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espanolLa Paratuberculosis Bovina (PTB) o Enfermedad de Johne, es una infeccion del tracto gastrointestinal causada por Mycobacterium avium, subespecie paratuberculosis (Map), que se caracteriza por generar enteritis granulomatosa cronica y linfadenitis en rumiantes. La preocupacion mas relevante en relacion con la importancia de la PTB es su posible vinculo con la Enfermedad de Crohn (EC) en humanos, sin embargo, esta asociacion aun esta bajo investigacion. Se determino la seroprevalencia de PTB en el municipio de Sogamoso (Boyaca), donde se recolectaron 604 muestras de sangre, cuyo suero fue procesado mediante la tecnica de ELISA indirecta con el kit comercial PARACHEK® 2 KIT (Prionics, Suiza). La seroprevalencia fue de 10,9% (66/604), donde el grupo etario de 2 a 3 anos y la raza Jersey fueron los de mayor seroprevalencia. Se encontro asociacion estadistica significativa (p≤0,05) entre la edad de los individuos evaluados y el suministro de concentrado. La seroprevalencia encontrada indica que se esta produciendo una transmision activa de la enfermedad y que las medidas de control disponibles no estan siendo llevadas a cabo o no son lo suficientemente efectivas. EnglishBovine Paratuberculosis (BPT), or Johne's Disease, is an infection of the gastrointestinal tract caused by Mycobacterium avium, subspecies paratuberculosis (Map), which is characterized by chronic granulomatous enteritis and lymphadenitis in ruminants. The most relevant concern regarding the importance of BPT is its possible link to Crohn's disease (CD) in humans, however this association is still under investigation. The seroprevalence of BPT was determined in the municipality of Sogamoso (Boyaca), where 604 blood samples were collected, their serum was processed by the indirect ELISA technique with the commercial PARACHEK® 2 KIT (Prionics, Switzerland), following the manufacturer's instructions. The seroprevalence was 10,9% (66/604), with the 2 to 3 years age group and the Jersey breed having the highest seroprevalence. A significant statistical association was found (p≤0,05) with the age of the individuals tested and the supply of concentrate. The seroprevalence found indicates that active transmission of the disease is taking place, and that the available control measures are not being carried out or are not effective enough. portuguesA Paratuberculose Bovina (PTB) ou Doenca de Johne e uma infeccao do trato gastrointestinal causada pela Mycobacterium avium subespecie paratuberculosis (Map), caracterizada por gerar enterite granulomatosa cronica e linfadenite em ruminantes. A preocupacao mais relevante em relacao a importância do PTB e seu possivel vinculo com a Doenca de Crohn (DC) em seres humanos, no entanto, essa associacao ainda esta sob investigacao. A soroprevalencia do PTB foi determinada no municipio de Sogamoso (Boyaca), onde foram coletadas 604 amostras de sangue, cujo soro foi processado pela tecnica ELISA indireta com o kit comercial PARACHEK® 2 KIT (Prionics, Suica). A soroprevalencia foi de 10,9% (66/604), onde a faixa etaria de 2 a 3 anos e a raca Jersey foram as que apresentaram maior soroprevalencia. Foi encontrada associacao estatisticamente significante (p≤0,05) com a idade dos individuos avaliados e o suprimento de concentrado. A soroprevalencia encontrada indica que a transmissao ativa da doenca esta ocorrendo e que as medidas de controle disponiveis nao estao sendo realizadas ou nao sao eficazes o suficiente.

