Cytokine gene expression and molecular detection of Mycobacterium avium subspecies paratuberculosisin organs of experimentally infected mice / Expressão de citocinas e detecção molecular de Mycobacterium avium subspecies paratuberculosis em órgãos de camundongos infectados experimentalmente

Mycobacterium avium subspecies paratuberculosis (MAP) can infect ruminants and remain subclinical for long periods within herds. The identification of organs that are more susceptible to infection and the evaluation of cytokine expression at the site of infection are important to understand the pathogenesis of MAP. In this study, the probability of detection of MAP-DNA and the expression of cytokines in organs of C57BL/6 mice infected intraperitoneally for 120 days were evaluated. Among the evaluated organs, the spleen (85%), colon (75%) and liver (60%) had the highest frequency of positivity. When compared these frequencies between organs, it has been found that the spleen had 1.54 times as likely to be positive in relation to the ileum, and 2.0 times more likely in relation to the Peyer's patches. In addition, at 60 days post-infection, the spleen and the liver were responsible for upregulation of IFN-γ , and the ileum by TNF-α and IL-4. The results indicate that the spleen is the best organ for evaluating an experimental infection by MAP, especially in the initial stages of the infection. Moreover, it showed that the spleen, liver and ileum have a direct role in the inflammatory response in experimental models.(AU)

Mycobacterium avium subespécie paratuberculosis (MAP) pode infectar ruminantes e permanecer subclínica por longos períodos nos rebanhos. A identificação de órgãos mais susceptíveis à infecção e a avaliação da expressão das citocinas no local da infecção são importantes para compreender a patogênese de MAP. Neste estudo foi avaliada a probabilidade de detecção de DNA de MAP e a expressão de citocinas em órgãos de camundongos C57BL/6 infectados por via intraperitoneal durante 120 dias. Dentre os órgãos avaliados, o baço (85%), cólon (75%) e fígado (60%) tiveram as maiores frequências de positividade. Quando comparadas essas frequências entre os órgãos, verificou-se que o baço teve 1,54 vezes mais probabilidade de ser positivo em relação ao íleo, e 2,0 vezes mais probabilidade em relação às placas de Peyer. Além disso, aos 60 dias pós infecção, o baço e o fígado foram responsáveis pela maior expressão de IFN-γ e o íleo pela TNF-α e IL-4. Os resultados indicam que o baço é o melhor órgão para avaliar uma infecção experimental por MAP, principalmente nos períodos iniciais da infecção. Além disso, demonstrou que o baço, fígado e íleo têm importância direta na resposta inflamatória de modelos experimentais.(AU)

The effect of Mycobacterium avium subspecies paratuberculosis exposure on animal health

Background: Johne's disease is an incurable wasting condition that affects ruminant and non-ruminant animals. Each year, Johne's is responsible for losses in the billions of dollars in the United States cattle industry alone. Mycobacterium avium subspecies paratuberculosis (MAP) is the microorganism responsible for Johne's disease. MAP can spread very fast among animals, and this patogen has been isolated across the world and in several different animal species including humans. Therefore, MAP is classified as having a major impact on both animal and human health, and therefore the economy. MAP has also been associated with Crohn's disease in humans, which necessitates great concerns regarding public health. The objective of this literature review is to identify problems and challenges associated with this illness and highlight possible approaches to minimize the economic losses and the incidence of Johne's, two avenues to reduce human exposure with this pathogen. Review: Following ingestion and exposure to MAP, the bacterium will infect the host through the ileum and than it will proliferate inside of host-cells; MAP can therefore be considered an intracellular parasite. After infection, this pathogen goes to a latency period that can be from months to several years without causing the presence of clinical signs in the host. This bacteria can cause an inflammatory response in the intestine, decreasing the ability of the animal to absorb nutrients. Depending on the level of infection bacteria strain and the genetic composition of the animal, individuals can become or not infected, if infected they can shed variable levels of MAP into the environment, increasing the exposure to other animals. Thus, it is of importance to eliminate MAP infected animals from herds ; aiming to reduce the environment contamination with this bacteria. Several chromosomal regions have been associated and linked with MAP infection in cattle. It is proposed that Johne's disease has a polygenic effect with multiple genes involved in the process of susceptibility and tolerance to the disease. Selection for animals that are tolerant to Johne's disease has also been proposed, whereby tolerance was defined as the ratio of MAP tissue infection and MAP fecal shedding. Animals that are shedding low or no levels of MAP in the environment were considered tolerant, thus are preferred in comparison with the ones that are eliminating high levels of MAP. Some positional and functional candidate genes have being identified and explored. The major problem with genetic studies with Johne's disease is the correct classification of the phenotype. ELISA, PCR and fecal culture are methods of testing for Johne's disease but variation exists regarding the degree of accuracy and effectiveness for each test, as discussed further within this review. Discussion: In this study, we presented the importance of preventive control of MAP transmission amongst animals and humans, respectively. Several approaches to reduce the incidence of this illness among animals were evaluated; however the number of infected animals is still increasing annually, especially within dairy herds. Genetic selection for animals that are less susceptible might be one solution to reduce the spread and contamination of other animals with these bacteria. This necessitates the better understanding of the genes involved with host-immune-defense mechanisms for development of an accurate selection method. Questions related to the zoonotic potential of MAP, the causative agent of Johne's disease, and Crohn's disease in humans is still of great concern to the population, therefore efforts to control and eradicate this disease are needed.

