Immunohistochemical detection of Brucella melitensis antigens in lungs tissues of sheep and goats diagnosed with different diseases at necropsy

Brucellosis is one of the world most common zoonotic diseases and infected animals are often the source of human infection. The prevalence of Brucellosis in cases presented to the necropsy unit of the Faculty of Veterinary Medicine, Universiti Putra Malaysia from 2007 to 2012 was unknown. In a retrospective study, the presence of B. melitensis antigen in 107 formalin-fixed, paraffin embedded lung tissue blocks of small ruminants were investigated using immunohistochemistry (IHC) technique. Sample blocks from year 2007 to 2012 were collected from postmortem archive in necropsy unit of the Faculty of Veterinary Medicine, Universiti Putra Malaysia. A total of 10 tissue samples with positive immunoreactivity to B. melitensis antigen were detected. Out of the 10 positive tissue samples, one was from sheep and the rest were from goats. The prevalence of B. melitensis in post-mortem cases for the six year period was 9.4%. Statistical analysis revealed there were no difference between breed, gender and age among the 10 positive samples. Based on the findings of this study, it was concluded that Brucella antigen could be present in small ruminant species which had died of other diseases and this could pose significant public health risk, especially among staff and students while conducting post-mortem examinations. Strict protective measures should be emphasized before carrying out postmortem examinationKeywords: Brucella melitensis, Immunohistochemistry, Post mortem, Small ruminan