A new method for the experimental production of necrotic enteritis and its use for studies on the relationships between necrotic enteritis, coccidiosis and anticoccidial vaccination of chickens

Abstract

A new method for the experimental production of necrotic enteritis in chickens is described. The main features are the use of a diet high in wheat and fish meal content; oral administration of a non-lethal inoculum of the coccidium Eimeria maxima followed 6 days later by the bacterium Clostridium perfringens type A per cloaca, so that the bacterial inoculum is deposited at the time and place when and where the intestinal coccidial lesions are maximal; grading of coccidial and clostridial lesions in individual birds sampled during the 14 days following the coccidial infection. The new method was used to examine the relationship between clostridial and coccidial infections. Frank coccidiosis, caused by virulent E. maxima, exacerbated the lesions of necrotic enteritis and other clinical effects due to a subsequent challenge with virulent C. perfringens type A. Immunization with a live, pentavalent, attenuated anticoccidial vaccine (Paracox-5) protected against a severe challenge with heterologous E. maxima. Furthermore, vaccination with Paracox-5, by virtue of its protection against clinical coccidiosis due to the E. maxima challenge, indirectly protected birds against a subsequent challenge with virulent C. perfringens. The results are reconciled with previous field observations on concomitant coccidiosis and necrotic enteritis in chicken flocks.

The successful experimental induction of necrotic enteritis in chickens by Clostridium perfringens: a critical review

“…have often been used in conjunction with C. perfringens to induce NE experimentally. Since NE is a disease of small intestine, E. acervulina , E. maxima or E. necatrix are the most suitable species [2,15,23,40,71]. There are differences in opinion as to whether the more virulent Eimeria , such as E. necatrix are better than the less virulent E. acervulina choices for this purpose [2,72].…”

“…The time of administration of the coccidial vaccine or of virulent Eimeria is critical, and should be not more than 4–5 days before the C. perfringens challenge so that the coccidia-induced intestinal damage coincides with bacterial challenge [21,40]. When the C. perfringens challenge lasted for 4 days, no significant difference was observed in the severity of lesions in birds receiving coccidial vaccine 3 days before or one day after the onset of C. perfringens challenge [20,41].…”

Animal models to study the pathogenesis of human and animal Clostridium perfringens infections

“…The assumption is that Eimeria spp. exerts its effect on the disease model by causing damage to the gut epithelium and thus provides an entry point in which C. perfringens can colonize and proliferate (Williams et al 2003; Van Immerseel et al, 2008), although induction of host mucogenesis may also be important (Collier et al, 2008). Eimeria spp.…”

Prevalence and distribution ofEimeriaspecies in broiler chicken farms of different capacities

“…These species of Eimeria have different pathogenicity; E. tenella and E. necatrix are the most pathogenic and cause bloody lesions, high morbidity and mortality in naive chickens [19, 32]; E. acervulina , E. maxima and E. brunetti also cause clinical diseases; E. praecox and E. mitis , although considered to be relatively non-pathogenic [32], do cause a reduced feed conversion efficiency and growth rate [56]. Also, infection with certain species of Eimeria was demonstrated to be implicated in predisposing birds to necrotic enteritis [55], through lesions that compromise gut integrity, and allow the proliferation of pathogens [52]. …”