Diagnosis of placental pathogens in small ruminants by immunohistochemistry and PCR on paraffin-embedded samples

A histological study was carried out on 58 formalinfixed and paraffin-embedded samples of placenta from sheep and goats that had aborted, and the placental lesions were graded. Sequential histological sections of each cotyledon were then immunostained with specific antibodies and used for PCR detection of Chlamydophila abortus, Coxiella burnetii, Salmonella Abortusovis, Brucella melitensis, Listeria monocytogenes and Toxoplasma gondii. Most of the cotyledons showed different degrees of placentitis. The proportional agreement between the two techniques was 0·879 (κvalue 0·746). C abortus was the most prevalent pathogen. Mixed infections were common.