Avaliação bacteriológica e molecular por Spoligotyping da tuberculose a partir de bovinos e bubalinos abatidos em abatedouros oficiais e em vísceras comercializados nas feiras livres no estado da Bahia - Brasil

Abstract

Mycobacterium bovis is the main responsible for bovine and buffalo tuberculosis, an important zoonotic disease with global distribution. The precise investigation of this disease, including more advanced diagnoses, like Spoligotyping, allows to choose the best strategies to combat the disease progression. As in other states, understanding the frequency and distribution pattern of the disease in Bahia contributes to effective planning of control actions, as well as monitoring the progress of the national TB control and eradication program and, in this context, slaughterhouses play a key role. The objective was to investigate the occurrence of lesions suggestive of tuberculosis in bovine and buffalo carcasses inspected in slaughterhouses under an official inspection regime, as well as to identify the presence of mycobacteria in the same and in viscera samples marketed in open fairs in the state of Bahia. Of the 29 free-trade samples, 20 could be analyzed, excluding autolysed and contaminated, and growth was shown in 25% (5/20) of them, but no evidence of BAAR was shown, however, the environment of the fairs was revealed with inappropriate sanitary conditions. A total of 453,417 carcasses were investigated under the state and federal inspection service, of which 31 animals (0.007%) were considered suspect, from which 49 lesions suggestive of TB were collected from animals from 17 municipalities. Of these, 27 cattle could be analyzed resulting in 74.1% (20/27) growth in selective culture medium and 95% (19/20) were BAAR. DNA from the colonies was extracted by thermolysis. All isolates were submitted to Spoligotyping with 95% confirmed profiles of M. bovis (SB0120, SB0121, SB0852, SB0828, SB0295, SB0881, SB1648, SB0140, SB0140, SB1055) showing the genotype strain SB0120 xi to be the most prevalent and related with cases of human tuberculosis indicating the zoonotic potential of this profile. Spoligotyping allowed to confirm the presence of mixed infections, a high diversity of isolate strains patterns in Bahia and also allowed comparison with other states and countries, showing isolated strains in Brazil, one of the isolated isolates in the literature. The analysis of the spatial distribution has proved to be an important tool for directing health protection actions, allowing for more specific recommendations of the national program for the control and eradication of bovine tuberculosis in the state of Bahia, Brazil.