Bovine tuberculosis due to Mycobacterium bovis and other mycobacteria among water buffalo (Bubalus bubalis) from the Brazilian Amazon

Abstract

Introduction: Zoonotic tuberculosis is a disease of public health importance worldwide, especially in developing countries. The present study aimed to investigate the role played by Mycobacterium bovis and other mycobacteria as etiologic agents of bubaline tuberculosis (TB) in the Brazilian Amazon region. Methodology: Granulomatous lesions suggestive of TB obtained from 109 buffaloes (n =109) during sanitary inspection at slaughter were subjected to histopathological evaluation, immunohistochemical (IHC) detection of Mycobacterium antigens, and to molecular tests (PCR) to detect hsp65, IS6110 and RD4 genes, which are specific to Mycobacterium spp., Mycobacterium tuberculosis Complex (MTBC) and M. bovis, respectively. Results: PCR results indicated Mycobacterium infection in 87.2% of the cases, of which 69.5% were positive for M. bovis, 27.4% belonged to MTBC, and 3.1% were probably non-TB mycobacteria. There was good agreement between the genus-specific molecular technique and the histopathological analysis. This high frequency of TB cases caused by non-M. bovis suggests a diversified scenario of mycobacteria associated with bubaline TB in the Brazilian Amazon region. Conclusions: The results reinforce the need of discussing the inclusion of more accurate techniques in examinations carried out by Inspection Services in Brazil.