Mycobacterium avium subsp. paratuberculosis (Map) is the underlying pathogen causing bovine paratuberculosis (PTB), an enteric granulomatous disease that mainly affects ruminants and for which an effective treatment is needed. Macrophages are the primary target cells for Map, which survives and replicates intracellularly by inhibiting phagosome maturation. Neutrophils are present at disease sites during the early stages of the infection, but seem to be absent in the late stage, in contrast to healthy tissue. Although neutrophil activity has been reported to be impaired following Map infection, their role in PTB pathogenesis has not been fully defined. Neutrophils are capable of releasing extracellular traps consisting of extruded DNA and proteins that immobilize and kill microorganisms, but this mechanism has not been evaluated against Map. Our main objective was to study the interaction of neutrophils with macrophages during an in vitro mycobacterial infection. For this purpose, neutrophils and macrophages from the same animal were cultured alone or together in the presence of Map or Mycobacterium bovis Bacillus-Calmette-Guerin (BCG). Extracellular trap release, mycobacteria killing as well as IL-1 beta and IL-8 release were assessed. Neutrophils released extracellular traps against mycobacteria when cultured alone and in the presence of macrophages without direct cell contact, but resulted inhibited in direct contact. Macrophages were extremely efficient at killing BCG, but ineffective at killing Map. In contrast, neutrophils showed similar killing rates for both mycobacteria. Co-cultures infected with Map showed the expected killing effect of combining both cell types, whereas co-cultures infected with BCG showed a potentiated killing effect beyond the expected one, indicating a potential synergistic cooperation. In both cases, IL-1 beta and IL-8 levels were lower in co-cultures, suggestive of a reduced inflammatory reaction. These data indicate that cooperation of both cell types can be beneficial in terms of decreasing the inflammatory reaction while the effective elimination of Map can be compromised. These results suggest that neutrophils are effective at Map killing and can exert protective mechanisms against Map that seem to fail during PTB disease after the arrival of macrophages at the infection site Funding was provided by Spanish central government and Basque research project PROBAK (RTA 2017-00089-00-00) and by the Departamento de Economia e Infraestructuras of the Basque Government. IL-A held a predoctoral grant from Departamento de Economia e Infraestructuras of the Basque Government (2017) and was granted an EMBO short-term fellowship (8407) and a FEMS research and training grant (FEMS-GO-2019-507). The funders had no role in the study design, data collection and interpretation, or the decision to submit the work for publication

The aim of this study was to describe the genetic diversity of Mycobacterium avium subsp. paratuberculosis (MAP) obtained from individual cows in Korea. Twelve MAP-positive fecal DNA samples and 19 MAP isolates were obtained from 10 cattle herds located in 5 provinces in Korea. In addition, 5 MAP isolates obtained from the Czech Republic and Slovakia and 3 isolates from Australia were genotyped for comparison with the domestic isolates. The most prevalent strains in Korea were of the "bison-type" genotype (23 of 31 fecal DNA/isolates) and were distributed nationwide. The remaining MAP isolates (8) and all of the foreign isolates were identified as "cattle-type". The bison-type strains which were discriminated only as INMV 68 in variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR) typing. Multilocus short sequence repeat (MLSSR) typing differentiated the bison-type strains into 3 different subtypes. The cattle-type strains were divided into 3 subtypes by MIRU-VNTR and 8 subtypes by MLSSR. The allelic diversities in the MIRU-VNTR and MLSSR results were calculated as 0.567 and 0.866, respectively. These results suggest that MIRU-VNTR typing cannot provide a sufficient description of the epidemiological situation of MAP. Therefore, an alternative method, such as MLSSR, is needed for typing of MAP strains to elucidate the molecular epidemiology of MAP infections. Overall, this study is the first epidemiological survey report in Korea using both MIRU-VNTR and MLSSR typing methods, and it has provided basic data necessary to elucidate the characteristics of MAP infections in Korea.

Paratuberculosis is a chronic disease of ruminants caused by Mycobacterium avium subsp. Paratuberculosis (MAP). Since isolation of MAP type I (S) is rarely reported in Italy, our research was aimed at isolating, by an inexpensive liquid culture manual method, this type of MAP isolates. At first, we used an ELISA to point out to serologically positive samples from five flocks. Secondly, we used a fecal direct IS900-qPCR on the ELISA positive samples, in order to detect shedder animals. Feces from IS900-qPCR positive samples were inoculated in solid and liquid culture media. IS900-qPCR was further used to test the growth of MAP isolates in liquid medium, which were further confirmed by f57-qPCR and submitted to typing by specific PCR in order to identify the MAP type. Twenty-eight samples (24 fecal and four tissutal samples) were processed by culture methods, resulting in the isolation of six type I MAP field isolates. Notably, no isolates were recovered by solid media, underlining the utility of this liquid method. Few data about this type of MAP are currently available in Italy, and further analyses should be carried out in order to study the origin and epidemiology of type I strains circulating in Italy.

