[Immunohistochemical determination of Chlamydia psittaci/pecorum and C.trachomatis in the piglet gut]

The jejunum, ileum, caecum and colon of 200 piglets were investigated immunohistochemically for the presence of Chlamydia psittaci and C. trachomatis using a vitelline IgY. Positive samples were later labelled using a commercial C. trachomatis polyclonal antiserum. Chlamydia were present in 33 (16.4%) of the animals, and 30 out of 33 were labelled by C. trachomatis polyclonal antiserum. Inclusions occurred predominantly (67%) in the large intestine. The serological results (CFT, ELISA) did not correlate well with immunohistochemical labelling in the gut. The incidence of Chlamydia rose from 6.9% in animals up to 4 weeks, to 41.8% in those over 4 weeks of age. A correlation between chlamydia and enteric disease was not obvious. Besides chlamydia, most of the diseased animals harboured other additional agents. In conclusion, intestinal chlamydiae in piglets, predominantly C. trachomatis, exist in Switzerland, although their pathogenic potential seems to be low.