rapid and transient activation of gene expression in peripheral blood mononuclear cells from johne's disease positive cows exposed to mycobacterium paratuberculosis in vitro.mycobacterium avium subspecies paratuberculosis (m. paratuberculosis) is the causative agent of johne's disease in ruminants. m. paratuberculosis is a slow-growing intracellular bacterium and infections with m. paratuberculosis can persist in a subclinical state for several years. an early and appropriate t cell-mediated cytotoxic response (th1-like) to m. paratuberculosis infection is often replaced with an antibody or th 2-like response as infected animals move toward a progressively more clin ...200414687562
[paratuberculosis eradication programs in northrhine-westfalia].since 1993 a voluntary eradication program for bovine paratuberculosis is established in northrhine-westfalia. after an effectivity control of the serological diagnostics it is combined with the fecal culture since august of 2000. parallel use of both methods is necessary for a successful eradication. it could be monitored that a high percentage of the newly bought cattle in the herds participating in the eradication program was considered positive. since paratuberculosis eradication is time and ...200212596567
paratuberculosis recognized as a problem at last: a review.this article attempts to review briefly current opinions on johne's disease, or paratuberculosis, in ruminants caused by mycobacterium avium subsp. paratuberculosis. paratuberculosis has been known to be prevalent in domestic livestock, such as cattle, goats, and sheep, for more than a century. despite this knowledge only minor efforts have been made to control the disease and, with the attention being focussed on the eradication of other diseases, the problem of paratuberculosis has been neglec ...200011087130
[detection of mycobacterium avium subsp. paratuberculosis from the testicles of a clinically infected breeding animal].during a post mortem of a six year old simmental bull with severe paratuberculosis infection the testicles were further examined by pathological, histological and microbiological methods. no gross or histological lesions could be observed. single acid fast organisms were detected in smears taken from sterile testicle tissue. tissue material was additionally cultured in mycostatin culture media and after 8 weeks of incubation acid fast colonies were demonstrated. polymerase chain reaction with dn ...200415046460
development of a polymerase chain reaction test to confirm mycobacterium avium subsp. paratuberculosis in culture.a polymerase chain reaction (pcr) assay for confirmation of mycobacterium avium subsp. paratuberculosis was developed using the primer set derived from ismav2. the pcr product was 494 base pairs (bp) and could be digested with clai, which produced 311- and 183-bp fragments. no amplification of 494-bp dna fragment was detected from dna of other mycobacterium spp., including mycobacterium avium complex, other bacteria, including escherichia coli, pseudomonas aeruginosa, actinobacillus pleuropneumo ...200415053361
epidemiology of paratuberculosis in wild ruminants studied by restriction fragment length polymorphism in the czech republic during the period two studies carried out during the period 1995-1998, paratuberculosis was diagnosed in domestic and wild ruminants in the czech republic. the isolated mycobacterium avium subspecies paratuberculosis strains were analysed by standardised restriction fragment length polymorphism (rflp) [pavlik, i., horvathova, a., dvorska, l., bartl, j., svastova, p., du maine, r., rychlik, i., 1999. j. microbiol. methods 38, 155-167]. in december 1992, 19 late pregnant charolais heifers were imported to the cz ...200011118709
parallel faecal and organ mycobacterium avium subsp. paratuberculosis culture of different productivity types of cattle.faecal (at least 3 months before slaughtering) and organ examinations were carried out in 611 animals (497 dairy, 69 dual-purpose and 44 beef cattle) originating from eight paratuberculosis infected cattle herds. the diagnosis in cattle was established by routine intestinal culture (ileum and the adjacent lymph nodes) after slaughter. in selected 132 animals, post-mortem intensive culture was performed on tissue samples collected from the gastrointestinal tract (duodenum, jejunum, ileum, ileocec ...200011118716
serologic survey for antibodies against mycobacterium a vium subsp. paratuberculosis in free-ranging cervids from norway.affinity between protein-g and immunoglobulins from red deer (cervus elaphus), moose (alces alces), roe deer (capreolus capreolus), and reindeer (rangifer tarandus tarandus) was tested in a competition binding assay. sera from red deer, reindeer, and moose inhibited the assay less than sera from cattle (less affinity), whereas sera from roe deer showed a slightly higher affinity to protein-g than did sera from cattle. the conclusion was made that protein-g could be used instead of anti-species a ...200415137486
disease survey of free-ranging grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia.samples from 17 free-ranging hunter-killed grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia, were collected during june-august 1999. all 17 deer appeared to be in good condition at the time of death. gross necropsies were performed, serum was collected for serologic evaluation of selected infectious disease agents, and feces and ectoparasites were collected for evaluation of internal and external parasites. serologic tests were positive for antibodies against bovine respiratory ...200415137493
mycobacterium avium subsp. paratuberculosis infection in cattle in austria, diagnosis with culture, pcr and elisa.serum samples from healthy, infected (n=11) and diseased (n=2) cattle as well as positive (n=17) and negative (n=41) reference sera were tested for antibodies to mycobacterium avium subsp. paratuberculosis with two elisa-methods (a-elisa, allied monitors, fayette, usa; h-elisa, institute of microbiology and animal diseases, veterinary university hannover). fecal samples of these animals were examined by pcr and culture. also field serum samples found to be positive (n=664) or inconclusive (n=158 ...200011118719
improved detection of mycobacterium avium subsp. paratuberculosis in milk by immunomagnetic pcr.the potential use of a novel immunomagnetic pcr (ims-pcr) technique as a rapid method to screen milk samples for the presence of mycobacterium avium subsp. paratuberculosis (m. ptb) was assessed. immunomagnetic separation (ims) for m. ptb, developed at queen's university, belfast, was applied to milk samples prior to is900 pcr in order to selectively concentrate any m. ptb cells present and, at the same time, separate the cells from constituents of milk likely to inhibit subsequent pcr. this inc ...200011118722
development of a peptide-mediated capture pcr for detection of mycobacterium avium subsp. paratuberculosis in milk.based on phage display technology, a peptide-mediated magnetic separation technique was developed to facilitate selective isolation of mycobacterium avium subsp. paratuberculosis (m. paratuberculosis) from bulk milk of naturally infected dairy herds. nine recombinant bacteriophages binding to m. paratuberculosis were isolated from a commercial phage-peptide library encoding random 12-mer peptides. nucleotide sequencing revealed the deduced sequence of the binding peptides. one peptide with the s ...200212409405
