Ce travail de thèse intitulé «Evaluation de marqueurs génétiques du complexe Mycobacterium tuberculosis combinée à l'utilisation d'outils bioinformatiques: apport en épidémiologie et phylogénie de la tuberculose» a consisté en la sélection et l'évaluation de marqueurs minisatellites dans le cadre d'études épidémiologiques et phylogénétiques du bacille tuberculeux, Une première partie a ainsi porté sur l'épidémie de tuberculose en Guadeloupe, Martinique, et Guyane française ainsi que dans un pays continental à faible incidence de tuberculose, la Suède, Les résultats montrent les disparités existant entre les populations de patients tuberculeux des 3 départements français d'Amérique (DFA) ainsi que les similitudes génotypiques existant entre les bacilles tuberculeux. Par ailleurs le rôle majeur joué par les cas d'importation dans l'épidémie de tuberculose a été montré aussi bien dans les DFA qu'en Suède. Nous nous sommes ensuite intéressés à une utilisation optimale des minisatellites pour une meilleure discrimination de la famille génotypique émergeante « Beijing» circulant au Japon (Osaka, Kobe et Okinawa), ainsi qu'en Russie. Nous avons constaté le faible pouvoir discriminant du format classique 12-locus MIRU (Mycobacterial lnterspersed Repetitive Units) et proposons plusieurs nouvelles stratégies de typage basées plusieurs marqueurs minisatellites incluant certains locus hypervariables. Enfin, dans un troisième volet, nous avons étudié la diversité génétique des bacilles tuberculeux circulant actuellement dans la Caraïbe. laquelle semble refléter le passé historique très particulier de cette zone géographique au croisement d'une multitude de peuplements. / This thesis entitled "Evaluation of genetic markers of Mycobacterium tuberculosis combined with the use of bioinformatics tools: input for epidemiology and phylogeny of tuberculosis" deals with the selection and evaluation of minisatellite markers in the context of epidemiological and phylogenetic studies of the tubercle bacillus M. tuberculosis. The first part of the present work has focused on the epidemic of tuberculosis in Guadeloupe, Martinique and French Guiana as well as in a low incidence continental country, i.e Sweden. The results show differences between populations of TB patients in the three French Departments of America and similarities between the genotypes of the circulating tubercle bacilli Moreover, results highlight the important role played by imported cases for TB epidemic the three French departments of America and Sweden. ln a second part, minisatellite markers have been evaluated for a better discrimination of strains of the emerging genotype "Beijing" circulating in Japan (Osaka, Kobe and Okinawa), and Russia. A low discriminatory power of classical format 12-locus MIRU (Mycobacterial lnterspersed Repetitive Units) was observed and new combinations of minisatellites have also been proposed including hypervariable locus. Finally, the genetic diversity of tubercle bacilli circulating in the Caribbean was investigated which currently seem to reflect historical past of this very special region at the intersection of a multitude of cultures and peoples.

M.Sc. (Biochemistry) / Tuberculosis (TB) is an infectious disease that worldwide, is more prevalent in Africans compared to Caucasians. TB also affects males to a greater extent than females. Genetic associations between VDR sequence variants and TB is often inconsistent across different populations. Epigenetic and environmental factors, as well as ethnicity may confound associations found between VDR and TB...