In the last decade there was a significant increase dairy goat participation in the world and Brazilian agricultural scenario. Minas Gerais state is the third largest producer of goat milk in Brazil. Paratuberculosis is a chronic intestinal disease that mostly affects ruminants and can become a public health problem due to the possible association with Crohn's disease. It is transmitted by ingesting Mycobacterium avium subsp. paratuberculosis (MAP) contaminated food or water. In recent years, with the development of molecular techniques, the disease has been identified with greater precision and more quickly. MAP strains (S-Sheep, Cattle-C and B-Bison) have also been typed. The detection of a circulating MAP strain in a herd is important to develop epidemiological studies and thus establish better strategies to control paratuberculosis. This study aimed to identify and type MAP in dairy goat farms in the Zona da Mata, the main producing region of Minas Gerais state, Brazil. Feces and milk samples of 467 animals were collected, processed, inoculated in Herrold's Egg Yolk Agar (HEYM) and submitted to PCR and REA techniques. Eleven (2.36%) animals were positive for the presence of MAP in four properties and the isolates were characterized as type C strain. It was concluded that MAP is present in dairy goats from properties in Zona da Mata, MG and that strain type C circulates in the area. This is the first report of MAP typing isolated from dairy goat in Brazil.

Paratuberculosis, caused byMycobacterium aviumsubsp.paratuberculosis(MAP), is a chronic incurable infection of intestinal tract of animals. The study took place in 2012, on 491 Korean black goats, older than 2 years, from goat herds located in Southern region, Korea. The animals were sampled and tested for paratuberculosis. Enzyme-linked immunosorbent assay and microbiological culture were used to investigate MAP infection. Among the 491 goats from 100 herds screened, 4 (0.8%) and 3 (0.6%) goats were defined positive for MAP by ELISA and faecal culture, respectively. Isolated colonies were confirmed as MAP by IS900-PCR, and genotyped by IS1311 PCR-REA assays. The results revealed MAP infection at a low prevalence rate with "cattle type" and "bison type" genotypes. &nbsp, La paratuberculosis, causada porMycobacterium aviumsubsp.paratuberculosis(MAP), es una infección crónica e incurable del tracto intestinal de los animales. El estudio se realizó en 2012, usando muestras procedentes de 491 cabras negras coreanas, menores de 2 años, procedentes de un rebaño caprino de la región Sur de Corea. Los animales se evaluaron para detectar presencia de paratuberculosis. Los métodos utilizados para investigar las infecciones por MAP fueron ensayo por inmunoabsorción ligado a enzimas y cultivos microbiológicos. De las 491 cabras de 100 rebaños seleccionados, 4 (0,8%) y 3 (0,6%) dieron resultados positivos para MAP en la prueba de ELISA y el estudio microbiológico de coprocultivo, respectivamente. Las colonias aisladas fueron confirmadas como MAP por IS900-PCR y su tipificación se realizó por medio del ensayo de IS1311 PCR-REA. Los resultados revelaron una baja tasa de prevalencia de infecciones por MAP de cepas de "tipo bovino" y "tipo bisonte". &nbsp

International audience; AbstractCurrent Johne’s disease control programs primarily focus on decreasing transmission of Mycobacterium avium subsp. paratuberculosis (MAP) from infectious adult cows to susceptible calves. However, potential transmission between calves is largely overlooked. The objective was to determine the extent of MAP infection in calves contact-exposed to infectious penmates. Thirty-two newborn Holstein–Friesian calves were grouped into 7 experimental groups of 4, consisting of 2 inoculated (IN) calves, and 2 contact-exposed (CE) calves, and 1 control pen with 4 non-exposed calves. Calves were group housed for 3 months, with fecal samples were collected 3 times per week, blood and environmental samples weekly, and tissue samples at the end of the trial. The IN calves exited the trial after 3 months of group housing, whereas CE calves were individually housed for an additional 3 months before euthanasia. Control calves were group-housed for the entire trial. All CE and IN calves had MAP-positive fecal samples during the period of group housing; however, fecal shedding had ceased at time of individual housing. All IN calves had MAP-positive tissue samples at necropsy, and 7 (50%) of the CE had positive tissue samples. None of the calves had a humoral immune response, whereas INF-γ responses were detected in all IN calves and 5 (36%) CE calves. In conclusion, new MAP infections occurred due to exposure of infectious penmates to contact calves. Therefore, calf-to-calf transmission is a potential route of uncontrolled transmission on cattle farms.

