No abstract

Bovine tuberculosis (BTB) is a zoonosis caused by the bacterium Mycobacterium bovis, which induces the development of nodular and granulomatous lesions in various animal tissues. The recognition of these suggestive gross lesions during postmortem sanitary inspection in slaughterhouses provides a presumptive diagnosis, which requires the use of complementary tests to confirm the disease. This study aimed to verify the occurrence of BTB in cattle slaughtered in slaughterhouses in the state of Ceará, Brazil, using bacteriological and molecular methods. To this end, suggestive lesions were analyzed on carcasses condemned by the “Serviço de Inspeção Estadual” (SIE). The samples were submitted to microbiological analysis using culture media and specific staining followed by spoligotyping molecular technique for identification and genotyping of the mycobacteria. Occurrence of lesions suggestive of BTB was verified in bovine carcasses (0.071%) from different municipalities of the state. These lesions were located mainly in the lung (95.12%), lymph nodes (58.53%), and liver (36.58%). Microbiological culture showed bacterial isolation (17.94%), with the growth of colonies showing morphological and tannic characteristics belonging to genus Mycobacterium spp. Genetic polymorphism analysis identified M. bovis in all isolates, which were discriminated into six spoligotypes (SB0121, SB0295, SB1064, SB0120, SB0870, and SB0852). These profiles have been described in Brazil and several areas of the world, except for profiles SB1064 and SB0852, which were described in the country for the first time. The results show that the association of the diagnostic methods used was the basis for the first study on identification of mycobacteria found in the state, which may provide a database for the epidemiological study of BTB in the state of Ceará.

Mycobacterium bovis is responsible for bovine and buffalo tuberculosis, an important zoonotic disease with global distribution. The knowledge of the distribution and the precise identification of this disease, including advanced diagnoses such as spoligotyping, allows choosing the best strategies to fight the disease’s progress. The present work aimed to investigate mycobacteria’s presence, genotype their strains, and evaluate tuberculosis cases’ spatial distribution from suggestive lesions in carcasses of bovine and buffalo inspected in slaughterhouses under an official inspection regime in the state of Bahia, Brazil. The study investigated 453,417 animals. Among these, 31 (0.007%) from 17 municipalities were suspected of tuberculosis. Among the culture medium growth, 95% of these were categorized as alcohol-acid resistant bacilli (BAAR). All isolates were subjected to spoligotyping and 95% were confirmed as M. bovis (SB0120, SB0121, SB0852, SB0828, SB0295, SB0881, SB1648, SB6119, SB0140, SB1055). The strain SB0120 was the most prevalent, and this profile has been described in cases of human tuberculosis by M. bovis, highlighting the zoonotic potential of this profile. This study also identified strains never reported in Bahia, highlighting a distinctive pattern from other parts of Brazil, besides mixed infections. Besides, to identify strains never before described in the state, highlighting a distinctive pattern in Brazil (SB6119 and SB0852, respectively). An unpublished profile was identified and inserted in the international database (Mbovis.org), named SB2715.

The objective of this research was to identify Mycobacterium bovis in lesions suggestive of tuberculosis in bovine carcasses in the State of Ceará, by means of bacteriological and molecular diagnostic tests. Between August 2017 and January 2019, the State inspection service (SIE) inspected 59,512 cattle, of which 7.4% (44 / 59,512) presented suggestive lesions. Of these animals, 68 samples were sent, of which 4.5% (31/68) located in the lung, 2.9% (20/68) in lymph nodes, 2.0% (14/68) in the liver, and 0.4% in the carcass (3/68). When performing bacteriological isolation, 15.9% (7/44) of bovines showed colony growth in the samples. The smears of the isolates were submitted to Zielh-Neelsen staining and all confirmed acid-fast bacilli. The polymerase chain reaction identified all isolates 100% (7/7) as M. bovis. The association of diagnostic techniques allowed to identify the presence of the agent in the State and the molecular analysis proved to be a beneficial technique in the monitoring of bovine tuberculosis and can be used as an auxiliary method in the bovine tuberculosis control and eradication program in the State of Ceará.