The World Health Organization (WHO) estimated that eight million new cases of tuberculosis (TB) occur every year and that one-third of the world’s population is infected with Mycobacterium tuberculosis (M. tuberculosis). With the increase in HIV/AIDS in the 1980’s, an increase in transmission of TB led to an increase in TB incidence. A study showed that South African adults (ages 15 to 49) will suffer 278 154 deaths between 2008 and 2017 if current control measures are continued. A M. tuberculosis strain that is resistant to isoniazid (INH) and rifampicin (RIF) used in the treatment of TB is known as a multi-drug resistant (MDR-TB) strain. In extensively drugresistant tuberculosis (XDR-TB) the M. tuberculosis strains are not only resistant to INH, RIF and any one of the fluoroquinolones but to at least one of the three injectable second-line drugs such as amikacin or kanamycin. Unfortunately, many people with XDR-TB will die because it is virtually impossible to formulate an effective treatment before the resistance pattern of the M. tuberculosis strain has been identified. Bacteriological culture is considered the diagnostic gold standard and can identify mycobacteria in over 80% of TB cases, with a specificity of over 98%. However, culturing the mycobacteria takes 4 to 6 weeks and makes diagnosis and treatment a prolonged process. In this study 60 patients suspected of TB disease, from the Anti-retroviral (ARV) clinic at the Tshwane District Hospital (TDH) were collected from October 2008 to April 2009. This study evaluated the use of the QuantiFERON-TB GOLD ELISA assay in a high burden setting. Tshwane District Hospital, South Africa. The sensitivity and specificity of the QFT assay in the clinic were 30% (9/30) and 63% (19/30) respectively when compared to the gold standard culture results. Analysis suggested that the sensitivity of the QuantiFERON assay is determined by a limiting patient CD4 value of between 150 and 200. Real-time PCR assays were used for rapid identification of Mycobacterium spp and to determine the presence of isoniazid and rifampicin resistant genes of M. tuberculosis strains. The real-time PCR assay identified 28% (17/60) M. tuberculosis, 2% (1/60) M. kansasii and 70% (42/60) of the isolates Mycobacterium spp negative. No M. avium were detected. The 17 M. tuberculosis positive specimens were further analysed for the presence of INH and RIF resistance genes. All 17 specimens had either no mutation or one or more mutations at the specific gene targets (rpo1, rpo2, katG and inhA). This study showed several possibilities for the use of both an immunological assay as well as molecular methods for the diagnosis of TB. This study suggested that in terms of routine diagnosis of TB in high HIV prevalence settings the QFT test should be used with caution. Realtime PCR for both detection and identification showed useful results and can be used together with culture results to improve turnaround times for TB diagnosis. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Medical Microbiology / unrestricted

Tuberculosis (TB) is the leading cause of death among HIV infected people. Mycobacterium tuberculosis (M. tuberculosis), the causative agent of TB, features a distinctive lipid-rich cell wall with mycolic acids (MA) the major component in the outer layer. Mycolic acids are á-alkyl â-hydroxy long chain fatty acids, which exist in a number of chemical subclasses depending on the presence of functional oxygenated and non-oxygenated groups in the meromycolate chain. In numerous studies the different MA subclasses have been shown to play different roles in antibody recognition, virulence and the ability to attract cholesterol. It was previously suggested that the oxygenated MA might be important for these properties. Except for the mycolic acid motif, little is known about the stereochemistry of the other chiral centres. The importance of the different functional groups, their position and stereochemistry, for immunological properties, are not yet clarified. This study set out to resolve the structureactivity relationships of mycolic acids from M. tuberculosis in terms of their antigenicity and the ability to attract cholesterol. To determine fine specificity of interaction of MA with antibodies, the subclasses of MA from M. tuberculosis were separated and the antigenicity of two was determined. TB+ and TB- patient sera recognised natural MA, alpha-MA and methoxy-MA. It was confirmed that the carboxylic acid group played a fundamental role in its recognition. Interestingly, cord factor (trehalose-6,6’-dimycolate) was recognised specifically by TB+ sera. This implies multiple epitopes in the MA structure, some of which are very specific for TB patients. A stereocontrolled diastereomer of cis-cyclopropane methoxy-MA was synthesized and along with other synthetic methoxy-, keto- and hydroxy-MAs, were tested for antibody recognition. One diastereomer, SS-SR-methoxy-MA, was recognised stronger by TB+ serum than the other, it also is the one that closest approximates the signal strength of antibody binding to natural MA by TB+ patient sera. While the others are not specifically recognised, this SS-SR-methoxy-MA may well represent one of the antigenically active components that occurs in natural MA and that elicits specific antibodies in TB patients. This thesis reports a stereocontrolled chemical synthesis of biologically active mycolic acids and shows that a single component of the mycolic acid mixture can be sufficient to elicit an immunological response. / Thesis (PHD)--University of Pretoria, 2008. / Biochemistry / unrestricted

