Mycobacterium avium ssp. paratuberculosis (MAP) is the etiological agent of paratuberculosis, a chronic granulomatous enteritis that affects all ruminants worldwide. Some researchers have indicated a possible role of MAP in Crohn's disease. Despite extensive research and large and important advances in the past few decades, the etiology of Crohn's disease remains indefinite. The most probable transmission route of MAP from animals to humans is milk and dairy products. Mycobacterium avium ssp. paratuberculosis has already been detected in milk samples worldwide, and some studies have reported that MAP is resistant to pasteurization. In Brazil, MAP has been reported in raw milk samples; however, Brazilian retail pasteurized milk has not yet been tested for viable MAP. The aim of this study was to investigate MAP in pasteurized milk in the region of Viçosa (Minas Gerais, Brazil). Thirty-seven samples were collected and processed for culture of MAP. One colony similar to MAP was observed and confirmed by IS900-nested PCR and sequencing. Analysis revealed 97 to 99% identity with the MAP K-10 strain. This study is the first report of the presence of MAP in retail pasteurized whole milk in Brazil.

This study does not provide evidence for a role of MAP in the etiology of CD, although MAP DNA was detected in all three patient groups. This is the first report of MAP presence in human intestinal biopsies in Brazil.

The multidrug efflux system in bacteria can reduce antibiotic concentration inside the cell, leading to failure in the treatment of bacterial diseases. This study evaluated the influence of two efflux pump inhibitors (EPIs), phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP), on the gene expression of three multidrug efflux systems, AcrAB, AcrEF and EmrAB in Escherichia coli bovine mastitis isolates resistant to ampicillin and sulfamethoxazole/trimethoprim simultaneously. Each isolate had at least three multidrug efflux system genes. The acrA and acrB had the lowest expression levels in all treatments, while the emrA or emrB showed the highest expression levels in the presence of ampicillin, sulfamethoxazole/trimethoprim, PAβN and NMP. EPIs also contributed to the decrease in arcF expression when used in combination with ampicillin treatment. Since PAßN showed stronger effects than NMP, it may serve as an alternative to assist in the antimicrobial therapy of mastitis.

RESUMOMycobacterium avium subesp. paratuberculosis (MAP) é o agente etiológico da paratuberculose em ruminantes domésticos e silvestres. Em caprinos e ovinos causa uma enterite granulomatosa crônica com emagrecimento progressivo seguido de morte, raramente a diarreia é observada. Nesse aspecto, a doença é considerada uma ameaça mundial aos rebanhos, pois pode permanecer no estádio subclínico por anos, manifestando perdas indiretas na produção animal e na disseminação do agente. Além disso, existem relatos da possível relação de MAP com a doença de Crohn, determinando, assim, a sua relevância na saúde pública. O Brasil não dispõe de dados quantificando as reais perdas produtivas nos rebanhos acometidos pela doença, e poucas informações do comprometimento de caprinos e ovinos no país são relatadas. Assim, este artigo busca revisar a paratuberculose em pequenos ruminantes domésticos. PALAVRAS-CHAVE:Mycobacterium avium subesp. paratuberculosis, ovinos, caprinos. ABSTRACT PARATUBERCULOSIS IN SMALL DOMESTIC RUMINANTS. Mycobacterium avium subsp.paratuberculosis (MAP) is the causative agent of paratuberculosis in domestic and wild ruminants. In sheep and goats it causes a chronic granulomatous enteritis with progressive emaciation and death, diarrhea rarely being observed. In this aspect, the disease is considered a worldwide threat to livestock, as it may remain subclinical for years, with indirect losses in production and agent dissemination. In addition, there are reports of a possible relationship with the agent of Crohn's disease, so it is also of relevance to public health. Brazil does not have any data quantifying the actual production losses in herds affected by the disease, and few details of the involvement of goats and sheep in the country have been reported. Thus, this paper aims to review the occurrence of paratuberculosis in flocks of domestic small ruminants. KEY WORDS: Mycobacterium avium subsp. paratuberculosis, sheep, goats.A paratuberculose é uma doença bacteriana contagiosa crônica do trato intestinal que afeta predominantemente ruminantes domésticos e silvestres (Chiodini et al., 1984;Clarke, 1997; ayele et al., 2001;Mota et al., 2010), causada pelo Mycobacterium avium subesp. paratuberculosis (MAP), da família Mycobacteriaceae. Estes são bastonetes aeróbicos, imóveis, catalase positiva, sendo considerados Gram positivos (tiMMs et al., 2011). Por apresentarem grande quantidade de ácido micólico e lipídios na parede celular, coram-se melhor pela técnica de Ziehl-Neelsen, onde a fucsina carbólica se liga aos lipídeos da parede celular, resistindo ao descorante álcool-ácido, sendo classificados como bacilos álcool-ácido resistentes (BAAR) (Quinn et al., 2005). Essa característica lipídica em sua parede celular confere elevada resistência no meio ambiente. Whittington et al. (2004) demonstraram que MAP pode permanecer viável em solos sombreados por mais de 55 semanas, sendo resistentes à maioria dos desinfetantes comumente utilizados (Collins, 2003). Recentemente, foi verificado que MAP pode também uti...

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.