A seroepidemiological survey of Mycobacterium avium subsp. paratuberculosis in sheep from North of Portugal / Rastreio seroepidemiológico de Mycobacterium avium subsp. paratuberculosis em ovinos no Norte de Portugal

The aim of this study was evaluate the risk factors for Mycobacterium avium subsp. paratuberculosis (Map) seroprevalence in sheep in the North of Portugal. The effects on seroprevalence of several variables such as individual characteristics, management practices, farm characteristics, animal health, and available veterinary services were evaluated. This information was then used in a multivariable logistic regression model in order to identify risk factors for Map seropositivity. Univariable analysis was used to screen the variables used in the logistic regression model. Variables that showed p values of <0.15 were retained for the multivariable analysis. Fifteen variables were associated with paratuberculosis in univariable analysis. The multivariable logistic regression model identified a number of variables as risk factors for seropositivity like sheep pure local and/or a cross of a local breed (OR=2.02), herd size with 31-60 head (OR=2.14), culling during the Spring-Summer season (OR=1.69) and the use of an anti-parasitic treatment such as Ivermectin as the only anti-parasitic medication (OR=5.60). Potential risk factors identified in this study support current recommendations for the control of paratuberculosis.(AU)

Neste trabalho efectuou-se o estudo dos factores associados à seroprevalência da infecção ovina por Mycobacterium avium subspecies paratuberculosis (Map). Foram investigadas variáveis como as características individuais, práticas de maneio, características da granja, saúde animal e intervenções de sanidade efectuadas no animal. A análise multivariada de regressão logística foi usada para identificar estes factores associados com a seroprevalência da infecção. De acordo com os resultados da análise univariada associaram-se, com o resultado positivo à infecção (p<0,15), 15 variáveis. Após a aplicação do modelo de análise multivariada encontraram-se quatro factores de risco com significância estatística: rebanhos de raças autóctones e seus cruzamentos (OR=2,02); tamanho do efectivo entre 31-60 animais (OR=2,14); época de abate na Primavera-Verão (OR=1,69); uso de ivermectina como único antiparasitário (OR=5,60). Os potenciais factores de risco identificados neste estudo suportam as recomendações currentes para o controlo da paratuberculose.(AU)

Paratuberculosis in a dairy Gyr herd in the State of Paraíba, Brazil / Paratuberculose em um rebanho Gir leiteiro no Estado da Paraíba Brasil

This paper describes the clinical, pathological, and microbiologic aspects of paratuberculosis (Johne's disease) in a dairy Gyr herd in the State of Para�ba, northeastern Brazil. An eight years old cow with chronic unresponsive diarrhea was clinically examined and euthanized for pathological evaluation. Fecal samples from all 160 animals over 12 months of age from the herd were collected for isolation of Mycobacterium avium subsp. paratuberculosis. Clinically, the index case cow was severely dehydrated, cachectic, with profuse mucous diarrhea. The main post-mortem findings were emaciation and thickened intestinal wall. Microscopically, the intestinal lamina propria and submucosa were infiltrated by macrophages, epithelioid cells, and Langhans giant cells with numerous alcohol-acid resistant bacilli in the cytoplasm. Two fecal samples displayed growth in slants of Herrold's egg-yolk agar supplemented with mycobactin J, 150 days after incubation. No growth was noticed in slants without mycobactin J. Microscopic examination of the isolated microorganisms stained by Ziehl-Neelsen revealed considerable amounts of alcohol-acid resistant bacilli, morphologically compatible with Mycobacterium spp. Based on the clinical signs, gross and histological lesions, growth time, bacterial morphology in Ziehl-Neelsen staining, and dependence of mycobactin J, the first diagnosis of paratuberculosis in Zebu cattle was made.(AU)

