PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Rodrigues R.A., Meneses I.I.F.S., Jorge K.S.G., Silva M.R., Santos L.R., Lilenbaum W., Etges R.N. & Araújo F.R. 2017. False-negative reactions to the comparative intradermal tuberculin test for bovine tuberculosis. Pesquisa Veterinária Brasileira 37(12):1380-1384. Embrapa Gado de Corte, Av. Rádio Maia 830, Campo Grande, MS 79106-550, Brazil. E-mail: flabio.araujo@embrapa.br According to the Brazilian National Program for the Control and Eradication of Animal Brucellosis and Tuberculosis (PNCEBT), the routine tests for the diagnosis of bovine tuberculosis in the country are the simple intradermal tuberculin test (SITT) of the Ministry of Agriculture, Livestock and Food Supply (MAPA), the caudal fold test and the comparative intradermal tuberculin test (CITT). The latter is also used as a confirmatory test. A group of 53 animals from three dairy herds in a focal area for bovine tuberculosis, that were submitted to depopulation in the state of Rio Grande do Sul, were submitted to the CITT. Tissues were cultured and the resulting colonies were confirmed by PCR and DNA sequencing. Among the 53 animals analyzed using the CITT, 32 (60.4%) were negative, 14 (26.4%) were positive and seven (13.2%) results were inconclusive. The CITT detected 11 of the 39 animals with culture-confirmed M. bovis infection as positive. Among the total of 14 uninfected animals based on cultures, the CBT detected eight as negative. Thus, the CITT demonstrated sensitivity of 28.2% and specificity of 57.1% for the population sampled. A total of 24/32 (75.0%) of the animals with negative CITT results were culture positive (confirmed by PCR) and were considered false negatives based on the CITT. The maintenance of these false-negative animals in herds has serious implications for the control of the disease, since they can be a source of infection. The addition of complementary tests could help identify such animals and increase the odds of diagnostic success.

• Tuberculosis Mycobacterium bovis Tuberculin Test tuberculose tuberculose

Abstract in Portuguese:

RESUMO.- Rodrigues R.A., Meneses I.I.F.S., Jorge K.S.G., Silva M.R., Santos L.R., Lilenbaum W., Etges R.N. & Araújo F.R. 2017. False-negative reactions to the comparative intradermal tuberculin test for bovine tuberculosis. [Reações falso-negativas ao teste cervical comparativo para tuberculose bovina.] Pesquisa Veterinária Brasileira 37(12):1380-1384. Embrapa Gado de Corte, Av. Rádio Maia 830, Campo Grande, MS 79106-550, Brazil. E-mail: flabio.araujo@embrapa.br No Brasil, segundo o Programa Nacional de Controle e Erradicação da Brucelose e Tuberculose Animal (PNCEBT), do Ministério da Agricultura, Pecuária e Abastecimento (MAPA), os testes de rotina para o diagnóstico de tuberculose bovina são o teste cervical simples (TCC), o teste da prega caudal (TPC) e o teste cervical comparativo (TCC), sendo que o último também é utilizado como teste confirmatório. Um grupo de 53 animais oriundos de três rebanhos leiteiros de área de foco para tuberculose bovina que foram submetidos a vazio sanitário no Rio Grande do Sul foi submetido ao TCC. Os tecidos destes animais foram cultivados e as colônias resultantes confirmadas por PCR e sequenciamento de DNA. Dos 53 animais analisados no TCC, 32 (60,4%) foram negativos, 14 (26,4%) positivos e sete (13,2%) inconclusivos, com base no PNCEBT. O TCC detectou como positivos 11 dos 39 animais com infecção por M. bovis confirmada por cultivo. Do total de 14 animais não infectados, baseado na cultura, o TCC detectou oito como negativos. Assim, o TCC apresentou, para a população amostrada, sensibilidade de 28,2% e especificidade de 57,1%. Um total de 24/32 (75,0%) dos animais negativos ao TCC foi positivo no cultivo (confirmado por PCR), sendo considerados falso-negativos ao TCC. A manutenção destes animais falso-negativos nos rebanhos tem sérias implicações para o controle da enfermidade, já que os mesmos podem ser fonte de infecção. A adição de testes complementares poderia auxiliar na identificação destes animais, aumentando a cobertura diagnóstica.

