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paratuberculosis in iceland: epidemiology and control measures, past and present.paratuberculosis as well as the slow virus infections maedi/visna and jaagsiekte came to iceland in 1933 when 20 sheep of the karakul breed were imported from halle, germany. at least five of these sheep were subclinical carriers of paratuberculosis. within 16 years paratuberculosis together with the other karakul diseases (maedi/visna and jaagsiekte) almost ruined sheep farming, the main agricultural industry in iceland. the first clinical case of paratuberculosis in sheep was confirmed in 1938 ...200011118711
characterization of is900 loci in mycobacterium avium subsp. paratuberculosis and development of multiplex pcr typing.mycobacterium avium subsp. paratuberculosis is a pathogen that causes chronic inflammation of the intestine in many animals, including primates, and is implicated in crohn's disease in humans. it differs from other members of the m. avium complex in having 14-18 copies of is900 inserted into conserved loci in its genome. in the present study, genomic dna flanking 14 of these insertions was characterized and homologues in the mycobacterium tuberculosis and m. avium subsp. avium genomes were ident ...200010974106
kinetics of il-2 receptor expression on lymphocyte subsets from goats infected with mycobacterium avium subsp. paratuberculosis after specific in vitro stimulation.quantification of surface il-2r expression on activated lymphocytes by flow cytometry have recently been reported to be useful in measuring cellular immunity against mycobacterium avium subsp. paratuberculosis in goats (whist et al., 2000, vet. immunol. immunopathol. 73, 207-218). to characterise the phenotype of the peripheral lymphocytes expressing il-2r after in vitro stimulation with purified protein derivative (ppd) from m. a. paratuberculosis, cells were processed for dual or triple colour ...200011068065
results of multiple diagnostic tests for mycobacterium avium subsp. paratuberculosis in patients with inflammatory bowel disease and in controls.mycobacterium avium subsp. paratuberculosis has been incriminated as a cause of crohn's disease (cd); however, studies to date have been relatively small and generally only used a single diagnostic assay. the objective of the study was to reexamine the association of m. avium subsp. paratuberculosis and cd using multiple diagnostic tests. five methods were used to detect m. avium subsp. paratuberculosis infections in 439 inflammatory bowel disease (ibd) patients and 324 control subjects in the u ...200011101567
[first description of concomitant infection with tuberculosis and paratuberculosis in dairy sheep in argentina].the authors present the results of a comparative intradermal tuberculin test performed on dairy sheep to determine rates of reaction to bovine and avian purified protein derivative (ppd). test reactions were interpreted by palpation and measurement with a calliper. results were analysed by plotting the values obtained. agar gel immunodiffusion tests, growth in culture and histopathological examinations were also performed to allow differential diagnosis between tuberculosis and paratuberculosis. ...200011107623
use of a pcr method on fecal samples for diagnosis of sheep paratuberculosis.the high sensitivity of pcr compared to the difficulties of fecal culture in sheep prompted the development of pcr protocols for detection of mycobacterium avium subsp. paratuberculosis dna in sheep feces. although the pcr itself is well developed, and does not pose large technical problems, concentrating the bacteria from samples that may contain low numbers of bacilli using practical methods is still the main difficulty for the use of this technique. in this study, we describe an extraction pr ...200011118723
progress in national control and assurance programs for bovine johne's disease in australia.cattle strains of mycobacterium paratuberculosis are known to infect cattle, goats and alpaca in southeastern australia, where there are also significant numbers of farmed deer. although sheep strains have recently been identified in some cattle in australia, epidemiological evidence to date supports the distinction (between bovine johne's disease (jd), caused by cattle strains in cattle, goats and alpaca, and ovine jd, caused by sheep strains in sheep and goats) for the purposes of control and ...200011118729