Mycobacterium avium subsp. paratuberculosis (MAP) is a well-established etiological agent of Johne’s disease in animals. In humans, similar clinical condition, first described by Crohn as regional ileitis in 1932, now known as Crohn’s diseases (CD), has also been associated with this mycobacterial species. However, there are two schools of thoughts, one favoring MAP as its etiological agent while the second considers it as an immune-inflammatory condition triggered by an external factor. Onset of CD requires a series of events including predisposition of certain inherited genetic traits, associated environmental stimuli, and immune-inflammatory response. A combination of these factors probably leads to this disease. Recently, some human genes have also been identified which regulate ability to respond appropriately to the external factors. Added to these factors are concerns about the selection of clinical specimens and poor adherence to laboratory quality controls. The literature is full of contradictory findings, but there a lack of uniformity in the materials and methods used by many of these researchers. In this review, we provide our perspective under above circumstances and give our point of view which may open a platform for debate regarding the MAP as the etiological agent of human CD.

11 páginas, 3 tablas, 3 figuras, Rabbits are susceptible to infection by different species of the genus Mycobacterium. Particularly, development of specific lesions and isolation of Mycobacterium avium subsp. avium and Mycobacterium avium subsp. paratuberculosis, both subspecies of the M. avium complex, has been reported in wildlife conditions. Although, rabbit meat production worldwide is 200 million tons per year, microbiological data on this source of meat is lacking and more specifically reports of mycobacterial presence in industrially reared rabbit for human consumption have not been published. To this end, we sought mycobacteria by microbiological and histopathological methods paying special attention to Mycobacterium avium subsp. paratuberculosis in rabbits from commercial rabbitries from the North East of Spain., This study was supported by grants (AGL2012-39818-CO2-02) and (INIA, RTA2010-00022) from the Spanish Ministry of Economy and Competitiveness (MINECO) and the Spanish National Institute for Agricultural and Food Research and Technology, respectively. Rakel Arrazuria held a pre doctoral fellowship (BFI-2012-237) from the Basque Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Summary Background: paratuberculosis (PTB) is clinically characterized by diarrhea and progressive weight loss in ruminants, and causes economic losses due to decreased milk production, premature animal disposal, and increased veterinary treatment costs. The presence of PTB has been increasing in milk producing bovine farms in Mexico, yet epidemiology data from specific farms remains scarce. Objective: to determine the proportion of cows positive for Mycobacterium avium subsp. paratuberculosis (Map) among culled cows. Methods: in the present study, 40 culled cows from 25 farms located at the complejo agropecuario industrial de Tizayuca (CAITSA) in Hidalgo (Mexico) were evaluated for PTB presence by histopathological and microbiological studies. Tissue and rectal scraping samples were taken from all cows, and studied for presence of histopathology PTB-compatible lesions. Samples were processed for Map isolation on selective agar culture media; typical Map colonies were confirmed by polymerase chain reaction (PCR). Results: potential PTB infection was found in 25% (10/40) of the animals evaluated by histopathology and acid-fast bacilli (AFB) staining, but only 7.5% (3/40) were positive for type 2 Map (C cattle strain) by PCR. Conclusions: the prevalence of PTB in cattle farms at CAITSA was confirmed, which may be valuable epidemiological information in Mexico . Keywords: cull cattle, Mycobacterium avium subsp. paratuberculosis, paratuberculosis diagnosis, ruminant farms. Resumen Antecedentes: la paratuberculosis (PTB) se caracteriza clinicamente por diarrea y perdida de peso progresiva en rumiantes y causa perdidas economicas por la disminucion de la produccion de leche, eliminacion prematura de animales y el aumento de los costos de tratamiento veterinario. La PTB se ha incrementado en las granjas productoras de leche de bovinos en Mexico, pero se carece de informacion epidemiologica especifica de granjas locales. Objetivo: determinar el porcentaje de infeccion por Mycobacterium avium subsp. paratuberculosis (Map) entre las vacas de descarte. Metodos: en este estudio fueron evaluadas 40 vacas de descarte o de 25 granjas del complejo agropecuario industrial de Tizayuca (CAITSA), en el estado de Hidalgo (Mexico), donde se evaluo la presencia de la PTB mediante estudios histopatologicos y microbiologicos. Se tomaron muestras de tejido y raspado rectal de todos los animales buscando lesiones compatibles con PTB. Las muestras fueron procesadas para el aislamiento de Map en medios de cultivo de agar selectivo, y las colonias identificadas como tipicas fueron confirmadas por la prueba de reaccion en cadena de la polimerasa (PCR). Resultados: en este estudio se observo positividad para PTB por histopatologia y presencia de bacilos acido alcohol resistentes (AFB) en el 25% de los animales (10/40), pero solo en el 7,5% (3/40) de las vacas de descarte se confirmo la cepa tipo 2 (cepa C) de Map mediante PCR. Conclusiones : se confirma la prevalencia de PTB en las vacas del CAITSA, lo cual podria tener valor como informacion epidemiologica en Mexico. Palabras clave: bovinos de descarte, diagnostico de paratuberculosis, granjas de rumiantes, Mycobacterium avium subsp. paratuberculosis. Resumo Antecedentes: a paratuberculose (PTB) em vacas leiteiras caracteriza-se clinicamente pela presenca de diarreia e perda de peso progressiva as quais provocam perdas economicas pela reducao da producao de leite, abate prematuro dos animais e aumento dos custos de tratamento veterinario. A PTB aumentou-se em fazendas leiteiras no Mexico, mas ainda nao ha informacoes epidemiologicas especificas das fazendas locais. Objetivo: determinar a percentagem de infeccao por Mycobacterium avium subsp. paratuberculosis (Map) em vacas de descarte. Metodos: se avaliaram por estudos histopatologicos e microbiologicos 40 vacas de descarte de 25 fazendas do complexo agropecuario industrial de Tizayuca (CAITSA), no estado de Hidalgo (Mexico). Tomaram-se amostras de tecido e raspado anal de todos os animais procurando por lesoes compativeis com PTB. As amostras foram processadas para isolamento de Map em meios de agar seletivos e as colonias classificadas como tipicas foram confirmadas pelo teste da reacao em cadeia da enzima polimerase (PCR). Resultados: observou-se positividade para PTB pelos estudos histopatologicos e microbiologicos e a presenca de bacilos acido alcool resistente (AFB) no 25% dos animais (10/40), mas so no 7,5% (3/40) confirmaram-se a cepa tipo II (cepa C) de Map por PCR. Conclusoes: confirma-se a presenca de PTB em vacas do complexo CAITSA, o qual poderia ter valor epidemiologico no Mexico. Palavras chave : bovinos de descarte, diagnostico de paratuberculose, granjas de ruminantes, Mycobacterium avium subsp. paratuberculosis.

