Caracterização histopatológica, imunohistoquímica e determinação molecular de Mycobacterium bovis de lesões sugestivas de tuberculose em bubalinos abatidos para consumo no estado do Amapá

Abstract

The creation of buffalo is an important source of income in Amapá, an important sector in the local economy. Tuberculosis is an infectious disease of worldwide distribution, which occurs in cattle and buffaloes caused mainly by Mycobacterium bovis. The disease has debilitating chronic nature with economic impact on the production of meat and milk in different regions of the world, besides being an important zoonosis. Aiming to characterize M. bovis in suggestive of tuberculosis lesions detected in buffalo inspection in the State of Amapá, through histopathological and immunohistochemical methods (IHC) and molecular analysis, there was the collection of 109 samples suggestive of tuberculosis lesions. For histopathological analysis, we used standard techniques for paraffin by hematoxylin and eosin and Fite-Faraco. For IHC was used the method of peroxidase-antiperoxidase (PAP) with a polyclonal rabbit antiserum against M. bovis (Dako B0124). For molecular analysis, mycobacterial DNA extraction was directly performed lymph node and treated by the phenolchloroform method through two amplification protocols (conventional PCR and Nested- PCR). Histologically, 94.5% (103/109) had typical granulomatous tissue reaction tuberculoide injury (LT), while in 5.5% (06/109) without features of tuberculoid granulomas (p <0.0001). The results obtained by IHC among the positive cases by histopathology, all had some kind of injury classified in several stages by histopathology, and observed that most of them 82.2% (74/90; p <0.0001) was only stage IV. Among the negative cases, necrotic lesions presenting only the last stage of development (IV) were also frequently 52.5% (10/19) and 31.5% (06/19) were also negative in the histopathologic ( p = 0.0030). Of the 103 positive samples for histopathology, 73.8% (76/103) were PCR positive reaction to the genus Mycobacterium and 64.1% (66/103) had amplification for the RD4 region, confirming the deletion, exclusive of the species M. bovis. The results showed that tuberculosis is present in buffalo herds of Amapá and regions of Marajó in Pará, representing a serious risk to public health.