further studies on the gs element. a novel mycobacterial insertion sequence (is1612), inserted into an acetylase gene (mpa) in mycobacterium avium subsp. silvaticum but not in mycobacterium avium subsp. paratuberculosis.we have recently described the gs element, found in mycobacterium avium subsp. paratuberculosis (map), mycobacterium avium subsp. silvaticum (mas) and some isolates of mycobacterium avium subsp. avium serotype 2 (maas2), which contains a set of genes of low gc% content, putatively associated with the biosynthesis, modification and transference of fucose to cell wall glycopeptidolipids. here we describe a further gene of low gc% content (mpa), within the gs element in map. mpa is a putative acety ...200011118730
vaccination against paratuberculosis of lambs already infected experimentally with mycobacterium avium subspecies paratuberculosis.to assess the protective value of a live-attenuated vaccine in sheep already exposed to mycobacterium avium subsp paratuberculosis and to investigate the progression of a systemic immune response in experimentally infected sheep.200010979513
presence of bacterial 16s ribosomal rna gene segments in human intestinal lymph follicles.there is currently no information regarding microbial agents inside the intestinal lymph follicles.200010994621
hspx is present within mycobacterium paratuberculosis-infected macrophages and is recognized by sera from some infected cattle.a portion of the gene encoding hspx has been previously identified as a sequence specific to mycobacterium avium subspecies paratuberculosis (hereafter referred to as m. paratuberculosis) based on dna hybridization experiments. in this study, rabbit antisera were raised against a recombinant protein of hspx fused to the escherichia coli maltose binding protein (mbp/hspx). immunoblots of lysates of m. paratuberculosis-infected macrophages probed with the rabbit antisera showed that hspx was prese ...200011000531
identification of cell wall deficient forms of m. avium subsp. paratuberculosis in paraffin embedded tissues from animals with johne's disease by in situ hybridization.m. avium subsp. paratuberculosis (m. paratuberculosis) is the causative agent of johne's disease (jd) in ruminants leading to enormous economical losses in dairy and meat industries worldwide. during the subclinical stage of the disease, the infected animals are difficult if not impossible to detect by the available diagnostic tests including the pcr based ones. although only considered an animal pathogen, cell wall deficient (cwd) forms of m. paratuberculosis have been isolated from patients wi ...200011018275
use of the polymerase chain reaction assay for the detection of mycobacterium avium subspecies paratuberculosis in blood and liver biopsies from experimentally infected sheep.to evaluate a polymerase chain reaction-based assay for the detection of mycobacterium avium subsp paratuberculosis in blood and liver biopsies from subclinically infected sheep.200011022290
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
biosecurity on dairy operations: hazards and risks.the objective here was to present a model for considering biosecurity related to infectious diseases on us dairy operations using a risk assessment framework. with the example of an important dairy cattle pathogen (mycobacterium paratuberculosis), i followed risk assessment steps to characterize risks related to the use of certain management practices and possible risk reduction within an infectious disease biosecurity program. biosecurity practices focus on the prevention of introduction of the ...200011049083
the pathology of spontaneous paratuberculosis in the north american bison (bison bison).gross and histopathologic examinations were performed on 70 north american bison (bison bison) from a mycobacterium avium paratuberculosis culture-positive herd. the bison examined were part of a breeding herd totaling 2,800 animals. eight of 70 (11%) animals had gross findings of intestinal mucosal thickening, and 16 of 70 (23%) of the animals had enlarged mesenteric lymph nodes. histologic lesions compatible with johne's disease were diagnosed in 30 of 70 (43%) bison on the basis of the demons ...200011055866
elisa and fecal culture for paratuberculosis (johne's disease): sensitivity and specificity of each method.the sensitivity and specificity of the elisa and fecal culture tests for paratuberculosis in dairy cattle are examined. elisa and fecal culture data from seven dairy herds where both fecal cultures and elisa testing was done concurrently are included. a cohort of 954 cattle including 697 parturient adults, cultured every 6 months from 10 herds followed over 4 years served as the basis to determine fecal culture sensitivity. the fecal culture technique utilized a 2g sample with centrifugation and ...200011118724
