Little information is available on reproduction of proliferative enteropathy (PE) using a virulent pure culture of Lawsonia intracellularis. Reproduction of the disease using PE-diseased mucosa homogenates, however, is well-characterized. The aims of this study were to evaluate and compare clinical signs, growth performance and the severity of lesions in pigs inoculated with intestinal mucosa homogenate or pure culture of the homologous L. intracellularis isolate. Five-week-old pigs were inoculated with pure culture of L. intracellularis (isolate PHE/MN1-00; n=10), PE-diseased mucosa (n=10), or control media (n=4). The L. intracellularis isolate PHE/MN1-00 used in the pure culture inoculum was extracted from a fragment of the same intestine used to prepare the mucosa homogenate. Clinical signs and growth performance were evaluated throughout the study. Fecal shedding was evaluated in all animals weekly during the experiment. All animals were euthanized 22 days post-inoculation, the intestines were examined grossly and histologically. Results showed that both the infection procedures reproduced clinical disease, macroscopic and histologic lesions typical of PE. Fecal shedding was detected in animals in both challenge groups. In conclusion, the L. intracellularis isolate PHE/MN1-00 reproduces typical clinical signs and lesions of PE similar to the homologous infection with an intestinal mucosa homogenate.
Bibliographical noteFunding Information:
R.M.C. Guedes was supported by the Brazilian government sponsoring agency “Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico” (CNPq), and Universidade Federal de Minas Gerais. Partial funding for the research was provided by grant 00-52100-9687 from the USDA-CSREES-IFAFS research initiative. We thank Dr. Rodney Frank, Debra Swanson and Dr. Maria Isabel M. Coelho Guedes for technical assistance.
- Intestinal mucosa homogenate
- Lawsonia intracellularis
- Proliferative enteropathy
- Pure culture