progress in national control and assurance programs for ovine johne's disease in australia.since the detection of ovine johne's disease in australia in 1980, 578 flocks have been diagnosed as infected, with 442 of these still infected. the disease was initially believed to be confined to the central tablelands area of nsw, but has subsequently been shown to be more widely distributed. sheep strains of m. paratuberculosis are known to infect sheep and goats in south-eastern australia. although sheep strains have recently been identified in some cattle in australia, epidemiological evid ...200011118726
gamma interferon production by bovine gamma delta t cells following stimulation with mycobacterial mycolylarabinogalactan peptidoglycan.a large percentage of lymphocytes in the blood of cattle express the gamma delta t-cell receptor, but specific functions for these cells have not yet been clearly defined. there is evidence, however, that human, murine, and bovine gamma delta t cells have a role in the immune response to mycobacteria. this study investigated the ability of bovine gamma delta t cells to expand and produce gamma interferon (ifn-gamma) in response to stimulation with mycobacterial products. bovine gamma delta t cel ...200415271921
beetles as possible vectors of infections caused by mycobacterium avium species.mycobacteria were not isolated from any of 229 beetle imagoes of 29 species originating from 14 distinct localities in the czech and slovak republics: 186 imagoes (34 samples) and 43 imagoes (12 samples) from the wild and herds with paratuberculosis infected ruminants, respectively. from 75 environmental samples taken from barns with infected ruminants, mycobacterium avium subsp. paratuberculosis was isolated from five scrapings of the floors in barns and a feed processing room. from bran and pe ...200415327799
specific seroreactivity of crohn's disease patients against p35 and p36 antigens of m. avium subsp. paratuberculosis.crohn's disease (cd) is a chronic inflammatory bowel disease that is similar to johne's disease in ruminants. recent data have strengthened the association of m. avium subsp. paratuberculosis (m. paratuberculosis) with cd. to provide more evidence of an etiological association, antibody reactivities from cd patients were tested by immunoblotting against recombinant antigens that were identified previously from our m. paratuberculosis genomic library. two clones (designated pmptb#40 (3.2-kb inser ...200011118734
maximum-likelihood estimation of sensitivity and specificity of elisas and faecal culture for diagnosis of paratuberculosis.the accuracy of three diagnostic tests for paratuberculosis was evaluated using maximum-likelihood estimation of sensitivity and specificity. we also explored the variety of estimates that can be obtained if the tests are to be used in populations of different composition with regard to infection and disease states. two enzyme-linked immunosorbent assays (elisas) were evaluated separately with the faecal culture (fc). the study was carried out as a cross-sectional field study to cover all likely ...200211830293
in situ hybridization method for studies of cell wall deficient m. paratuberculosis in tissue samples.cell wall deficient forms of mycobacteria may be important in the pathogenesis of crohn's disease and sarcoidosis. however, no method has been available to localize this type of organisms in tissue sections. we developed an in situ hybridization method for the demonstration of mycobacterium paratuberculosis spheroplasts (cell wall deficient forms) in paraffin embedded tissue sections.m. paratuberculosis spheroplasts were prepared by treatment with glycine and lysozyme. pieces of beef were inject ...200011118736
use of multilocus variable-number tandem-repeat analysis for typing mycobacterium avium subsp. paratuberculosis.the etiology of crohn's disease in humans is largely unknown. clinical signs of crohn's disease partly resemble the clinical picture of johne's disease in ruminants caused by mycobacterium avium subsp. paratuberculosis. because of the high prevalence of these bacteria in (products of) ruminants and their remarkable thermostability, concern has been raised about the possible role of these bacteria in the pathogenesis of crohn's disease. in an attempt to develop a molecular typing method to facili ...200415528690
review article: mycobacterium avium subsp. paratuberculosis as one cause of crohn's disease.a number of theories regarding the aetiology of crohn's disease have been proposed. diet, infections, other unidentified environmental factors and immune disregulation, all working under the influence of a genetic predisposition, have been viewed with suspicion. many now believe that crohn's disease is a syndrome caused by several aetiologies. the two leading theories are the infectious and autoimmune theories. the leading infectious candidate is mycobacterium avium subspecies paratuberculosis ( ...200111207508
immunoreactivity of the mycobacterium avium subsp. paratuberculosis 19-kda lipoprotein.the mycobacterium tuberculosis 19-kda lipoprotein has been reported to stimulate both t and b cell responses as well as induce a number of th1 cytokines. in order to evaluate the mycobacterium avium subsp. paratuberculosis (m. avium subsp. paratuberculosis) 19-kda lipoprotein as an immunomodulator in cattle with johne's disease, the gene encoding the 19-kda protein (map0261c) was analyzed.200515663791
comparison of two dna extractions and nested pcr, real-time pcr, a new commercial pcr assay, and bacterial culture for detection of mycobacterium avium subsp. paratuberculosis in bovine this study, 5 combinations of 2 dna extractions and 3 polymerase chain reaction (pcr) techniques were compared with culture for the detection of mycobacterium paratuberculosis directly from bovine feces. these combinations included a new commercial extraction technique combined with a commercial pcr/southern blot technique, nested pcr (npcr), or real-time pcr, and a university-developed extraction combined with npcr or real-time pcr. four of the 5 combinations had statistically similar sensit ...200312661717
on-farm batch pasteurization destroys mycobacterium paratuberculosis in waste milk.a recent dairy survey conducted in 1996 by the national animal health monitoring system suggests between 20 and 40% of dairy herds in the united states have some level of johne's disease. this figure will continue to increase unless producers implement management regimes that will help control the spread of this disease within their herds. the neonatal calf is the target for infection with mycobacterium paratuberculosis, the causative agent of johne's disease. calves become infected via exposure ...200111233038
application of different methods for the diagnosis of paratuberculosis in a dairy cattle herd in argentina.paratuberculosis (ptbc) has a high prevalence in argentina, that affects dairy and beef cattle. the culture is the gold standard to the diagnosis of the disease. mycobacterium avium ssp. paratuberculosis (m. paratuberculosis), the aetiological agent, is difficult to isolate and grow in culture. in this study, 24 randomly selected cows of the fresian breed from a dairy herd with a history of ptbc were used to evaluate the performance of different diagnostic techniques. these animals did not show ...200312710496
pooled fecal culture sampling for mycobacterium avium subsp. paratuberculosis at different herd sizes and prevalence.a stochastic spreadsheet model was developed to obtain estimates of the costs of whole herd testing on dairy farms for mycobacterium avium subsp. paratuberculosis (map) with pooled fecal samples. the optimal pool size was investigated for 2 scenarios, prevalence (a low-prevalence herd [< or = 5%] and a high-prevalence herd [> 5%]) and for different herd sizes (100-, 250-, 500- and 1,000-cow herds). all adult animals in the herd were sampled, and the samples of the individuals were divided into e ...200312735345