paratuberculosis in red deer (cervus elaphus hippelaphus) in the western alps.during the hunting seasons 1995-96 to 1997-98, 19 red deer from the upper susa valley (cottian alps) were examined for paratuberculosis (johne's disease). specific dna amplification on mesenteric lymph nodes detected mycobacterium avium paratuberculosis in 17 animals. ten of these red deer were tested for serum antibodies by the agid and elisa tests, nine being negative. three isolates from infected deer were genetically characterized by an arbitrarily primed polymerase chain reaction, and showe ...200011085463
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
distinct differences in repertoires of low-molecular-mass secreted antigens of mycobacterium avium complex and mycobacterium tuberculosis.antigens in a 4-week-old culture filtrate (cf) of mycobacterium avium subsp. avium were separated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by western blotting. the culture had minimal lysis of bacilli, giving a cf preparation consisting mainly of secreted proteins. comparison with a similar cf of mycobacterium tuberculosis with almost no contamination with intracellular proteins showed the presence of cross-reactive antigens homologous to the four components of ...200011101579
characterization of is900 loci in mycobacterium avium subsp. paratuberculosis and development of multiplex pcr typing 200011101687
genetic variation of susceptibility to mycobacterium avium subsp. paratuberculosis infection in dairy cattle.paratuberculosis is an infectious disease that is not easily amenable to classical control methods such as treatment and vaccination. experimental animal models suggest that there could be genetic factors responsible for susceptibility or resistance to infection with the causative agent, mycobacterium avium subsp. paratuberculosis. the aim of this study was to estimate genetic variation in susceptibility to paratuberculosis in dutch dairy cattle. data collected during a vaccination trial, conduc ...200011104291
epidemiology of paratuberculosis in wild ruminants studied by restriction fragment length polymorphism in the czech republic during the period 1995-1998.in 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
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
reduced formation of granulomata in gamma(delta) t cell knockout balb/c mice inoculated with mycobacterium avium subsp. paratuberculosis.the role of gamma(delta) t cells in the bovine immune response to mycobacterium avium subsp. paratuberculosis (m. paratuberculosis) infection is poorly understood. accordingly, using balb/c mice that are innately susceptible to m. paratuberculosis, we compared wild-type and gamma(delta) t cell knockout balb/c mice to study the protective roles of gamma(delta) t cells in m. paratuberculosis infection. ten-week-old mice were inoculated intraperitoneally with either a low dose (4 x 10(6) colony-for ...200011055864
modification of a bovine elisa to detect camelid antibodies to mycobacterium paratuberculosis.mycobacterium avium subsp. paratuberculosis infection, or johne's disease, reportedly has a low prevalence in south american camelid populations. recently, however, single cases in the united states as well as an outbreak of the disease in australian alpacas (lama pacos) have been described. to provide a rapid and cost-effective method of diagnosing johne's disease in this species, the bovine parachek((r)) johne's absorbed eia (csl, vic., australia) was modified to create a camelid-specific seru ...200011118718
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
automation of an absorbed enzyme immunoassay for the detection of mycobacterium paratuberculosis antibodies for an eradication program.as part of an ongoing johne's disease eradication program by the state of victoria, australia, the victorian veterinary pathology services (vvps) has been involved in testing over 150000 cattle samples per year for the presence of johne's-specific antibodies. the parachek kit (csl, victoria, australia) has been used throughout the project. this method was automated using a rosys 3300 and a plato 7 (dade/behring diagnostics) to pipette samples and the behring elisa processor 3 (dade/behring diagn ...200011118720
comparative sensitivity of various faecal culture methods and elisa in dairy cattle herds with endemic johne's disease.in three new south wales dairy cattle herds with endemic johne's disease, prevalence rates by faecal culture were determined to be 12, 18 and 22%, respectively. whole herd faecal culture was shown to detect markedly more infected cattle than whole herd testing by the emai absorbed elisa, particularly in the two herds with greatest prevalence. in the three study herds, five methods for whole herd faecal culture were compared in each. these included two methods based on primary culture on herrold' ...200011118721