Mycobaterium avium subsp. paratuberculosis (MAP) tem atraído o interesse de pesquisadores devido às semelhanças entre a paratuberculose e a doença de Crohn (CD). Este estudo objetivou avaliar a frequência de MAP por meio de cultura, histologia e reação da polimerase em cadeia (PCR), em biópsias intestinais de pacientes brasileiros com CD. PCR quantitativa em tempo real (qRT-PCR) foi realizada nas amostras positivas. Estudo transversal analítico com grupo controle realizado em duas universidades federais. Amostras frescas foram coletadas de 25 pacientes; cinco com CD, oito com colite ulcerativa (UC) e 12 controles sem doença inflamatória intestinal (nIBD). Também foram coletadas 149 amostras fixadas em parafina (FFPE): 44 CD, 49 UC e 56 nIBD. Nenhuma das amostras frescas foi positiva para MAP. Cinco amostras FFPE (uma CD, duas UC e duas nIBD) e três amostras frescas (uma de cada grupo) foram positivas por IS900-PCR. qRT-PCR foi realizada nessas oito amostras. Nas amostras FFPE, havia 192,12 cópias/μl no grupo CD, 72,28 cópias/μl no UC e 81,43 cópias/μl no nIBD. Nas amostras frescas, havia 432,99 cópias/μl, 167,92 cópias/μl e 249,73 cópias/μl nos grupos CD, UC e nIBD, respectivamente. A maior carga bacteriana foi encontrada no grupo CD. Este estudo não fornece evidências do papel de MAP na etiologia da CD, embora DNA de MAP tenha sido detectado em pacientes dos três grupos. Este é o primeiro relato da presença de MAP em biópsias intestinais humanas no Brasil. Mycobacterium avium subsp. paratuberculosis (MAP) has attracted the interest of researchers because of similarities between paratuberculosis and Crohn's disease (CD). The aim of this study was to evaluate the frequency of MAP through cultures, histology and polymerase chain reaction (PCR) on intestinal biopsies from Brazilian CD patients. Quantitative real time PCR (qRT-PCR) was performed on positive samples. Fresh samples were collected from 25 patients; five with CD, eight with ulcerative colitis (UC) and 12 controls with non-inflammatory bowel disease (nIBD). Formalin-fixed paraffin-embedded (FFPE) samples from 143 patients were also collected: 44 CD, 49 UC and 56 nIBD. None of the fresh samples was positive for MAP. Five FFPE samples (one CD, two UC and two nIBD) and three fresh samples (one in each group) were positive through IS900-PCR. qRT-PCR was performed on these eight samples. Among the FFPE samples, there were 192.12 copies/μl in the CD group, 72.28 copies/μl in UC and 81.43 copies/μl in nIBD. Among the fresh samples, there were 432.99 copies/μl, 167.92 copies/μl and 249.73 copies/μl in the CD, UC and nIBD groups, respectively. The highest bacterial load was in the CD group. 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.