preliminary characterization of chemically generated mycobacterium avium subsp. paratuberculosis cell wall deficient forms (spheroplasts).cell wall deficient forms (cwd, spheroplasts) genetically indistinguishable from m. avium subsp. paratuberculosis (map) have been isolated from patients with crohn's disease and sarcoidosis. these map cwd may be important in the pathogenesis of these diseases and in johne's disease in other animal species. cwd forms are extremely difficult to isolate and generally revert to cell wall competent forms (cwc) when cultured in vitro. cultured map strain 19698 were chemically treated to generate suffi ...200312935751
expression cloning of gamma interferon-inducing antigens of mycobacterium avium subsp. paratuberculosis.three recombinant proteins, map10, map39, and map41, produced based on nucleotide sequences obtained from the screening of mycobacterium avium subsp. paratuberculosis genomic library expressed in escherichia coli significantly elicited gamma interferon production in peripheral blood mononuclear cells from infected cattle. two of these proteins were members of the ppe protein family.200515908411
molecular analyses of mycobacteria other than the m. tuberculosis complex isolated from northern ireland cattle.mycobacteria other than the mycobacterium tuberculosis complex (mott), isolated from northern ireland cattle, were identified by pcr amplification of the 16s rrna gene, and subsequent reverse cross blot hybridisation and sequence analyses. elucidation of the mott species was to facilitate specificity testing of new and existing diagnostic test reagents for bovine tuberculosis. the presence of the genes for potential diagnostic antigens: mpb70, mpb64, esat-6 and cfp-10 in the isolated mott specie ...200515917138
the experimental infection of cattle with mycobacterium johnei. i. calves inoculated intravenously. 195813563683
cytokine secretion by peripheral blood mononuclear cells from cows infected with mycobacterium compare cytokine secretion patterns of peripheral blood mononuclear cells (pbmc) from healthy cows and cows subclinically and clinically infected with mycobacterium paratuberculosis.200010895895
immunoperoxidase studies of cell mediated immune effector cell populations in early mycobacterium avium subsp. paratuberculosis infection in sheep.immunoperoxidase (ipx) labelling for cd4, cd8, tcr-gammadelta, wc1, cd1b, ifn-gamma, cd45r, cd56 and lysozyme was used to investigate changes in cell mediated immune effector cell populations in the intestinal peyer's patches (pp) and mesenteric lymph nodes of lambs, 2 and 4 months after experimental infection with low doses of sheep strain mycobacterium avium subsp. paratuberculosis (m. a. paratuberculosis). the organism was cultured from the tissues of each infected lamb, but histological lesi ...200414741134
newly developed primers for the detection of mycobacterium avium subspecies paratuberculosis.recent publications reported the existence of is900 like sequences in mycobacteria different from mycobacterium avium subspecies paratuberculosis (map). the primers used for is900 detection of map have amplified these sequences causing false positive results. in this study, we have developed two new pcr assays for the detection of map. the first assay is based on the is900 sequence using primers different from the ones previously reported, the second assay on the f57 sequence. the specificity of ...200415145498
a cloned dna probe for the detection of mycobacterium paratuberculosis.dna extracted from mycobacterium paratuberculosis, which had been isolated from a cow with clinical johne's disease, was used to make a gene library in the escherichia coli expression vector phage lambda gt11. plaque-lifts were made from the library onto nitrocellulose membranes. these were screened by differential hybridization using radiolabelled chromosomal dna from m. paratuberculosis and mycobacterium phlei. by this method six recombinants that hybridized to m. paratuberculosis but not to m ...198916031516
paratuberculosis in farmed and free-living wild ruminants in the czech republic (1999-2001).due to the occurrence of the infection of mycobacterium avium subspecies paratuberculosis among domestic ruminants and the rapid development of farmed deer industry and the market of cloven-hoofed game we have carried surveys of paratuberculosis, beginning in 1997, in the most common four species of wild ruminants in the czech republic [pavlik et al., vet. microbiol. 77 (2000) 231-251]. from 1999 the prevalence of paratuberculosis has been slightly reduced in all three types of husbandry of wild ...200415261995
review of possible links between the clinical expression of paratuberculosis and deficiency of macro and micronutrients.published information on aspects of the epidemiology of paratuberculosis was reviewed to examine the hypothesis that clinical expression of disease may be induced by deficiencies or imbalances of micronutrients. the progression of paratuberculosis and the development of clinical signs, although innately linked with the process of becoming infected with mycobacterium avium subsp paratuberculosis, are mostly controlled by factors other than those predisposing to the acquisition of the organisms. t ...200415359965
efficacy of immunologic assays for the detection of johne's disease in dairy cows fed additional energy during the periparturient period.this study was designed to evaluate if the immunosuppression typically observed during the immediate periparturient period (3 weeks before and after calving) in dairy cows influences the effectiveness of diagnostic tests for the detection of johne's disease; and, if providing additional energy to the cows during this period would minimize any immunosuppressive effects. twelve dairy cows naturally infected with mycobacterium paratuberculosis were fitted with rumen cannulas in late gestation and a ...200415460323
use of rmpb70 protein and esat-6 peptide as antigens for comparison of the enzyme-linked immunosorbent, immunochromatographic, and latex bead agglutination assays for serodiagnosis of bovine tuberculosis.current assays used to detect mycobacterium bovis infection lack accuracy, especially for recently infected animals, or are impractical for rapid field diagnostic applications. to overcome these limitations with serological assays, a synthetic peptide derived from early secretory antigenic target 6 (esat6-p) and a recombinant major secreted immunogenic protein (rmpb70) of m. bovis were used in an enzyme-linked immunosorbent assay (eia), an immunochromatographic assay (icga), and a latex bead agg ...200516145098
mycobacterium avium ssp. paratuberculosis recombinant heat shock protein 70 interaction with different bovine antigen-presenting cells.abstract heat shock proteins (hsp) can deliver antigen into the major histocompatibility complex class i presentation pathway of antigen-presenting cells (apc), a process called cross priming, thus stimulating antigen-specific cd8+ t-cell reactions. hsp were shown to elicit proinflammatory responses in apc. both processes require interaction of hsp with apc via specific receptors. this study describes the interaction of recombinant hsp70 (rhsp70) of mycobacterium avium subspecies paratuberculosi ...200515787741
