Histopathological and PCR Mycobacterium bovis Identification in Mexican Opossums (Didelphis virginiana) from Hidalgo, Mexico

Abstract

Mycobacterium bovis is the causal agent of bovine tuberculosis, this bacillus affects domestic wild animals as well as human beings, thus considered a zoonosis. Didelphis virginiana is the Mexican marsupial in spite of being a wild animal, it has been adapted to live near to human and it can be included in the people's diet. The opossum could be susceptible to be infected by M. bovis. There were captured six adult animals in the Mexican state of Hidalgo; the animals were sacrificed using an overdose of sodic pentobarbital; samples were taken from lung, spleen, intestinal tract, liver, mediastinic, retrofaringeal, submaxilar lymph nodes; Necropsy findings and histophatological lesions are suggestive of chronic disease as it occurs in tuberculosis cases. Histopatological study showed calcification perfectly surrounded by dense irregular collagen tissue in which a detachment of capsule is found. Two of the specimens in the study showed positive in tuberculosis, using nested PCR. The present study shows the risk that could exist during the transmission of tuberculosis maybe due to Didelphis virginiana coexistence with infected bovine cattle and human.