatment, additional experiments are needed to elucidate the underlying mechanisms, such as studying the microbial communities that inhabit the intestinal microbiota and detailed analysis of the amino acids available in the intestine.

Picture illustrating oral administration of Campylobacter jejuni to a 14-day-old chicken in an experimental facility at the Faculty of Veterinary Medicine.

(Source: picture taken by the Research Chair in Meat Safety)