[from farm to fork--mycobacterium avium ssp. paratuberculosis (map) as zoonotic agent?].mycobacterium avium ssp. paratuberculosis (map) is the causative agent of the paratuberculosis (para tb) in ruminants. in addition, this pathogen has been suspected to be implicated in the pathogenesis of morbus crohn disease (mc), causing chronic inflammatory intestine changes of humans. the participation of map in this illness is discussed intensively and has very contradictory opinions. on the one hand several times succeeded in proving map dna in changed human tissues as well as, in recent t ...200516206925
mycobacterium paratuberculosis detection in bovine feces is improved by coupling agar culture enrichment to an is900-specific polymerase chain reaction assay.the feasibility of coupling an agar culture enrichment step with gene amplification (ace-pcr) as a means to improve turnaround time and detect mycobacterium paratuberculosis (mpt) in the presence of contaminants was investigated. fecal samples from 463 pennsylvania dairy cows were cultured in duplicate sets. one replicate from each set was processed and interpreted according to standard culture (sc) protocol, whereas cultures from the second replicate were harvested at 6 weeks postinoculation; d ...199912968758
efficacy of various pasteurization time-temperature conditions in combination with homogenization on inactivation of mycobacterium avium subsp. paratuberculosis in milk.the effect of various pasteurization time-temperature conditions with and without homogenization on the viability of mycobacterium avium subsp. paratuberculosis was investigated using a pilot-scale commercial high-temperature, short-time (htst) pasteurizer and raw milk spiked with 10(1) to 10(5) m. avium subsp. paratuberculosis cells/ml. viable m. avium subsp. paratuberculosis was cultured from 27 (3.3%) of 816 pasteurized milk samples overall, 5 on herrold's egg yolk medium and 22 by bactec cul ...200515932977
detection of viable mycobacterium avium subsp. paratuberculosis using luciferase reporter systems.plasmid- and phage-based firefly luciferase reporter constructs were evaluated as rapid detection systems for viable mycobacterium avium subsp. paratuberculosis (map). a map strain bearing a luciferase-encoding plasmid was detectable at 100 cells/ml in skim milk and 1000 cells/ml in whole milk. three luciferase-encoding mycobacteriophage were evaluated for detection of wild-type map. the best of these, phae85, allowed detection of >1000 cells/ml within 24-48 h. membrane filtration did not improv ...200415992288
prevalence of and risk factors for paratuberculosis in purebred beef estimate the prevalence of paratuberculosis in purebred beef cattle in texas and identify risk factors for seropositivity.200515776952
inducible nitric oxide synthase immunoreactivity in the granulomatous intestinal lesions of naturally occurring bovine johne's disease.inducible nitric oxide synthase (inos) is important in the control of a number of intracellular pathogens, including mycobacteria, and is a marker of classic macrophage activation. in human granulomatous diseases such as leprosy, a spectrum of granulomatous lesions is described, ranging from the tuberculoid to lepromatous types. tuberculoid granulomas are associated with enhanced inos production and improved clinical outcomes over the lepromatous types. the aim of this study is to determine whet ...200515872370
histopathological classification of lesions associated with natural paratuberculosis infection in cattle.paratuberculosis-associated lesions in 116 naturally infected adult cows, with or without clinical signs, were classified histopathologically. tissue samples obtained focused on gut-associated lymphoid tissue. lesions were divided into five categories. focal lesions (n=68 cases), consisted of small granulomas in the ileal and jejunal lymph nodes or the ileocaecal lymphoid tissue. in the multifocal type (n=13 cases), small granulomas or scattered giant cells appeared in some intestinal villi, as ...200516045917
absence of mycobacterium avium subspecies paratuberculosis components from crohn's disease intestinal biopsy tissues.crohn's disease is a chronic human intestinal inflammatory disorder for which an etiologic agent has not been identified. johne's disease is a similar chronic enteric granulomatous disease of ruminant species and has been used as a model of crohn's disease. johne's disease has been proven to be caused by mycobacterium avium subspecies paratuberculosis (m. avium ss paratuberculosis). it has been proposed that m. avium ss paratuberculosis may also cause crohn's disease. this is of particular conce ...200315931311
infection rates in reactors to an absorbed elisa used in a test and cull program for bovine johne's determine the proportion of cattle, whose sera gave positive reactions in a commercial enzyme linked immunosorbent assay (elisa) for bovine johne's disease, that were confirmed infected with mycobacterium avium subsp paratuberculosis by histology and culture of tissues.200415149076
the ability of mycobacterium avium subsp. paratuberculosis to enter bovine epithelial cells is influenced by preexposure to a hyperosmolar environment and intracellular passage in bovine mammary epithelial cells.mycobacterium avium subsp. paratuberculosis is the cause of johne's disease in cattle and other ruminants. m. avium subsp. paratuberculosis infection of the bovine host is not well understood; however, it is assumed that crossing the bovine intestinal mucosa is important in order for m. avium subsp. paratuberculosis to establish infection. to examine the ability of m. avium subsp. paratuberculosis to infect bovine epithelial cells in vitro, madin-darby bovine kidney (mdbk) epithelial cells were ...200616622223
new latex bead agglutination assay for differential diagnosis of cattle infected with mycobacterium bovis and mycobacterium avium subsp. paratuberculosis.extensive studies have shown that the current assays used to identify cattle infected with mycobacterium bovis or mycobacterium avium subsp. paratuberculosis are not sufficiently sensitive and specific to detect all infected animals, especially animals recently infected with the pathogens. in the present report we show that these limitations might be overcome with a latex bead agglutination assay (lbaa). with the specific immunodominant epitope (esat6-p) of m. bovis, we developed an lbaa and enz ...200415539508
development of a johne's disease infection model in laboratory rabbits following oral administration of mycobacterium avium subspecies assess the rabbit as a model for the study of johne's disease pathogenesis, a breeding group of adult and juvenile new zealand white rabbits were orally challenged with three doses of the mycobacterium avium subspecies paratuberculosis wildtype bovine strain, clij623, on three occasions. faecal culture, post-mortem tissue bacteriological culture and histopathology were used to monitor the disease progression in the rabbits for more than 2 years. of 4 adult and 16 juvenile orally dosed rabbits ...200415708817
secreted antigens of mycobacterium avium subspecies paratuberculosis as prominent immune targets.we here describe the identification and characterization of three novel secreted mycobacterium avium subsp. paratuberculosis antigens of 9, 15 and 34 kda (map2609, map2942c and map0210c, respectively) by screening a genomic expression library with a serum of a naturally infected clinical cow. the 9, 15 and 34 kda antigens display strong homology to previously described m. tuberculosis antigens, tb8.4, mpt53 and erp, respectively. furthermore, these antigens were shown to be recognized by antibod ...200616413703
the respiratory tract as a hypothetical route of infection of cattle with mycobacterium avium subspecies paratuberculosis. 200415088986