Within-herd transmission of pathogens occurs either by direct or by indirect contact between susceptible and infected animals. In dairy herds that are structured into groups, the way in which animals encounter each other and share an environment can affect pathogen transmission. Dairy cattle are heterogeneous in terms of susceptibility and infectivity with respect to Mycobacterium avium subspecies paratuberculosis (Map) transmission. It is mainly young animals that are susceptible and adults that are infectious. Both vertical and horizontal transmission through the ingestion of Map shed into the environment by adults and transiently infected calves can occur. Our objective was to assess the effect of contact structure on Map transmission in persistently infected dairy herds and to examine the effect of isolating calves from other calves or from adults before weaning. We developed a stochastic compartmental model of Map transmission in a closed dairy herd. The model reflects the Map infection process and herd management characteristics. Indirect transmission via the environment was modelled explicitly. Six infection states (susceptible, resistant, transiently infectious, latently infected, subclinically infected, and clinically affected) and two contaminated farm area environments (whole farm and calf area) were modelled. Calves were housed in hutches, individual indoor pens, or group indoor pens. Two different levels of exposure of calves to a farm environment contaminated by adults were possible: no exposure and indirect exposure through fomites. Three herd sizes were studied. We found that contacts between calves before weaning did not influence Map transmission in a herd, whereas the level of exposure of calves to an environment contaminated by adults and the starting age of exposure of calves to adults were pivotal. Early culling of clinically affected adults led to a lower prevalence of infectious adults over time. The results were independent of herd size. Despite the many transmission routes that are known, the best control approach is to limit the exposure of calves to adult faeces through the systematic separation of adults and calves in combination with hygiene measures. Reducing contact between calves does not appear effective.

This paper describes the clinical, pathological, and microbiologic aspects of paratuberculosis (Johne's disease) in a dairy Gyr herd in the State of Paraíba, 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.

Mycobacterium avium subsp. paratuberculosis (Map) is a potential human pathogen known to be present in raw milk from infected dairy herds. Current pasteurisation regimes do not totally inactivate Map resulting in the possibility of viable cells being present in pasteurised milk used for Cheddar cheese production. A laboratory-based method, ensuring strict safety precautions, was developed to manufacture 800-g Cheddar blocks, experimentally contaminated (postpasteurisation) with two different strains of Map. The composition of the model Cheddar produced was consistent with commercial product. Syneresis of the cheese curd caused a 1 log10 concentration of Map numbers from milk to cheese for a strain isolated from pasteurised milk. The type strain NCTC 8578 did not show a similar concentration effect, but did however survive the Cheddar manufacturing process. A small percentage (