Objetivou-se descrever os aspectos clínicos, anátomo-histopatológicos e microbiológicos da paratuberculose em um rebanho Gir leiteiro no Estado da Paraíba. Uma vaca de oito anos que apresentava diarréia persistente, refratária a tratamento foi necropsiada para estudo anátamo-histopatológico. Também foram coletadas amostras de fezes de todos os 160 animais do plantel, com idade superior a 12 meses, para tentativa de isolamento de Mycobacterium avium subsp. paratuberculosis. Ao exame clínico, o animal caso índice apresentou caquexia, diarréia profusa e desidratação grave. À necropsia, o animal apresentou-se emaciado e, ao exame detalhado do trato digestivo, foi observado espessamento da parede e superfície mucosa do íleo e intestino grosso. À microscopia, verificou-se intensa infiltração de macrófagos espumosos associado a raras células epiteliódes e gigantes do tipo Langerhans na lâmina própria e submucosa. À coloração de Ziehl-Neelsen foram observadas miríade de bacilos álcool-ácido resistentes no citoplasma destas células. Houve crescimento de colônias bacterianas em duas das 160 amostras de fezes após 150 dias de incubação em tubos com meio Herrold's egg-yolk suplementados com micobactina J e ausência de crescimento nos tubos com mesmo meio, mas sem suplementação. Os microrganismos isolados foram corados pelo Ziehl-Neelsen observando-se presença de grande quantidade de bacilos álcool-ácido resistente, com morfologia compatível ao gênero Mycobacterium. Baseado na história clínica, achados anátomo-histopatológicos e histoquímicos (Ziehl-Neelsen), e microbiológicos, firmou-se o primeiro diagnóstico de paratuberculose em Zebu na Paraíba.(AU)

Pesquisa de Mycobacterium avium subsp. paratuberculosis em caprinos e ovinos provenientes de matadouro na Paraíba

A paratuberculose é uma doença infectocontagiosa, crônica, incurável que atinge diversas espécies de animais, provocando uma enterite e linfadenite granulomatosa crônica, caracterizada por síndrome da má absorção, diarreia e perda de peso, influenciando na redução da produtividade e causando grande impacto na economia. Causada pelo Mycobacterium avium (subsp.) paratuberculosis (MAP), que também é considerada como o agente causador da Doença de Crohn em humanos. Esta dissertação é formada por dois artigos originais. O primeiro submetido à revista Arquivos do Instituto Biológico que faz uma explanação sobre a paratuberculose no Brasil com enfoque em caprinos e ovinos; definição, etiologia, patogenia, sinais clínicos particulares destas espécies, lesões macro e microscópicas, diagnóstico e fatores de risco associado a prevenção da doença. O segundo capítulo foi submetido à revista Pesquisa Veterinária Brasileira abordando a ocorrência do Map em caprinos e ovinos provenientes de matadouros na Paraíba. Onde amostras de linfonodos mesentéricos e válvulas ileocecal foram coletadas de 151 animais (77 ovinos e 74 caprinos) para a realização do diagnóstico mediante o exame histopatológico utilizando as colorações de Hematoxilina e Eosina e Ziehl- Neelsen, a Reação em Cadeia Polimerase (PCR). Na histopatologia pela coloração de H&E, observaram-se inflamações inespecíficas não condizentes com lesões de paratuberculose. Não foram visualizados bacilos álcool-ácido-resistentes nas amostras, entretanto, pela a técnica da PCR, 15,6% dos ovinos estudados e 12,16% dos caprinos foram positivos para o Map.

