THE ASSOCIATION OF CAMPYLOBACTER HYOINTESTINALIS AND CAMPYLOBACTER SPUTORUM SUBSPECIES MUCOSALIS WITH PROLIFERATIVE ENTERITIS OF SWINE. (VOLUMES I AND II) (SEROLOGY, PATHOLOGY, IMMUNOHISTOLOGY, ANIMAL MODEL)

The definitive cause of proliferative enteritis (PE) of swine is not clear. Pathologic observation reveals that the disease is associated with an intracellular Campylobacter sp in the intestinal epithelium. Five studies were conducted to investigate whether C hyointestinalis, a recently identified species, and C sputorum subsp mucosalis are associated with the pathogenesis of this disease.;The immunofluorescent study (Study 2) demonstrated that both C hyointestinalis and subsp mucosalis are frequently present in the PE intestines but the former is the predominent intracellular organism in the proliferative epithelium. The results of an immunoperoxidase study (Study 3) confirm the preceeding findings which suggest that C hyointestinalis may be the primary agent of PE.;Oral challenge (Study 4) of pigs with pure cultures of C hyointestinalis and subsp mucosalis (alone or together) did not induce PE. The inability to reproduce the disease may be because of loss of the virulence incultured Campylobacter strains; otherwise, other unknown factors may be involved. The final study (Study 5) demonstrated that swine PE may be experimentally transmitted to mice via feeding gut homogenates of PE pigs. Challenge exposure of mice to pure cultures of various Campylobacter sp, did not reproduce the disease. One particular C hyointestinalis strain, however, could cause sudden death or severe illness with acute intestinal epithelial necrosis and bacteremia in 20% of infected mice by 1-5 days postinoculation.;These 5-part studies did not completely prove that C hyointestinalis or C sputorum subsp mucosalis is the only causative agent of PE. The results, however, suggest that C hyointestinalis is an invasive organism and may be an important intestinal pathogen.;Serologic study (Study 1), using a microagglutination test, revealed that C hyointestinalis and subsp mucosalis are antigenically 2 distinct species. Antibody titers to both species were rarely detected in PE pigs and weanling pigs but were frequently detected in normal pigs of other ages. These results indicate that exposure to either organism (so that antibody is produced) has no correlation with clinical occurrence of PE in such pigs or herds.