Les nucléomodulines sont des protéines produites par des bactéries parasites intracellulaires et qui sont importées dans le noyau des cellules infectées pour y moduler l'expression génique et contribuer ainsi à la virulence de la bactéries. L'identification de nucléomodulines chez plusieurs espèces de bactéries pathogènes a fait émerger ce concept comme une stratégie supplémentaire utilisée par les parasites intracellulaires pour contourner les moyens de défense de l'hôte. Le but de cette thèse était d'identifier et d'analyser d'éventuelles nucléomodulines produites par l'agent étiologique de la tuberculose, la bactérie Mycobacterium tuberculosis (Mtb). Nous avons tout d'abord analysé le génome de Mtb, à la recherche de gènes dont les produits portent des séquences analogues aux séquences de localisation nucléaire des eucaryotes (NLS). Nous avons pu identifier deux gènes de Mtb, Rv0229c et Rv3876, qui codent des protéines sécrétées dans le milieu de culture et qui se localisent dans le noyau lorsqu'elles sont exprimées dans des cellules épithéliales ou dans des macrophages murins ou humains. Les NLS de ces deux protéines ont été identifiées et leur modification abolit la localisation nucléaire dans les cellules eucaryotes. Le gène Rv0229c est trouvé spécifiquement dans le génome des espèces pathogènes du complexe Mtb. Ce gène semble avoir été acquis récemment par l'ancêtre de Mtb, via un transfert génétique horizontal. Rv3876 est plus généralement distribué chez les mycobactéries, et appartient à une région génomique codant un système de sécrétion type VII, ESX1, essentiel pour la virulence de Mtb. Les travaux en cours visent à analyser la dynamique de ces deux protéines au cours de l'infection de macrophages ou de modèles animaux, et leur rôle en tant que modulateurs de l'expression génique des cellules infectées et dans la virulence de Mtb. / The nuclear targeting of bacterial proteins that modify host cell gene expression, the so-called nucleomodulins, has emerged as a novel mechanism contributing to virulence of several intracellular pathogens. The goal of this study was to identify nucleomodulins produced by Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), and to investigate their role upon infection of the host. We first performed a screening of Mtb genome in search of genes encoding proteins with putative eukaryotic-like nuclear localization signals (NLS). We identified two genes of Mtb, Rv0229c and Rv3876, encoding proteins that are secreted in the medium by Mtb and are localized into the nucleus when expressed in epithelial cells or in human or murine macrophages. The NLSs of these two proteins were identified and found to be essential for their nuclear localization. The gene Rv0229c, a putative RNase, is present only in pathogen species of the Mtb complex and seems to have been recently acquired by horizontal gene transfer (HGT). Rv3876 appears more widely distributed in mycobacteria, and belongs to a chromosomal region encoding proteins of the type VII secretion system ESX1, essential for virulence. Ongoing studies are currently investigating the dynamics of these proteins upon infection of host cells, and their putative role in the modulation of host cell gene expression and Mtb virulence.

Mycobacterium tuberculosis (M. tuberculosis) , the etiological agent of tuberculosis, is an intracellular bacterium which persists within macrophages. Successful control of tuberculosis depends on T-cell-mediated immunity. Immune protection involves the development of a Th1 response characterised by the secretion of cytokines such as IL-12, IFN-γ and TNF-α. The progression towards disease in humans and mice is often associated with a Th2 response characterised by the secretion of cytokines such as I L-4 and I L-10. Mycolic acids, the major cell wall lipid of M. tuberculosis, were previously shown to have a marginally protective effect on the development of disease in Balb/c mice when administered intravenously at an optimal dose of 25 µg one week before intravenous M. tuberculosis infection. Here it is shown that the protective effect is highly significant when infection is done intranasally. The protective effect of 25 µg mycolic acids against tuberculosis could not be explained by induction of a longer lasting Th1 response in Balb/c mice. This was determined by using semi-quantitative RT-PCR on the mRNA of cytokines characteristic of the different immune responses. It was observed that maximum sensitivity was obtained at the lowest possible PCR cycle and template concentrations for the samples. Mycolic acids were the first non-protein antigens shown to induce an immune response after presentation on CD1 membrane proteins. Balb/c mice predominantly generate a Th1 response during the first 3 - 4 weeks of M. tuberculosis infection, whereas they generate a Th2 response in the following weeks. Even though the protective effect of 25 µg mycolic acids could not be associated with a prolonged Th1 immune response in infected mice, it did induce IL-12 and IL-10 mRNA in uninfected mice. These cytokines are primarily. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2005. / Biochemistry / unrestricted