Abstract in English:

ABSTRACT.- Cazola D.O., Jorge K.S.G., Zumárraga M.J., Souza-Filho A.F., Araújo F.R. & Osório A.L.A.R. 2015. [Identification and genotyping of Mycobacterium bovis from positive cattle in skin test for tuberculosis in the State of Mato Grosso do Sul, Brazil.] Identificação e genotipagem de Mycobacterium bovis em bovinos positivos no teste intradérmico para tuberculose em Mato Grosso do Sul. Pesquisa Veterinária Brasileira 35(2):141-147. Laboratório de Micobacteriologia e Biologia Molecular, Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Müller 2443, Campo Grande, MS 79074-460, Brazil. E-mail: danicazola@gmail.com Spoligotyping was performed in the present study to genotype Mycobacterium bovis isolates obtained from tissues of cattle that were positive in the comparative intradermal tuberculin test (CITT) in the state of Mato Grosso do Sul (Brazil). Tissue samples from 13 positive cattle from different municipalities of the state were cultured using a Stonebrink medium. The resulting colonies were subjected to Ziehl-Neelsen staining and all isolates exhibited the staining characteristics of AFB. The 13 isolates of AFB were identified by means of a multiplex PCR (mPCR) assay. The hsp65 gene was targeted for the identification of Mycobacterium spp., whereas the IS6110 insertion sequence was targeted for the identification of the Mycobacterium tuberculosis complex (MTC) and the rvd1rv2031c region was explored for the detection of Mycobacterium bovis. The spoligotyping assay was performed to genotype mycobacterial isolates. Of the 13 cattle, seven had at least one lesion suggestive of tuberculosis in the retropharyngeal, parotid and lung lymph nodes or lung. The remaining six exhibited no lesions suggestive of the disease. In the mPCR, 11 of the 13 isolates (84.6%) were positive for Mycobacterium spp., 8/13 (61.5%) were positive for the MTC and 7/13 (53.8%) were positive for M. bovis. Based on the spoligotyping, eight isolates were grouped into three different groups of genotypes and one isolate exhibited an orphan type. Four isolates exhibited spoligotype pattern SB0121, while two isolates were associated with the pattern SB1145, another two were associated with pattern SB0881 and one was associated with pattern SB0140. Spoligotyping confirmed the genetic diversity present among isolates found in the state of Mato Grosso do Sul. In addition, SB0121 was confirmed as the predominant profile.

• Mycobacterium bovis tuberculosis tuberculose bovina

Abstract in Portuguese:

RESUMO.- Cazola D.O., Jorge K.S.G., Zumárraga M.J., Souza-Filho A.F., Araújo F.R. & Osório A.L.A.R. 2015. [Identification and genotyping of Mycobacterium bovis from positive cattle in skin test for tuberculosis in the State of Mato Grosso do Sul, Brazil.] Identificação e genotipagem de Mycobacterium bovis em bovinos positivos no teste intradérmico para tuberculose em Mato Grosso do Sul. Pesquisa Veterinária Brasileira 35(2):141-147. Laboratório de Micobacteriologia e Biologia Molecular, Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Müller 2443, Campo Grande, MS 79074-460, Brazil. E-mail: danicazola@gmail.com Neste estudo, realizou-se genotipagem de isolados de Mycobacterium bovis, provenientes de amostras de tecidos de bovinos positivos no teste cervical comparativo (TCC) para tuberculose em Mato Grosso do Sul, por meio da técnica de spoligotyping. Tecidos de 13 bovinos positivos, oriundos de diferentes municípios do estado, foram cultivados em meio de Stonebrink. As colônias resultantes foram submetidas à coloração de Ziehl-Neelsen e todos os isolados apresentaram características tintoriais de BAAR. Os 13 isolados de BAAR foram identificados por PCR multiplex (mPCR). O gene hsp65 foi alvo para identificação de Mycobacterium spp, a sequência de inserção IS6110 foi alvo para identificação de complexo Mycobacterium tuberculosis (CMT) e a região rvd1rv2031c foi explorada para detecção de M. bovis. Os isolados micobacterianos foram genotipados pela técnica de spoligotyping. Dos 13 bovinos, sete tinham pelo menos uma lesão sugestiva de tuberculose em linfonodos retrofaríngeos, parotídeos e pulmonares ou no pulmão, e em seis não foram encontradas lesões visíveis sugestivas da doença. Na mPCR, 11/13 (84,6%) isolados foram positivos para Mycobacterium spp; 8/13 (61,5%) positivos para CMT e 7/13 (53,8%) positivos para M. bovis. Com base no spoligotyping, oito isolados de BAAR foram agrupados dentro de três diferentes agrupamentos de genótipos e uma amostra remanescente apresentou perfil único, sendo quatro isolados com padrão de espoligotipo SB0121, dois SB1145, dois SB0881 e um SB0140. A técnica de spoligotyping demonstrou que há diversidade genética entre os espoligotipos presentes no estado de Mato Grosso do Sul, embora predomine o perfil SB0121.