protothecal enteritis as a cause of protein-losing enteropathy in a bull.prototheca spp are achlorophyllic saprophytic algae found in wastewater, sewage, agricultural waste, and possibly elsewhere in the environment. infections with these organisms have been reported in cattle, humans, and dogs; affected cattle commonly develop mastitis. a 5-year-old brahman-cross bull was evaluated because of a history of diarrhea and weight loss. the history and physical examination and clinicopathologic findings were similar to those associated with granulomatous enteritis caused ...200516279394
the distribution of mycobacterium avium ssp. paratuberculosis in the environment surrounding minnesota dairy farms.the objective of this study was to characterize the distribution of mycobacterium paratuberculosis (map) in the environment of infected and uninfected minnesota dairy farms. eighty herds known to be infected from minnesota's johne's disease control program (jdcp) and 28 herds known to be uninfected from minnesota voluntary johne's disease herd status program (vjdhsp) were sampled. fecal samples from up to 100 cows in each herd were cultured in pools of 5 cows. two environmental samples were obta ...200415375057
identification of members of mycobacterium avium species by accu-probes, serotyping, and single is900, is901, is1245 and is901-flanking region pcr with internal standards.from mycobacterium avium species mycobacterium avium subsp. paratuberculosis (n=961), mycobacterium a. avium (n=677), mycobacterium a. silvaticum (n=5), and mycobacterium a. hominissuis (n=1566) were examined, and from mycobacterium tuberculosis complex m. tuberculosis (n=2), mycobacterium bovis (n=13), m. bovis bcg (n=4), and mycobacterium caprae (n=10) were examined. from other mycobacterial species mycobacterium intracellulare (n=60) and atypical mycobacteria (n=256) including mycobacterium f ...200616061296
mycobacterium bovis cultured from commercially pasteurized cows' milk: laboratory cross-contamination.the ability of mycobacterium paratuberculosis to survive the commercial pasteurization process of raw milk remains controversial. in a study undertaken in venezuela to culture m. paratuberculosis from commercially pasteurized cows' milk, 83-200 ml containers of milk were processed and cultured on herrold's egg yolk slants. no m. paratuberculosis was cultured but a total of six colonies of mycobacterium bovis were isolated from one container each from two different milk providers. because laborat ...200616766143
mitogen activated protein kinase p38 pathway is an important component of the anti-inflammatory response in mycobacterium avium subsp. paratuberculosis-infected bovine monocytes.we investigated the role of cell signaling through the mitogen-activated protein kinase-p38 (mapk p38) pathway on the antimicrobial functions and cytokine expression by bovine monocytes after ingestion of mycobacterium avium subsp. paratuberculosis. we evaluated the dynamic secretion of interleukin (il)-10, il-12 and tumor necrosis factor-alpha (tnf-alpha) as well as phagosome acidification and organism killing at several time points after in vitro infection of bovine monocytes with m. avium sub ...200616716561
identification of diagnostic proteins in mycobacterium avium subspecies paratuberculosis by a whole genome analysis approach.mycobacterium avium subspecies paratuberculosis (m. paratuberculosis) is an economically significant veterinary pathogen that causes johne's disease in cattle and sheep. there is a critical need for improved diagnostic tests to detect m. paratuberculosis infection in these animals. as with many other animal diseases, efforts need to be concentrated on the development of simple, rapid, noninvasive tests that can be performed by veterinarians or animal producers without expensive laboratory equipm ...200616957356
early induction of humoral and cellular immune responses during experimental mycobacterium avium subsp. paratuberculosis infection of calves.johne's disease (paratuberculosis) of cattle is widespread and causes significant economic losses for producers due to decreased production and poor health of affected animals. the chronic nature of the disease and the lack of a reproducible model of infection hinder research efforts. in the present study, instillation of mycobacterium avium subsp. paratuberculosis into the tonsillar crypts of neonatal calves resulted in peripheral colonization as detected by antemortem culture of feces and post ...200312933856
molecular epidemiology of types i/iii strains of mycobacterium avium subspecies paratuberculosis isolated from goats and cattle.molecular characterization of mycobacterium avium subsp. paratuberculosis (m. a. paratuberculosis) isolates classifies them into three groups: cattle or type ii, sheep or type i, and intermediate or type iii. to avoid problems associated with characterization of extremely slow growth strains, pcr-based techniques that divide the m. a. paratuberculosis strains in two main groups (cattle or type ii, and sheep or types i/iii) can be performed. the objectives of this study were to characterize the m ...200616500045
prevalence estimates for paratuberculosis adjusted for test variability using bayesian analysis.the elisa tests that are available to detect an infection with mycobacterium avium subsp. paratuberculosis (map) have a limited validity expressed as the sensitivity (se) and specificity (sp). in many studies, the se and sp of the tests are treated as constants and this will result in an underestimation of the variability of the true prevalence (tp). bayesian inference provided a natural framework for using information on the test variability (i.e., the uncertainty) in the estimates of test se a ...200312941553
is900-pcr-based detection and characterization of mycobacterium avium subsp. paratuberculosis from buffy coat of cattle and sheep.johne's disease is one of the main causes of economic losses in ruminants and a major health hazard in the developing and developed world. up till now, many microbiological, serological and molecular methods have been tried for the detection of mycobacterium avium subsp. paratuberculosis (map). in this study, we attempt a pcr-based detection of is900, distinct insertion sequences of map from the buffy coat of cattle (n=262) and sheep (n=78), and direct genotyping by single strand conformational ...200616300910
risk of transmission of mycobacterium avium ssp. paratuberculosis by embryo transfer of in vivo and in vitro fertilized bovine embryos.over a 5-year interval, experiments were conducted to determine if mycobacterium avium ssp. paratuberculosis (map) is associated with in vivo and in vitro fertilized (ivf) embryos and whether it can be transmitted by embryo transfer. the present studies included: collection of embryos from five asymptomatic, naturally infected donors and transfer to uninfected recipients; collection of oocytes from two naturally infected donors with overt clinical signs; exposure of in vivo and ivf embryos to ma ...200616337678
modified culture protocol for isolation of mycobacterium avium subsp. paratuberculosis from raw milk.a modified culture method using c18-carboxypropylbetaine (cb-18) and microscopic screening was evaluated for time to and limit of detection of mycobacterium avium subsp. paratuberculosis (map) in raw milk. bulk-tank milk samples were spiked with six different concentrations (10(1) to 10(6) cfu/ml) of map. samples were processed using two different protocols. the first protocol involved specimen processing with the zwitterionic detergent c18-carboxypropylbetaine (cb-18) and lytic enzymes followed ...200617199528