Tuberculosis, caused by the intracellular pathogen Mycobacterium tuberculosis, is one of the most prevalent infectious diseases in our world today. In order to survive within the host the bacteria need to sense and respond to changes in the environment; however, signal transduction in this bacterium is poorly understood. PknB is a serine/threonine kinase essential for the in vitro survival of M. tuberculosis and therefore a potential drug target against the bacteria. It is the goal of the current study to elucidate downstream substrates of PknB. We have found that PknB shares in vitro substrates with another serine/threonine kinase, PknH, implying the potential complexity of the signaling pathways in the bacteria. We have also provided the first description of the coupling between serine/threonine kinases PknB and PknH with a two-component system response regulator DevR, and further proposed Ser/Thr phosphorylation as the negative regulator of DevR transcription activator activity based on LC-MS/MS analysis. Finally, we have identified a previously unknown phosphoprotein glyceraldehyde 3-phosphate dehydrogenase encoded by the ORF Rv1436, which demonstrates autophosphorylation activity and which phosphorylation is independent of PknB. Overall, the current study has contributed to advance our understanding of the signal transduction pathways and phosphoproteome in Mycobacterium tuberculosis. / Medicine, Faculty of / Medicine, Department of / Experimental Medicine, Division of / Graduate

Mycobacterium tuberculosis (Mtb) causes tuberculosis (TB) and poses a global threat to human health. A third of the world’s population is infected with Mtb. Multi-drug resistant and extensively drug resistant Mtb strains are widespread and development of new drugs is urgently needed to treat drug resistant TB. This thesis focuses on the Mtb cytochrome P450 (P450) enzymes CYP126A1 and CYP143A1. P450s are heme-binding enzymes that catalyse activation of molecular oxygen and the oxidation of substrates bound close to the heme. CYP126A1 and CYP143A1 are “orphans” in terms of their functional characterization, but potential drug targets in view of ability of azole-based P450 inhibitors to inhibit growth and viability of Mtb. The CYP126A1 and CYP143A1 genes were cloned and expressed in Escherichia coli. Expression conditions and strains were optimised to maximise soluble protein production and methods were developed to purify the P450s using affinity, ion exchange and size exclusion chromatography. Both P450s were shown to bind heme b, and heme was shown to be axially coordinated by a cysteine thiolate and a water molecule in both cases using UV-visible and electron paramagnetic resonance (EPR) spectroscopy. Both P450s bound carbon monoxide (CO) in their reduced forms to produce heme Fe2+-CO complexes with absorption maxima at ~450 nm – characteristic of P450s. CYP126A1 and CYP143A1 bound avidly to a range of inhibitors, including several azole drugs. As examples, binding constant (Kd) values of 13.8 µM and 21.9 µM were determined for clotrimazole and econazole with CYP143A1; while ketoconazole bound CYP126A1 with a Kd of 0.20 µM. Each of these drugs is very effective in inhibiting Mtb growth. EPR confirmed inhibitory coordination of both P450s by azole drug nitrogen atoms; though indirect coordination via a retained axial water ligand may also occur in some cases. Extinction coefficients were determined as έ420 = 125 mM-1 cm-1 (CYP126A1) and έ415 = 105 mM-1 cm-1 (CYP143A1). CYP126A1’s heme iron redox potential was shown to be unusually positive (E°’ = -80 mV). Light scattering studies showed CYP126A1 to be a monodisperse, monomeric protein. CYP143A1 is also mainly a monomer, but with a small proportion of an oligomeric form. Despite its polydispersity, CYP143A1 was crystallized and its structure solved by X-ray diffraction to a resolution of 1.9 Å, using molecular replacement with the Mtb P450 CYP142A1. A limited compound screen of typical P450 substrates failed to provide “hits” to identify CYP143A1 substrate selectivity, but the presence of polyethylene glycol in the CYP143A1 active site in crystals suggests fatty acids as potential substrates. CYP126A1 was crystallized for studies to identify binding modes of small molecules (“fragments”) identified to interact with CYP126A1 by NMR. Crystal structures of CYP126A1 in complex with two such fragments (NMR401 and NMR343) were determined to ~2.0 Å resolution in ongoing research to build Mtb P450 isoform-specific inhibitors. Compounds identified as CYP126A1 substrates/inhibitors identified by high-throughput screening were validated by UV-visible titrations with the P450, and binding modes and affinity established. In conclusion, this thesis provides novel insights into the biochemical, biophysical and structural properties of two novel Mtb P450s that are potential targets for new anti-TB drugs.

