Poultry Probiotic To Battle Foodborne Pathogen

NORWICH, United KingdomThe coat of potential poultry probiotic Lactobacillus johnsonii has been recently characterized, giving the first clues of how it may be used to exclude pathogenic bacteria from chickens, according to a new study published in the Journal of Biological Chemistry.

Researchers at the Institute of Food Research (IFR) characterized the coat of the poultry probiotic Lactobacillus johnsonii, to develop a better idea of its role and how it may help in combatting foodborne pathogen Clostridium perfringens. The probiotic has previously been shown to exclude C. perfringens from the guts of poultry, opening the door to it being developed as a way of reducing necrotic enteritis in poultry and food poisoning in humans.

Using NMR spectroscopy, the researchers discovered the coat is made up of two types of exopolysaccharides (EPS), which are long sugar-containing molecules that many bacteria use to encapsulate themselves. This capsule may help the bacteria to cope with environmental stress, or aid colonization and adhesion.

"Characterizing the EPS structures in the L. johnsonii strain is the first step to explaining how it might outcompete C. perfringens," said Arjan Narbad, Ph.D., Gut Health and Food Safety Program, IFR.

Previous studies had identified potential genes in L. johnsonii for producing EPS, giving the researchers tools to probe how the bacteria synthesize these molecules. Knocking out the whole cluster of EPS genes meant the bacteria produced no capsule. Further analysis of the genes by IFR Ph.D. student Enes Dertli uncovered their potential roles in the capsule biosynthesis process. However, more research is needed to fully understand the system and how it is regulated.

This strain of Lactobacillus johnsonii is now being taken through farm-scale trials to assess its potential use to combat pathogenic infections of poultry by bacteria such as C. perfringens.

Prior research conducted in 2012 determined the probiotic may be capable of minimizing the risk of Listeria infection when combined with the Listeria protein. The probiotic helps block the same paths the bacteria uses to pass through intestinal cells and into bloodstreams.