comparison of histopathology, cultivation of tissues and rectal contents, and interferon-gamma and serum antibody responses for the diagnosis of bovine paratuberculosis.the diagnosis of infection with mycobacterium avium subsp. paratuberculosis was studied in 12 cattle from infected dairy herds and four from non-infected herds. a comparison was made of (1) histopathological examination and bacterial culture of tissues, (2) culture of serial samples of rectal contents, and (3) examination of repeated blood samples for interferon-gamma (ifn-gamma) and antibody responses. tissue samples were taken from the small and large intestine and corresponding mesenteric lym ...200314554124
effects of supplemental energy on metabolic and immune measurements in periparturient dairy cows with johne's disease.the present study was designed to evaluate whether feeding supplemental energy would improve the metabolic profile and alleviate some of the immunosuppression typically noted during the periparturient period in dairy cows with johne's disease. twelve dairy cows naturally infected with mycobacterium paratuberculosis were fitted with rumen cannulas in late gestation and assigned to treatment groups: control, n = 6; or stuffed, n = 6. cows in the control group were allowed to consume feed ad libitu ...200314672182
attachment of mycobacterium avium subspecies paratuberculosis to bovine intestinal organ cultures: method development and strain differences.mycobacterium avium spp. paratuberculosis (map) causes chronic granulomatous inflammation of the intestinal tract in many species of animals, but the mechanisms of disease are poorly understood. attachment of bacteria to epithelial cells is a critical step in pathogenesis of many mucosal diseases. the goal of these studies was to develop an in vitro method to study attachment of map to bovine intestinal epithelial cells. short-term, bovine intestinal organ cultures were used to show a significan ...200515936903
relationship between mycobacterium avium subspecies paratuberculosis, il-1alpha, and traf1 in primary bovine monocyte-derived macrophages.mycobacterium avium subspecies paratuberculosis (map) is a facultative intracellular pathogen that resides in host macrophage cells. presently, little is known about how map is able to subvert the normal bacteriocidal functions of infected macrophages. previously, we reported that ileal tissues from map infected cattle contained high levels of interleukin-1 alpha (il-1alpha) and tumor necrosis factor receptor-associated factor 1 (traf1), relative to ileal tissues from uninfected cattle. high-lev ...200717328964
a major cell wall lipopeptide of mycobacterium avium subspecies paratuberculosis.mycobacterium avium subspecies paratuberculosis (map), the causative agent of johne disease in cattle and other ruminants, is proposed to be at least one of the causes of crohn disease in humans. map and mycobacterium avium subspecies avium, a closely related opportunistic environmental bacterium, share 95% of their genes and exhibit homologies of more than 99% between these genes. the identification of molecules specific for map is essential for understanding its pathogenicity and for developme ...200616339155
cytokine gene expression in peripheral blood mononuclear cells and tissues of cattle infected with mycobacterium avium subsp. paratuberculosis: evidence for an inherent proinflammatory gene expression cattle and other ruminants, infection with the intracellular pathogen mycobacterium avium subsp. paratuberculosis results in a granulomatous enteritis (johne's disease) that is often fatal. the key features of host immunity to m. avium subsp. paratuberculosis infection include an appropriate early proinflammatory and cytotoxic response (th1-like) that eventually gives way to a predominant antibody-based response (th2-like). clinical disease symptoms often appear subsequent to waning of the th ...200414977946
isolation of mycobacterium avium subsp paratuberculosis from environmental samples collected from farms before and after destocking sheep with determine whether mycobacterium avium subsp paratuberculosis could be isolated from soil-pasture, faecal, water and sediment samples on farms before and after removal of sheep with paratuberculosis. a feasibility study and subsequent field survey.200315086096
mycobacterium avium subsp. paratuberculosis in lake catchments, in river water abstracted for domestic use, and in effluent from domestic sewage treatment works: diverse opportunities for environmental cycling and human exposure.mycobacterium avium subsp. paratuberculosis from infected animals enters surface waters and rivers in runoff from contaminated pastures. we studied the river tywi in south wales, united kingdom, whose catchment comprises 1,100 km2 containing more than a million dairy and beef cattle and more than 1.3 million sheep. the river tywi is abstracted for the domestic water supply. between august 2002 and april 2003, 48 of 70 (68.8%) twice-weekly river water samples tested positive by is900 pcr. in rive ...200616751517
cytokine responses of bovine macrophages to diverse clinical mycobacterium avium subspecies paratuberculosis strains.mycobacterium avium subsp. paratuberculosis (map), the causative agent of johne's disease (jd) persistently infects and survives within the host macrophages. while it is established that substantial genotypic variation exists among map, evidence for the correlates that associate specific map genotypes with clinical or sub-clinical disease phenotypes is presently unknown. thus we studied strain differences in intracellular map survival and host responses in a bovine monocyte derived macrophage (m ...200616478544
uv light inactivation of mycobacterium avium subsp. paratuberculosis in milk as assessed by fastplaquetb phage assay and culture.uv light inactivation of mycobacterium avium subsp. paratuberculosis in middlebrook 7h9 broth and whole and semiskim milk was investigated using a laboratory-scale uv machine that incorporated static mixers within uv-penetrable pipes. uv treatment proved to be less effective in killing m. avium subsp. paratuberculosis suspended in milk (0.5- to 1.0-log(10) reduction per 1,000 mj/ml) than that suspended in middlebrook 7h9 broth (2.5- to 3.3-log(10) reduction per 1,000 mj/ml). the fastplaquetb pha ...200717435001
contribution of respiratory burst activity to innate immune function and the effects of disease status and agent on chemiluminescence responses by ruminant phagocytes in vitro.the mechanisms of interaction between phagocytes and different bacteria that help resolve lung infections or contribute to lung pathology are poorly defined. alveolar phagocytes (resident macrophages and recruited neutrophils) make a major contribution to innate immunity by mounting a respiratory burst that helps kill internalised bacteria. however, this ability may be altered during or after exposure to infection. this review considers the application and limitations of a variety of analytical ...200616678912
relationship between antibodies against mycobacterium avium subsp. paratuberculosis in milk and shape of lactation analyze how infection with mycobacterium avium subsp. paratuberculosis (map) affects the shape of lactation curves, a three-level hierarchical test-day model was set up with fat-corrected test-day milk yield (fctm) as response. milk samples from 6955 cows in 108 danish dairy herds were tested with elisa to detect antibodies against map. optical densities (ods) recorded on a continuous scale were standardized according to parity and stage of lactation. in addition to standardized ods (stod), s ...200415156998