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Bioquímica, Florianópolis, 2015. / Made available in DSpace on 2016-05-24T17:52:39Z (GMT). No. of bitstreams: 1 334243.pdf: 5585985 bytes, checksum: 4f3d8bd503e7a8f2e8284a04905635ec (MD5) Previous issue date: 2015 / Proteínas tirosina fosfatases (PTP) têm um importante papel na transdução de sinal e no controle de diversas funções celulares. Bactérias patogênicas como as do gênero Yersinia e do complexo Mycobacterium tuberculosis (Mtb), utilizam suas PTP para subverter as células de defesa do hospedeiro. As bactérias patogênicas do gênero Yersinia possuem em comum a produção de uma PTP chamada YopH que modula a resposta inflamatória do hospedeiro à bactéria através de processos que envolvem a inibição da fagocitose, quebra de adesões focais e subversão da função dos linfócitos B e T prevenindo a resposta imune adaptativa. As doenças humanas causadas pelas espécies patogênicas de Yersinia variam desde síndromes gastrointestinais à peste bubônica, sendo esta última uma doença grave que ainda não foi erradicada e é associada a milhares de mortes no passado. O Mtb causa a tuberculose, doença que afeta principalmente o trato respiratório. Segundo dados da Organização Mundial da Saúde, a tuberculose foi responsável por 1,5 milhões de mortes somente no ano de 2013. Durantes a invasão das células de defesa, o Mtb produz duas PTP, a PtpA e a PtpB. Estas fosfatases, assim como a YopH, tem por função burlar o mecanismo de defesa do hospedeiro. A PtpA é responsável por modular a apoptose celular e impedir a acidificação do fagossomo e a fusão deste com o lisossomo. Já a PtpB, impede a produção de IL-6 e previne a morte do macrófago pela ativação da via de sinalização de Akt e bloqueio da atividade da caspase-3. A busca de inibidores da YopH de Yersinia spp. e das fosfatases do Mtb é de grande interesse para a produção de possíveis fármacos que poderiam ser utilizados no tratamento das doenças provocadas por estas bactérias. No presente trabalho, uma biblioteca de 398 compostos foi triada com o objetivo de identificar novos inibidores da YopH. Dentre os inibidores encontrados, 22 apresentaram valores de IC50 inferiores a 10 µM, sendo que 3 estão na faixa de nanomolar (o que os coloca entre os melhores inibidores descritos para esta fosfatase até o momento). Foram encontrados tanto inibidores competitivos (12 compostos) como não competitivos (6 compostos) da YopH e cinco compostos (delfinidina, AAA e os três complexos de vanádio) apresentaram valores de Ki na faixa de nanomolar. Avaliou-se também a citotoxicidade em células THP-1 e HepG2 além da atividade antitubercular de seis inibidores das fosfatases de Mtb (PtpA e PtpB) previamente relatados por nosso laboratório em 2012. Identificou-se dois compostos que não são citotóxicos (compostos 43 e 95) e dois compostos que apresentaram atividade em ensaios de infecção intracelular (compostos 95 e 96). De acordo com todos os resultados obtidos no presente trabalho, identificamos novas chalconas como eficientes inibidores da YopH além de 3 complexos de vanádio com uma marcante inibição em escala nanomolar. Quanto aos inibidores da PtpA e PtpB, o composto 95 mostrou-se não citotóxico e com atividade nos ensaios de infecção intracelular. Este composto poderia ser utilizado como molde na busca de outros compostos mais ativos ajudando assim no desenvolvimento de novas terapias contra o Mycobacterium tuberculosis.<br> / Abstract : Protein tyrosine phosphatases (PTP) have an important role in signal transduction and in the control of many cell functions. Pathogenic bacteria from Yersinia genus and Mycobacterium tuberculosis (Mtb) complex, utilize their PTP to subvert host?s defense cells. Pathogenic bacteria from Yersinia genus have in common the production of a PTP named YopH, this enzyme modules the host inflammatory response against the bacteria through processes that evolves the phagocytosis inhibition, focal adhesion disruption and impairing the function of B and T lymphocytes preventing the adaptive immune response. Diseases caused by pathogenic species of Yersinia range from gastrointestinal syndromes to bubonic plague. Bubonic plague is a not eradicated disease that is associated with thousands of deaths in the past. Mtb causes tuberculosis, a disease that affects mainly the respiratory tract. According to World Health Organization data, only in 2013 tuberculosis caused 1.5 million deaths. During the defense cell invasion, Mtb produces two PTP, PtpA and PtpB. These phosphatases act like YopH, they help the bacteria to evade the host defense mechanism. PtpA modulates the cellular aptotosis and it also impairs the phagosome acidification and its fusion with lysosome. PtpB prevents the production of IL-6 and macrophage death by activation Akt signaling pathway and by blocking caspase 3 activity. The search for inhibitors of YopH from Yersinia and Mtb phosphatases is of great interest for the production of drugs that could be used in the treatment of the diseases caused by these bacteria. In this work, an in-house library of 398 compounds was screened with the objective to search new YopH inhibitors. Out of