Paratuberculosis is an infectious disease, chronic, incurable that affects several species of animals, causing a chronic granulomatous enteritis and lymphadenitis, characterized by malabsorption syndrome, diarrhea and weight loss, reduced productivity in influencing and causing great impact on the economy. Caused by Mycobacterium avium (subsp.) paratuberculosis (Map), which is also considered as the causative agent of Crohn's disease in humans. This dissertation consists of two original articles. The first submitted to the journal Archives of Biology Institute which is an explanation of paratuberculosis in Brazil with a focus on sheep and goats; definition, etiology, pathogenesis, clinical signs of these particular species, gross and microscopic lesions, diagnosis and risk factors associated with prevention the disease. The second chapter was submitted to the journal Veterinary Research addressing the occurrence of the Map in goats and sheep from abattoirs in Paraíba. Where samples of mesenteric lymph nodes and ileocecal valves were collected from 151 animals (77 sheep and 74 goats) for the diagnosis by histopathology using hematoxylin and eosin staining and Ziehl-Neelsen, and the Polymerase Chain Reaction (PCR). In histopathology by H & E staining, there were no nonspecific inflammatory lesions consistent with paratuberculosis. There were visualized acid- fast bacilli in resistant samples, however, by the PCR technique, 15.6% studied in sheep and goats 12.16% were positive for Map.

Pesquisa de Mycobacterium avium subsp. paratuberculosis em caprinos e ovinos provenientes de matadouro na Paraíba

A paratuberculose é uma doença infectocontagiosa, crônica, incurável que atinge diversas espécies de animais, provocando uma enterite e linfadenite granulomatosa crônica, caracterizada por síndrome da má absorção, diarreia e perda de peso, influenciando na redução da produtividade e causando grande impacto na economia. Causada pelo Mycobacterium avium (subsp.) paratuberculosis (MAP), que também é considerada como o agente causador da Doença de Crohn em humanos. Esta dissertação é formada por dois artigos originais. O primeiro submetido à revista Arquivos do Instituto Biológico que faz uma explanação sobre a paratuberculose no Brasil com enfoque em caprinos e ovinos; definição, etiologia, patogenia, sinais clínicos particulares destas espécies, lesões macro e microscópicas, diagnóstico e fatores de risco associado a prevenção da doença. O segundo capítulo foi submetido à revista Pesquisa Veterinária Brasileira abordando a ocorrência do Map em caprinos e ovinos provenientes de matadouros na Paraíba. Onde amostras de linfonodos mesentéricos e válvulas ileocecal foram coletadas de 151 animais (77 ovinos e 74 caprinos) para a realização do diagnóstico mediante o exame histopatológico utilizando as colorações de Hematoxilina e Eosina e Ziehl- Neelsen, a Reação em Cadeia Polimerase (PCR). Na histopatologia pela coloração de H&E, observaram-se inflamações inespecíficas não condizentes com lesões de paratuberculose. Não foram visualizados bacilos álcool-ácido-resistentes nas amostras, entretanto, pela a técnica da PCR, 15,6% dos ovinos estudados e 12,16% dos caprinos foram positivos para o Map.(AU)

Paratuberculosis is an infectious disease, chronic, incurable that affects several species of animals, causing a chronic granulomatous enteritis and lymphadenitis, characterized by malabsorption syndrome, diarrhea and weight loss, reduced productivity in influencing and causing great impact on the economy. Caused by Mycobacterium avium (subsp.) paratuberculosis (Map), which is also considered as the causative agent of Crohn's disease in humans. This dissertation consists of two original articles. The first submitted to the journal Archives of Biology Institute which is an explanation of paratuberculosis in Brazil with a focus on sheep and goats; definition, etiology, pathogenesis, clinical signs of these particular species, gross and microscopic lesions, diagnosis and risk factors associated with prevention the disease. The second chapter was submitted to the journal Veterinary Research addressing the occurrence of the Map in goats and sheep from abattoirs in Paraíba. Where samples of mesenteric lymph nodes and ileocecal valves were collected from 151 animals (77 sheep and 74 goats) for the diagnosis by histopathology using hematoxylin and eosin staining and Ziehl-Neelsen, and the Polymerase Chain Reaction (PCR). In histopathology by H & E staining, there were no nonspecific inflammatory lesions consistent with paratuberculosis. There were visualized acid- fast bacilli in resistant samples, however, by the PCR technique, 15.6% studied in sheep and goats 12.16% were positive for Map.(AU)