Immunohistochemical and Molecular Approaches for the Diagnosis of Campylobacter fetus subsp. venerealis in Natural Cases of Bovine Abortion

Rapid and precise diagnosis in natural field cases of bovine abortion caused by Campylobacter fetus subsp. venerealis warrants use of most sensitive and reliable diagnostic methods. In the present study, an array of gross, histopathological, immunohistochemical and real time polymerase chain reaction (PCR) technique(s) for amplification of the gene encoding ISCfe1 insertion site were applied for the diagnosis of C. fetus subsp. venerealis in cases of abortion. Abortion occurred between 4 and 6 months of gestation with an average gestational age of 5 months. Histopathologically, fetal lesions recorded were bronchopneumonia and interstitial pneumonia. C. fetus with the typical morphology of spirals was observed in sections of lung with IHC staining positive reaction. In placenta, there was dense staining of clusters of the organisms which were evident as dark brown bodies showing positive reaction with IHC. Four samples (two from stomach contents, one from pooled fetal tissue and one from vaginal discharges) out of 84 tested cases were positive by real-time PCR for diagnosis of C. fetus subsp. venerealis in cases of abortion. Real time PCR techniques using ISCfe1 insertion site is most sensitive technique for diagnosis of C. fetus subsp. venerealis associated abortion. © 2014, The National Academy of Sciences, India.