the inhibitors found, 22 presented IC50 values below 10 µM, three of those in nanomolar range (this characteristic put these three compounds between the best described inhibitors for this phosphatase). We found competitive inhibitors (12 compounds) and non-competitive inhibitors (6 compounds) for YopH and five compounds (Delphinidin, AAA and three vanadium complexes) presented Ki values in nanomolar range. Cytotoxicity assays were made with two human cell lines THP-1 and HepG2 we also assayed the antitubercular activity of six inhibitors of Mtb PTP. The inhibitory activity against PtpA and PtpB of these six compounds was previously described in 2012 by our lab. The cytotoxicity and antitubercular assays resulted in two non-cytotoxic compounds (compound 43 and 95) and two compounds that are activity in intracell infection assays (compounds 95 and 96). In this present work we show new chalcones as eficient inhibitors of YopH, we also identified 3 vanadium complex with remarkable inhibition in nanomolar scale. According to the results obtained to PtpA and PtpB inhibitors, we identified the compound 95 which is no cytotoxic and has activity in intracell assays. This compoud could be used for the design of new compound with improved activity helping in the development of new therapies against Mycobacterium tuberculosis.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2015-11-16T16:31:34Z No. of bitstreams: 1 texto completo.pdf: 1375656 bytes, checksum: 6b33bdf6230c90a2e18e46517b201f11 (MD5) / Made available in DSpace on 2015-11-16T16:31:34Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1375656 bytes, checksum: 6b33bdf6230c90a2e18e46517b201f11 (MD5) Previous issue date: 2015-06-03 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Minas Gerais é o principal produtor de leite de cabra na região Sudeste e o terceiro principal estado do país nessa atividade. A paratuberculose é uma enfermidade intestinal crônica, causada por Mycobacterium avium subsp. paratuberculosis (Map), que acomete principalmente ruminantes e é transmitida pela ingestão de alimentos ou água contaminados por fezes de animais acometidos. O objetivo do trabalho foi identificar e caracterizar Mycobacterium avium subsp. paratuberculosis em fazendas de caprinos leiteiros da Zona da Mata de Minas Gerais. Foram estudadas dez propriedades, caracterizadas através da aplicação de um questionário com a pessoa responsável pelo manejo. Foram coletadas amostras de fezes e de leite dos 467 animais amostrados, que foram inoculadas em meio HEYM. As amostras de leite e as colônias suspeitas foram submetidas à PCR e aquelas consideradas positivas foram sequenciadas. Onze (2,36%) animais foram considerados positivos para a presença de Map, em quatro (40%) propriedades. Através das técnicas utilizadas, concluiu-se que Map está presente nas propriedades de caprinos leiteiros da Zona da Mata de Minas Gerais. Com esse estudo, foi possível analisar e caracterizar os diferentes modos de produção de leite de cabra empregados na Zona da Mata. Os produtores têm relativa instrução, mas ainda convivem com a baixa produtividade e o baixo rendimento da produção, o que leva a maioria a necessitar de outras fontes de renda. O incentivo governamental exerce papel fundamental na mudança do cenário atual da caprinocultura leiteira dessa mesorregião e, levando à estruturação da cadeia produtiva, alcança melhores resultados de produção e geração de emprego e renda no meio rural. / The participation of dairy goat in the Brazilian agricultural scenario has increased and has consolidated as profitable. Minas Gerais is the main producer of goat's milk in the Southeast and the third largest state in the country in this activity. The paratuberculosis is a chronic intestinal illness caused by Mycobacterium avium subsp. paratuberculosis (Map), which mainly affects ruminants and is transmitted by ingesting food or water contaminated by feces of affected animals. The objective was to identify and characterize Mycobacterium avium subsp. paratuberculosis in dairy goat farms in the Zona da Mata of Minas Gerais. Ten properties were studied, characterized by applying a questionnaire to the person responsible for the handling. Samples of feces and milk were collected of 467 animals studied, and inoculated in HEYM medium. Samples of milk and suspected colonies were submitted to PCR, and the samples considered positive were sequenced. Eleven (2.36%) animals were considered positive for the presence of Map, in four (40%) properties. Through the techniques used, it was concluded that Map is present in dairy goats properties of Zona da Mata of Minas Gerais. With this study, we analyzed and characterized different types of goat production used in the Zona da Mata. Producers have relative education, but still living with low productivity and low income of their production, which leads most in need of other sources of income. The government incentive plays a fundamental role in changing the current scenario of dairy goat at this region and, leading to the structuring of the production chain, achieves better results of production and generation of employment and income in rural areas.