A Poultry Subclinical Necrotic Enteritis Disease Model Based on Natural Clostridium perfringens Uptake

Necrotic enteritis (NE) in poultry is an opportunistic infection caused by Clostridium perfringens. Well-known as a multifactorial disease, NE development is under the influence of a wide range of environmental risk factors that promote the proliferation of pathogenic C. perfringens at the expense of nonpathogenic strains. Current in vivo NE challenge models typically incorporate pre-exposure to disease risk factors, in combination with exogenous C. perfringens inoculation. Our goal was to enhance current models using a natural uptake of C. perfringens from the barn environment to produce a subclinical infection. We incorporated access to litter, coccidial exposure (either 10x or 15x of the manufacturer-recommended Coccivac B52 Eimeria vaccine challenge; provided unspecified doses of E. acervulina, E. mivati, E. tenella, and two strains of E. maxima), feed composition, and feed withdrawal stress, and achieved the commonly observed NE infection peak at 3 weeks post-hatch. NE severity was evaluated based on gut lesion pathology, clinical signs, and mortality rate. Under cage-reared conditions, 15x coccidial vaccine-challenged birds showed overall NE lesion prevalence that was 8-fold higher than 10x coccidial vaccine-challenged birds. NE-associated mortality was observed only in a floor-reared flock after a 15x coccidial vaccine challenge.

Automated summary

Necrotic enteritis (NE) is an opportunistic infection in poultry caused by Clostridium perfringens. It is influenced by various environmental risk factors, and current research aims to enhance models by inducing subclinical infection through exposure to the barn environment.