Porcine proliferative enteritis: serological, microbiological and pathological studies from three field epizootics

Three outbreaks of porcine proliferative enteritis were evaluated clinically, pathologically, microbiologically and serologically. The disease was characterized by a chronic intermittent diarrhea. Pathological lesions included a thickened, turbid ileum with the microscopic appearance of proliferating ileal crypt epithelial cells. Comma shaped intracytoplasmic organisms were observed in the apical portions of the proliferating crypt epithelial cells with a Warthin-Starry silver stain. Microbiologically, both Campylobacter sputorum subspecies mucosalis and Campylobacter hyointestinalis, were cultured from ileal specimens of seven pigs with lesions of porcine proliferative enteritis. Microagglutination antibody titers were determined on sera from 12 of 14 pigs with porcine proliferative enteritis and on sera from 91 clinically normal swine. Pigs with porcine proliferative enteritis had a low antibody titer to subspecies mucosalis that ranged from 1-3 with a mean of 2.17. A varied C. hyointestinalis titer from 3-7 with mean of 4.83 was determined. Titers to either subspecies mucosalis and C. hyointestinalis were higher in non-porcine proliferative enteritis pigs. The results indicate that the presence of a positive titer to either C. hyointestinalis or subspecies mucosalis in swine is not indicative of clinical disease. The isolation of C. hyointestinalis from diseased ileal specimens (porcine proliferative enteritis) confirms previous reports implicating this agent in the disease.