transitions in immune responses to mycobacterium paratuberculosis.the host immune response to infection with mycobacterium paratuberculosis is paradoxical, with strong cell-mediated immune responses during the early, subclinical stages of infection and strong humoral responses during the late clinical stages of the disease. cell-mediated immune responses modulated by various t cell subsets are essential to provide protective immunity and prevent progression of the disease. secretion of cytokines by t cell populations serves to activate macrophages to kill inge ...200011118731
differences in the immune responses in lambs and kids vaccinated against paratuberculosis, according to the age of vaccination.in order to evaluate and compare the peripheral immune responses induced by the vaccination against paratuberculosis in relation with the age of immunization, two groups of lambs and goat kids were vaccinated at 15 days and 5 months old, respectively. a heat-killed commercial vaccine was inoculated subcutaneously and humoral and cellular immune responses were measured by an elisa and ifn-gamma assay, respectively, at 0, 30, 90, 180, 270 and 360 dpv in the lambs and 0, 30, 90 and 180 dpv in the c ...200011118732
lewis rats are not susceptible to oral infection with mycobacterium avium subsp. paratuberculosis.pathogenesis studies of mycobacterium avium subsp. paratuberculosis infection in ruminants are hampered by the long incubation time of the disease. a laboratory animal model with a shorter incubation time would facilitate research in this field. although small rodents are usually considered to be resistant to m.a. paratuberculosis infection, several susceptible murine strains have been found. to our knowledge, there are no detailed reports with regard to susceptibility in rats. the lewis rat is ...200011118733
bulk-tank milk elisa antibodies for estimating the prevalence of paratuberculosis in danish dairy herds.paratuberculosis (johne's disease) has been widespread in danish dairy herds for a long time but the herd-level prevalence has never been determined precisely. to evaluate the prevalence of paratuberculosis in danish dairy herds in various regions, an elisa based on a commercially available antigen was adapted for testing bulk-tank milk for the presence of antibodies to mycobacterium avium subsp. paratuberculosis. bulk-tank milk samples were collected from six milk-collecting centres from six di ...200010727740
mycobacterium paratuberculosis infection in two free-ranging alpine ibex.the authors report two cases of mycobacterium paratuberculosis infection in free-ranging alpine ibex (capra ibex) from two different herds in the western alps, italy. one ibex, found dead in october 1998, was in poor condition. the second animal died due to trauma following capture with a dart gun. the only gross lesions observed were the enlargement of the mesenteric and iliac lymph nodes. samples from both ibex tested positive to polymerase chain reaction for a primer set specific for the m. p ...200011107630
culture of strategically pooled bovine fecal samples as a method to screen herds for paratuberculosis.fecal samples from 733 cows in 11 dairy herds with a low prevalence of paratuberculosis were cultured for the presence of mycobacterium avium subsp. paratuberculosis both individually and after combining (pooling) in groups of 5. the culture procedure was the modified jorgensen method, which uses naoh and oxalic acid for decontamination and modified lowenstein-jensen agar slants for cultivation. pooling was performed by mixing fecal samples from 5 animals ordered by age, herein referred to as st ...200011108455
a cross-sectional study of paratuberculosis in 1155 danish dairy cows.in a cross-sectional study on milk samples from 1155 cows from 22 danish dairy herds, selected risk factors for paratuberculosis were identified. the diagnostic procedure used was an indirect enzyme-linked immuno-sorbent assay (elisa) to detect antibodies against mycobacterium avium subsp. paratuberculosis. a sample was considered test-positive if it had a corrected optical density >/=0. 025 (test sensitivity 71.4% and test specificity 89.7%). of the 1155 samples, 8.8% (102/1155) were test-posit ...200010854933
the effect of subclinical mycobacterium paratuberculosis infection on days open in michigan, usa, dairy cows.a prospective cohort study design was used to evaluate the impact of subclinical mycobacterium paratuberculosis infection on days open in a sample of michigan dairy herds with a history of cows positive for m. paratuberculosis diagnosed by fecal culture. participating herds were tested and productivity and reproduction records were monitored for 18 months. all cows > or = 24 months old were tested for m. paratuberculosis infection using the elisa and radiometric fecal-culture (rfc) techniques. t ...200010913802
