Seroprevalence of Brucella ovis-epididymitis, smooth-Brucella, leptospirosis, toxoplasmosis, and Maedi-Visna in sheep slaughtered in Minas Gerais State, Brazil / Soroprevalência de Brucella ovis, Brucella lisa, leptospirose, toxoplasmose e Maedi-Visna em ovinos abatidos em Minas Gerais, Brasil

The present study aimed to estimate the prevalence of antibodies against Brucella ovis-epididymitis, smooth-Brucella, leptospirosis, toxoplasmosis and Maedi-visna in sheep slaughtered in Minas Gerais, Brazil and to study their simultaneous occurrence, including caseous lymphadenitis, at sheep and flock levels. The study was conducted at a sheep slaughterhouse with Federal Inspection Service. Sera from 594 animals from 21 flocks were collected, in 2007. The agar gel immunodiffusion (AGID) was employed to detect anti-B. ovis and anti-Maedi Visna antibodies, whereas Rose Bengal (RB) and the 2-mercaptoethanol test (2ME) were used to test anti-smooth Brucella antibodies. For the detection of anti-Leptospiraantibodies, sera were examined by microscopic agglutination test (MAT), while for the detection of IgG antibodies to Toxoplasma gondii ELISA was used. Prevalence of antibodies against smooth Brucella, B. ovis-epididimitis, Leptospiraspp., toxoplasmosis and Maedi-Visna found in sheep from Minas Gerais was 0.00%, 24.04%, 25.96%, 10.46% and 3.08%, respectively; whereas the seroprevalence in flocks was 0.00%, 80.95%, 90.48%, 71.43% and 23.81%, respectively. Moreover, when data on antibodies anti-Corynebacterium pseudotuberculosis, previously obtained, were included, about 60% of the flocks showed animals that were exposed to four or more of the studied agents. However, only 25.47% of the sheep exhibited simultaneously antibodies against more than one pathogen. Thus, data from the present study on sheep slaughtered in Minas Gerais, Brazil, showed no antibodies to smooth-Brucella and a low frequency of antibodies anti-Maedi Visna lentivirus, and a high and widespread seroprevalence of B. ovis, Leptospira spp., and T. gondii among animals and flocks.(AU)

O presente estudo teve como objetivo estimar a prevalência de anticorpos contra Brucella ovis (epididimite ovina), Brucellalisa, leptospirose, toxoplasmose e Maedi-visna em ovinos abatidos em Minas Gerais, Brasil, e estudar sua ocorrência simultânea, incluindo linfadenite caseosa, nos ovinos e nos rebanhos. O estudo foi realizado em um abatedouro de ovinos com Serviço de Inspeção Federal. Soros de 594 animais de 21 rebanhos foram coletados, em 2007. A imunodifusão em gel de ágar (IDGA) foi empregada para detectar anticorpos anti-B. ovis e anticorpos anti-Maedi Visna, enquanto o teste do antígeno acidificado tamponado (AAT) e o teste de 2-mercaptoetanol (2ME) foram utilizados para testar anticorpos anti-Brucella lisa. Para a detecção de anticorpos anti-Leptospira, os soros foram examinados pelo teste de aglutinação microscópica (MAT), enquanto que para a detecção de anticorpos IgG para Toxoplasma gondii, foi usado o ELISA. A prevalência de anticorpos anti-Brucella lisa, B. ovis, Leptospira spp., toxoplasmose e Maedi-Visna encontrados em ovinos de Minas Gerais foi de 0,00%, 24,04%, 25,96%, 10,46% e 3,08%, respectivamente; enquanto a soroprevalência em rebanhos foi de 0,00%, 80,95%, 90,48%, 71,43% e 23,81%, respectivamente. Além disso, quando dados de anticorpos anti-Corynebacterium pseudotuberculosis, previamente obtidos, foram incluídos, cerca de 60% dos rebanhos apresentaram animais expostos a quatro ou mais dos agentes estudados. No entanto, apenas 25,47% dos ovinos exibiram simultaneamente anticorpos contra mais de um patógeno. Assim, os dados do presente estudo sobre ovinos abatidos em Minas Gerais, Brasil, mostram que ausência de anticorpos anti-Brucella lisa e baixa frequência de anticorpos anti-Maedi Visna, e uma soroprevalência alta e generalizada de B. ovis, Leptospira spp. e T. gondii entre animais e rebanhos.(AU)

Diagnostic comparison of Corynebacterium pseudotuberculosis through microbiological culture and PCR in sheep samples / Comparação diagnóstica de Corynebacterium pseudotuberculosis pelo cultivo microbiológico e PCR em amostras ovinas

Caseous lymphadenitis is a chronic infectious disease caused by Corynebacterium pseudotuberculosis , which is a bacterium responsible for a great number of economic losses on goat and sheep production. It is characterized by the formation of abscesses in superficial lymph nodes and in internal organs and lymph nodes. This study aimed at determining the agreement between microbiological culture and PCR in the identification of C. pseudotuberculosis , in samples collected from animals in slaughterhouses and in animals that presented lymph node enlargement in field conditions. From the 202 samples analyzed through microbiological culture, 113 (56%) were positive for Corynebacterium sp.; from these positive samples, 38 (34%) were identified as C. pseudotuberculosis by microbiological culture. From the amount of samples, 110 (54%) were positive and 92 (46%) were negative in the PCR. Kappa index (0.193) presented a weak agreement between PCR and microbiological culture. We concluded that molecular diagnosis (PCR) in clinical samples proved to be more efficient, reproducible, and faster than the microbiological culture, both on clinical samples analyses and in the confirmation of C. pseudotuberculosis in colonies that were classified by Corynebacterium genus. Thus, the present study demonstrated the importance of PCR to confirm C. pseudotuberculosis diagnosis, and the best contribution for the epidemiological surveillance of the disease in sheep.(AU)

A linfadenite caseosa é uma doença infectocontagiosa crônica, causada pelo agente etiológico Corynebacterium pseudotuberculosis , que é uma bactéria responsável por grandes perdas econômicas na produção de ovinos e caprinos. Caracteriza-se pela formação de abscessos em nódulos linfáticos superficiais e em órgãos internos e linfonodos. O presente trabalho teve por objetivo verificar a concordância entre as metodologias de isolamento microbiológico com a PCR na identificação do C. pseudotuberculosis , em amostras clínicas colhidas em abatedouros e em animais que apresentavam aumento de linfonodo em condições de campo. Das 202 amostras analisadas no cultivo microbiológico, 113 (56%) foram positivas para o gênero Corynebacterium sp., e 38 (34%) colônias foram identificadas como C. pseudotuberculosis por meio de cultura microbiológica. Das amostras clínicas extraídas, 110 (54%) foram positivas e 92 (46%) foram negativas na PCR. A concordância estimada entre as técnicas de PCR e o cultivo microbiológico pelo indicador Kappa foi considerada fraca (0,193). Concluímos que o diagnóstico molecular (PCR) provou ser mais eficiente, rápido e com reprodutibilidade quando comparado ao cultivo microbiológico das amostras clínicas bem como da confirmação do C. pseudotuberculosis de colônias pertencentes ao gênero Corynebacterium . Dessa forma, o presente trabalho demonstrou a importância do uso da PCR na confirmação diagnóstica do C. pseudotuberculosis , visando contribuir com a melhoria da vigilância epidemiológica da doença em ovinos.(AU)

Multiplex polymerase chain reaction to identify and determine the toxigenicity of Corynebacterium spp with zoonotic potential and an overview of human and animal infections

Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.