mycobacterium avium subspecies paratuberculosis infection of cattle does not diminish peripheral blood-derived macrophage mycobactericidal activity.ruminants infected with mycobacterium avium subspecies paratuberculosis consistently develop a multibacillary form of disease that is centered on the ileum. mechanisms responsible for failure of macrophage function during multibacillary disease are incompletely characterized. our data suggest that mycobactericidal functions are present, and potentially enhanced, in monocyte-derived macrophages from m. avium subsp. paratuberculosis infected cattle. addition of cd4(+) t cells from infected animals ...200616884783
development of a method for bayesian nonparametric roc analysis with application to an elisa for johne's disease in dairy cattle.six hundred and sixty-eight dairy cattle were tested for johne's disease using a direct-fecal real-time polymerase chain reaction (rt-pcr), fecal culture, and serum enzyme-linked immunosorbent assay (elisa). likelihood ratios (lrs) were estimated for five categories of sample-to-positive (s/p) values for the elisa: <0.1, 0.1-0.249, 0.25-0.399, 0.4-0.999, > or =1.0. the statistical method assumed a single multinomial model for cross-classified rt-pcr, fecal culture results, and elisa category str ...200717482696
amplified fragment length polymorphism to detect clonal diversity and distribution of mycobacterium avium subspecies paratuberculosis in selected minnesota dairy cattle.the molecular ecology of mycobacterium avium subspecies paratuberculosis (map), the causative agent of johne's disease, is not well understood in the united states. in this study, a dna fingerprinting method, amplified fragment length polymorphism (aflp), was used to subtype the pathogen and assess the clonal diversity of map in minnesota dairy herds. fifty-six fecal culture test-positive isolates from various minnesota counties and culture dates were analyzed in this study. the aflp identified ...200516130987
monensin might protect ontario, canada dairy cows from paratuberculosis milk-elisa positivity.our objective was to define the role of monensin sodium in protecting cows from being milk-elisa positive for paratuberculosis in ontario, canada dairy herds. in total, 4933 dairy cows from 94 herds were enrolled in this cross-sectional study. forty-four of the enrolled herds were selected purposively by their herd veterinarian and another 50 herds were randomly selected from a local milk production-recording agency. a herd-management survey was completed on each farm during the months of may th ...200616787675
isolation of mycobacterium avium subspecies paratuberculosis from non-ruminant wildlife living in the sheds and on the pastures of greek sheep and goats.this study aimed to: (1) investigate whether non-ruminant wildlife interfacing with dairy sheep and goats of four greek flocks endemically infected with mycobacterium avium subspecies paratuberculosis (map) harboured map and (2) genetically compare the strains isolated from the wildlife to those isolated from the small ruminants of these flocks. we cultured and screened, by polymerase chain reaction (pcr), pooled-tissue samples from 327 wild animals of 11 species for the map-specific is900 inser ...200817578601
clustering of mycobacterium avium subsp. paratuberculosis in rabbits and the environment: how hot is a hot spot?clustering of pathogens in the environment leads to hot spots of diseases at local, regional, national, and international levels. scotland contains regional hot spots of johne's disease (caused by mycobacterium avium subsp. paratuberculosis) in rabbits, and there is increasing evidence of a link between paratuberculosis infections in rabbits and cattle. the spatial and temporal dynamics of paratuberculosis in rabbits within a hot spot region were studied with the overall aim of determining envir ...200516204518
a novel enzyme-linked immunosorbent assay for diagnosis of mycobacterium avium subsp. paratuberculosis infections (johne's disease) in cattle.enzyme-linked immunosorbent assays (elisas) for the diagnosis of johne's disease (jd), caused by mycobacterium avium subsp. paratuberculosis, were developed using whole bacilli treated with formaldehyde (called welisa) or surface antigens obtained by treatment of m. avium subsp. paratuberculosis bacilli with formaldehyde and then brief sonication (called selisa). elisa plates were coated with either whole bacilli or sonicated antigens and tested for reactivity against serum obtained from jd-posi ...200616682472
current understanding of the genetic diversity of mycobacterium avium subsp. paratuberculosis.mycobacterium avium subsp. paratuberculosis (map) is the etiological agent of johne's disease (or paratuberculosis). paratuberculosis is a chronic gastroenteritis mainly affecting cattle, sheep and other ruminants. map is also of concern due to the heretofore unresolved issue of its possible role in crohn's disease in humans. we present here a review of map (i) mobile genetic elements; (ii) repetitive elements; (iii) single nucleotide polymorphisms; and (iv) whole-genome comparisons to study the ...200616697677
differential cytokine gene expression profiles in the three pathological forms of sheep paratuberculosis.johne's disease is a chronic inflammatory disease of the gut caused by infection with mycobacterium avium subspecies paratuberculosis (map). symptoms include wasting, diarrhoea, loss of condition and eventual death. three forms of johne's disease have been described in sheep - paucibacillary, multibacillary and asymptomatic. the paucibacillary form is characterized by an inflammatory, th1-type immune response. the multibacillary form of the disease, which disseminates the infection, is character ...200717697353
seroprevalence of antibodies against bovine leukemia virus, bovine viral diarrhea virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum in dairy cattle in saskatchewan.blood was drawn from 1530 dairy cows in 51 herds. for antibodies against bovine leukemia virus, mycobacterium avium subspecies paratuberculosis, and neospora caninum, 37.4%, 2.7%, and 5.6% of cows were test positive, respectively, while 29.2% of herds had unvaccinated animals with > or = 1:64 for bovine viral diarrhea virus.200515759829
the etiology of mycobacterium avium subspecies paratuberculosis in crohn's disease.the etiology of crohn's disease (cd) has drawn heated controversy in the literature. compelling evidence in the literature has accumulated lately that could incriminate the mycobacterium avium subspecies paratuberculosis (map), the well-known agent of john's disease in cattle. the evidence is isolation of the organism or its dna and rna, detection of the anti-map antibodies in crohn's patients, increasing incidents of cd in areas close to the cattle pastures, and the possibility of treating the ...200717914503
replication and long-term persistence of bovine and human strains of mycobacterium avium subsp. paratuberculosis within acanthamoeba protists are ubiquitous in the environment and form a potential reservoir for the persistence of animal and human pathogens. mycobacterium avium subsp. paratuberculosis is the cause of johne's disease, a systemic infection accompanied by chronic inflammation of the intestine that affects many animals, including primates. most humans with crohn's disease are infected with this chronic enteric pathogen. subclinical infection with m. avium subsp. paratuberculosis is widespread in domest ...200616391127
