Reproduction of proliferative enteritis in gnotobiotic pigs.

Gnotobiotic pigs dosed orally with filtrates (0.8 and 0.65 micron) of intestinal mucosa from a pig affected by proliferative haemorrhagic enteropathy developed lesions of proliferative enteritis, affecting mainly the ilea. Other piglets dosed with filtrates of affected mucosa from the same source and from other proliferative haemorrhagic enteropathy or intestinal adenomatosis mucosae, did not develop lesions. All inocula contained numerous campylobacter-like organisms evident in stained smears, Campylobacter coli and C mucosalis. C coli colonised the intestines of all the pigs, C hyointestinalis (which was not detected in the inocula) did so in some affected and unaffected pigs while C mucosalis was not recovered from any of the intestines. Although other explanations are possible the number and viability of the intracellular campylobacter-like forms is likely to be the critical factor in infectivity. In affected intestines the crypts were colonised by campylobacter-like organisms, and their attachment and entry into enterocytes was associated with cellular proliferation. Immunofluorescence reactions suggested that the intracellular campylobacter-like organisms were antigenically distinct from the known Campylobacter species. It is possible, therefore, that porcine proliferative enteritis is caused by a further unidentified Campylobacter species, or that there is a marked antigenic change of C hyointestinalis or C coli on entry into porcine enterocytes.