Utilization of monoclonal antibodies to evaluate the involvement of Campylobacter jejuni in proliferative ileitis in Syrian hamsters (Mesocricetis auratus).

The role of Campylobacter jejuni in the pathogenesis of proliferative ileitis in Syrian hamsters was evaluated with monoclonal antibodies of different specificities. Monoclonal antibodies were produced with two different specificities: one for all members of the genus Campylobacter tested (antibody 8322-2E6) and one for C. jejuni and Campylobacter coli (antibodies 841-2A11, 841-4C6, and 841-5B1). Heal sections from healthy hamsters, from hamsters with naturally occurring proliferative ileitis, and from hamsters with experimentally induced proliferative ileitis were examined by using fluorescein isothiocyanate-labeled, Campylobacter sp.-specific 8322-2E6 and tetramethylrhodamine isothiocyanate-labeled C. jejuni-C. coli-specific 841-2A11 for direct dual-labeling immunofluorescence. Organisms which stained with the C. jejuni-C. coli-specific monoclonal antibody were observed in the ileal lumens and along the distal tips of the villi of hamsters with either experimentally induced or naturally occurring proliferative ileitis. In contrast, organisms identified by the Campylobacter sp.-specific monoclonal antibody were present deep within the villus lumens and crypts and intracellularly within the apical portions of the epithelial cells. No organisms stained with the C. jejuni-C. coli-specific monoclonal antibody were observed in ileal sections from control hamsters; an occasional intracellular organism stained with the Campylobacter sp.-specific monoclonal antibody was observed in 2 of 10 control hamsters. Thus, at least two immunologically distinct patterns were identified in ileal sections from hamsters with proliferative ileitis. On the basis of these results, we conclude that the organism seen intracellularly in ileal sections from hamsters with proliferative ileitis is a member of the genus Campylobacter but that it probably is not C. jejuni or C. coli.