Abstract in English:

ABSTRACT.- Almeida R.F.C., Madruga C.R., Soares C.O., Fernandes M.C., Carvalho N.M., Jorge K.S.G. & Osório A.L.A.R. 2006. [Specific immune response of cattle to experimental sensibilization by inactivated Mycobacterium bovis and Mycobacterium avium.] Resposta imune específica de bovinos experimentalmente sensibilizados com inóculos inativados de Mycobacterium bovis e Mycobacterium avium. Pesquisa Veterinária Brasileira 26(4):195-200. Departamento de Medicina Veterinária da Universidade Federal de Mato Grosso do Sul, Cidade Universitária, Campo Grande, MS 79070-900, Brazil. E-mail: analudmv@nin.ufms.br The presumptive diagnosis of bovine tuberculosis is based on analysis of the immune response to micobacterial antigens. This experimental simulation of sensibilization by Mycobacterium bovis and Mycobacterium avium in cattle aimed to verify the immune response by both the cervical comparative test and the evolution of the specific production of gamma-interferon, and also to identify interference of unspecified reactions by M. avium on the test results. The results support that the experimental animals started a response of delayed hypersensitivity to the inactivated bacilli, and that both diagnostic tests for bovine tuberculosis were efficient for the identification of animals sensitized with M. bovis and for discrimination of reactions generated by inoculation of cattle with M. avium.

• Mycobacterium bovis Mycobacterium avium gamma-interferon tuberculin immune response

Abstract in Portuguese:

ABSTRACT.- Almeida R.F.C., Madruga C.R., Soares C.O., Fernandes M.C., Carvalho N.M., Jorge K.S.G. & Osório A.L.A.R. 2006. [Specific immune response of cattle to experimental sensibilization by inactivated Mycobacterium bovis and Mycobacterium avium.] Resposta imune específica de bovinos experimentalmente sensibilizados com inóculos inativados de Mycobacterium bovis e Mycobacterium avium. Pesquisa Veterinária Brasileira 26(4):195-200. Departamento de Medicina Veterinária da Universidade Federal de Mato Grosso do Sul, Cidade Universitária, Campo Grande, MS 79070-900, Brazil. E-mail: analudmv@nin.ufms.br The presumptive diagnosis of bovine tuberculosis is based on analysis of the immune response to micobacterial antigens. This experimental simulation of sensibilization by Mycobacterium bovis and Mycobacterium avium in cattle aimed to verify the immune response by both the cervical comparative test and the evolution of the specific production of gamma-interferon, and also to identify interference of unspecified reactions by M. avium on the test results. The results support that the experimental animals started a response of delayed hypersensitivity to the inactivated bacilli, and that both diagnostic tests for bovine tuberculosis were efficient for the identification of animals sensitized with M. bovis and for discrimination of reactions generated by inoculation of cattle with M. avium.