evaluation of a rapid fecal pcr test for detection of mycobacterium avium subsp. paratuberculosis in dairy cattle.a high-throughput taqman pcr assay for detection of bovine paratuberculosis was evaluated by using fecal samples from 1,808 dairy cattle in seven naturally infected herds and 347 dairy cattle in seven herds considered free of paratuberculosis. fecal, blood, and milk samples were submitted to laboratories where the pcr-based assay, three different fecal culture procedures for mycobacterium avium subsp. paratuberculosis (centrifugation, sedimentation, and the bactec filter concentration method), t ...200616928884
identification of proteins of potential diagnostic value for bovine paratuberculosis.previously we showed that mycobacterium paratuberculosis culture filtrates (cfs) contain more antigens that react with sera from infected cattle than do cellular extracts of the organism. the goal of the present study was to identify proteins of potential diagnostic value among these cf proteins. proteins of potential interest were first separated by 2-de. roughly 240 cf protein spots were detected on cbb-stained gels using phoretix 2d software. of these, 83% reacted with serum from m. paratuber ...200617022102
comparison of milk and serum enzyme-linked immunosorbent assays for diagnosis of mycobacterium avium subspecies paratuberculosis infection in dairy cattle.milk and serum samples from 35 dairy herds in 17 states were evaluated for cow- and herd-level mycobacterium avium subspecies paratuberculosis (map) antibody test agreement. evaluation of 6,349 samples suggested moderate agreement between milk and serum enzyme-linked immunosorbent assay (elisa) results, with a kappa value of 0.50. cow-level sensitivity (se) for 18 dairy operations with 1,921 animals was evaluated relative to fecal culture results. at the cow level, the milk elisa relative se was ...200617037612
comparative transcriptional analysis of human macrophages exposed to animal and human isolates of mycobacterium avium subspecies paratuberculosis with diverse genotypes.mycobacterium avium subsp. paratuberculosis is the causative agent of johne's disease in animals and has been hypothesized to be associated with crohn's disease in humans. recently, m. avium subsp. paratuberculosis isolates recovered from crohn's disease patients were shown to have limited diversity, implying the existence of human disease-associated genotypes and strain sharing with animals (a. h. ghadiali et al., j. clin. microbiol. 42:5345-5348, 2004). to explore whether these genotypic diffe ...200617057086
the association between mycobacterium avium subsp. paratuberculosis fecal shedding or clinical johne's disease and lactation performance on two minnesota, usa dairy farms.lactation performance of cows infected with mycobacterium avium subsp. paratuberculosis (map) was previously studied using only serum elisa as a diagnostic method. this study evaluated on two dairy farms in minnesota, usa the lactation performance (measures of health, production, reproduction, and survival) of cows shedding map in feces before calving and of cows culled with clinical signs consistent with johne's disease (jd) during the subsequent lactation. fecal samples were collected from 105 ...200717118473
immune responses in mice to mycobacterium avium subsp. paratuberculosis following vaccination with a novel 74f recombinant polyprotein.johne's disease (jd) is a chronic infectious disease of ruminants caused by mycobacterium avium subsp. paratuberculosis (map). here, we report the cloning and expression of a 74kda recombinant polyprotein (map74f) and its protective efficacy against map infection in mice. map74f was generated by the sequential linkage of the orfs of the approximately 17.6-kda c-terminal fragment of map3527 to the full-length orf of map1519, followed at the c-terminus with approximately 14.6-kda n-terminal portio ...200818243427
on the action of methotrexate and 6-mercaptopurine on m. avium subspecies paratuberculosis.clinical improvement in inflammatory bowel disease (ibd) treated with methotrexate and 6-mercaptopurine (6-mp) is associated with a decrease in pro-inflammatory cytokines. this has been presumed to indicate the mechanism of action of methotrexate and 6-mp. although controversial, there are increasingly compelling data that mycobacterium avium subspecies paratuberculosis (map) may be an etiological agent in some or all of ibd. we hypothesized that the clinical efficacy of methotrexate and 6-mp in ...200717252054
pulsed-field gel electrophoresis profile homogeneity of mycobacterium avium subsp. paratuberculosis isolates from cattle and heterogeneity of those from sheep and goats.mycobacterium avium subsp. paratuberculosis (map) causes paratuberculosis in animals and is suspected of causing crohn's disease in humans. characterization of strains led to classify paratuberculosis isolates in two main types, cattle type strains, found affecting all host species, and sheep type strains, reported affecting mainly sheep. in order to get a better understanding of the epidemiology of paratuberculosis a large set of map isolates obtained from different species over the last 25 yea ...200717352818
combined streptomycin-isoniazid-rifampin therapy in the treatment of johne's disease in a goat.johne's disease (paratuberculosis) is an insidious, invariably fatal, chronic disease of ruminants. an increasing role for the goat as a companion animal as well as its commercial use stimulated interest in attempting to treat johne's disease in this species. the disease tends to differ both clinically and pathologically in goats compared to cattle because the former species often has less severe intestinal involvement. it was, therefore, speculated that response to therapy may differ between ca ...198217422141
genetic resistance of mice to mycobacterium paratuberculosis is influenced by slc11a1 at the early but not at the late stage of infection.we have recently described the development of a luminescent mycobacterium paratuberculosis strain of bovine origin expressing the luxab genes of vibrio harveyi. with this luminescent isolate, fastidious and costly enumeration of cfu by plating them on agar can be replaced by easy and rapid luminometry. here, we have reevaluated the effect of slc11a1 (formerly nramp1) polymorphism on susceptibility to m. paratuberculosis, using this luminometric method. a series of inbred mouse strains were infec ...200818285491
augmentation of secreted and intracellular gamma interferon following johnin purified protein derivative sensitization of cows naturally infected with mycobacterium avium subsp. paratuberculosis.measurement of secreted interferon (ifn)-gamma has proven to be a valuable tool for the detection of animals infected with mycobacterial pathogens, including mycobacterium avium subsp. paratuberculosis. previous reports have suggested that tuberculin skin testing can influence the performance of the ifn-gamma assay. in the present study, healthy noninfected cows, and cows subclinically and clinically infected with m. paratuberculosis were administered an intradermal injection of johnin purified ...200717459831
experimental challenge models for johne's disease: a review and proposed international international committee of johne's disease (jd) researchers was convened to develop guidelines for jd challenge studies in multiple animal species. the intent was to develop and propose international standard guidelines for models based on animal species that would gain acceptance worldwide. parameters essential for the development of long-term and short-term infection models were outlined and harmonized to provide a "best fit" jd challenge model for cattle, goats, sheep, cervids, and mice. t ...200717467201
Displaying items 101 - 200 of 312