Micobacterioses de interesse veterinário /Tuberculose animal

Paula Ristow, Ana Bárbara Freitas Rodrigues, Leila Souza Fonseca, Waltee Martin Roland Oelemann, Guilherme Nunes Souza, Carla Dray Marassi, Eulógio Carlos Queiróz de Carvalho and Walter Lilenbaum

ABSTRACT

Paratuberculosis (PTB) is a chronic enteritis deter- mined by Mycobacterium avium subsp. paratuberculosis (Map) that affects ruminants. Three crossbred dairy cattle with clinical PTB were necropsied; tissue samples were collected and processed for histopathology and culture. Intestinal lesions were characterized in three levels of severity (mild, moderate and severe) by gross examination. Gross examination, microscopy and tissue culture were an- alyzed and compared. Mean tissue culture sensitivity was 66.6%. Map was recovered from 42.8% of intestinal mild lesions, 55.5% of intestinal moderate lesions, and 100% of severe intestine lesions. The results indicate a significant correlation between the level of lesions severity and the isolation of Map.

KEY WORDS: Cattle, Johne’s disease, Map, paratuberculosis, pathology.

Attachments:

1337_1148-18929-3-PB.pdf

[ ]

170 kB

Walter Lilenbaum, Guilherme Nunes de Souza, Leila de Souza Fonseca

Abstract

With the purpose of identifying management factors that may be influencing the prevalence of bovine tuberculosis under tropical conditions, namely in Rio de Janeiro, Brazil, 1632 cows were tested through the single cervical tuberculin test. A questionnaire was completed for each herd. A total of 207 positive reactions were observed, corresponding to 12.7% of the studied cattle. The main factors observed that may be influencing the prevalence of bovine tuberculosis on those farms were the absence or reduced veterinary assistance and the herd size. The presence of adequate cattle houses and the highly intensive management are also considered to be likely to influence the prevalence of the disease. Under tropical conditions, a tuberculosis control program, in addition to the test-and-slaughter control method, should include an investigation of herd management practices to try to identify factors that are likely to influence the prevalence of the disease.

Keywords: tuberculosis, bovine, epidemiololgy, M. bovis, Brazil.

Attachments:

1334_arquivo_09.pdf

[ ]

22 kB

W. Lilenbaum, C. D. Marassi, R. Varges, L. Medeiros, W. M. R. Oelemann and L. S. Fonseca

Abstract

The interference of bovine tuberculosis (TB) on the efficacy of paratuberculosis (PTB) diagnostic tests has been evaluated. A group of 32 tuberculous cows identified by both intradermal tests and gamma-interferon assay, 16 of them confirmed by the recovery of M.bovis from tissues, was tested by three different PTB- ELISAs, being two commercials and one in-house. The rest of the adult animals of the herds, totalizing 216 TB-negative animals, were also tested as a control group. Fecal culture for PTB was negative in all animals, but seven (21.8%) tuberculous cows produced false-positive reactions when tested by various PTB-ELISAs, leading to a misdiagnosis. Tuberculosis impairs the specificity of serological tests for paratuberculosis diagnosis and should be considered for the reliability of PTB control programs.

Carla Dray Marassi; Marley Silva; Walter Martin Roland Oelemann; Leila de Souza Fonseca; Paula Ristow; Walter Lilenbaum

ABSTRACT

ELISAs for paratuberculosis employ a preadsorption step with Mycobacterium phlei to diminish unspecific reactions As M. fortuitum is one of the most frequent environmental mycobacteria, the purpose of this pilot study was to evaluate its use as an alternative for the preadsorption in ELISAs for paratuberculosis. Results suggest that M. fortuitum can be an alternative instead of or associated to M. phlei with comparable results (κ > 0.8) to conventional ELISAs using M. phlei as a preadsorption antigen.

Key-words: Mycobacteria, ELISA, M. fortuitum, M. phlei

Attachments:

1336_arq19.pdf

[ ]

269 kB

Eduardo Eustáquio de Souza Figueiredo; Ricardo Cezar Tavares Carvalho; Flávia Galindo Silvestre; Walter Lilenbaum; Leila Sousa Fonseca; Joab Trajano Silva; Vânia Margaret Flosi Paschoalin

ABSTRACT

Detection of tuberculosis in cattle relies on the intradermal tuberculin test (ITT), but a definitive diagnosis requires identification of the pathogen after the animal is slaughtered. DNA in nasal swabs from 50 cows was analyzed by m-PCR, targeting for the RvD1-Rv2031c and IS6110 sequences. M. bovis was identified in two of 34 tuberculous cows (5.9%). The use of mPCR of nasal swabs as an in vivo diagnostic tool for bovine tuberculosis is suggested.

Key words: Mycobacterium bovis, multiplex-PCR, nasal swab, bovine tuberculosis

Attachments:

1345_V41n2a20.pdf

[ ]

234 kB

Carla Dray Marassi; Janete da Silva Gonzaga; Paula Ristow; Rachel Ferreira; Leila Souza Fonseca; Walter Oelemann; Walter Lilenbaum

ABSTRACT

An in-house PPA-ELISA was compared to a commercial ELISA using a panel of 108 serum samples. In relation to commercial test, in-house assay presented 100% of sensitivity and 83.5% of specificity and a high concordance (κ> 0.5), which demonstrates that the in-house assay is a valuable tool for use in developing countries.

Carla D. Marassi, Jim McNair, John Pollock, Paula Ristow, Leila S. Fonseca, Walter M.R. Oelemann, Walter Lilenbaum

Walter Lilenbaum; Rachel Ferreira; Carla Dray Marassi; Paula Ristow; Walter Martins Roland Oelemann; Leila de Souza Fonseca

ABSTRACT

Forty-four cows from five herds infected with tuberculosis (TB) and without paratuberculosis (PTB), and 21 cows from a herd without either infection were studied. The cattle presented concordant results in both the skin test and γ-interferon assay for TB and two commercial ELISAs for PTB. Animals were divided according to TB test results into Group A with 28 TB-infected animals, Group B with 16 TB-negative animals from infected herds, and Group C with 21 TB-negative cows from a tuberculosis-free herd (which were used as controls). Twenty of 28 animals from Group A (71.4%), 6/16 from Group B (37.5%) and none from Group C were reactive to PTB ELISAs, suggesting that these commercial kits were unable to distinguish between PTB and TB. It is proposed that natural occurring TB strongly interferes in the diagnosis of PTB and that commercial ELISAs cannot be considered reliable tools in the diagnosis of paratuberculosis in tuberculosis-infected herds.