construction and screening of mycobacterium paratuberculosis insertional mutant libraries.mycobacterium paratuberculosis causes johne's disease, a common wasting disease in ruminants. as a first step in studying virulence mechanisms, libraries of random mutants were produced in two m. paratuberculosis strains by using the conditionally replicating shuttle phasmid phae94 which contains the transposon tn5367. two thousand mutants were screened for auxotrophy, carbon source preference, and altered cell wall. genes interrupted by insertion were identified for seven mutants isolated from ...200010763756
prevalence of paratuberculosis (johne's disease) in the belgian cattle population.the national bovine paratuberculosis (ptb) seroprevalence (apparent prevalence) in the belgian cattle population was determined by a serological survey that was conducted from december 1997 to march 1998. in a random sample of herds (n=556, 9.5%), all adult cattle of 24 months of age or older (n=13,317, 0.4%) were tested for the presence of antibodies using a commercially available absorbed elisa test kit. the ptb median within-herd seroprevalence (proportion of detected animals within the serop ...200011118712
first evidence of johne's disease in farmed red deer (cervus elaphus) in belgium.in a deer farm, chronic diarrhoea was seen in a 4-year-old hind. this animal died in poor condition on the farm and johne's disease was suspected. ziehl-neelsen staining of the faeces of this hind were positive for the presence of clumps of small acid-fast bacilli, but faecal cultures remained negative. direct and indirect tests were performed on 24 hinds and stags (yearlings, 2- and 4-year-old animals). the indirect tests performed were serology (mycobacterium paratuberculosis antibody elisa, h ...200011118713
detection of mycobacterium avium subsp. paratuberculosis in milk from clinically affected cows by pcr and culture.milk and faeces samples from cows with clinical symptoms of paratuberculosis were examined for the presence of mycobacterium avium subsp. paratuberculosis (m. paratuberculosis) by culture and pcr. m. paratuberculosis was cultivated in variable numbers from faeces or intestinal mucosa in eight of 11 animals. in milk from five cows (all faeces culture positive), we cultivated a few colonies of m. paratuberculosis (<100 cfu per ml). milk samples from two cows were pcr positive (both animals were fa ...200011118714
paratuberculosis in sheep: an emerging disease in south africa.during a serological survey for ovine paratuberculosis a total of 145934 ovine serum samples from 2019 farms throughout south africa were tested by means of the agid assay. fifty-two infected farms were identified in the western cape and eastern cape provinces. links between infected farms in the two provinces were established. examination of the distribution of infected farms in the western cape indicated a positive correlation between acid soils and occurrence of infection. in an attempt to in ...200011118715
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
the histopathologic diagnosis of subclinical johne's disease in north american bison (bison bison).the morphologic changes of subclinical johne's disease in north american bison (bison bison) are characterized by microgranulomas composed of epithelioid macrophages and individual multinucleate giant cells of langhans'-type occasionally containing individual cytoplasmic acid-fast bacilli compatible with mycobacterium avium paratuberculosis. the microgranulomas are best visualized in the mesenteric lymph nodes of infected subclinical animals. macrophages that can be confused with infection-assoc ...200011118717
binding of bovine growth hormone to. mycobacterium avium ss paratuberculosis.mycobacterium avium ss paratuberculosis causes a chronic progressive enteritis in cattle and other ruminants referred to as johne's disease. it also has been suggested by some as possibly being associated with crohn's disease in humans. in a previous study we observed that incubation of bovine monocytes with recombinant bovine growth hormone (bgh) altered the ingestion and intracellular growth of m. avium ss paratuberculosis in vitro. this led us to investigate whether bgh also has a direct effe ...200010855661
in situ-pcr for the detection of mycobacterium paratuberculosis dna in paraffin-embedded tissues.molecular biological techniques have permitted the rapid and sensitive detection of the mycobacterium paratuberculosis genome in infected tissues, most commonly by polymerase chain reaction amplification of sequences in the is900 dna insertion sequence. the aim of this work was the detection of m. paratuberculosis dna in ovine tissues by in situ-polymerase chain reaction, which is sensitive and localises the signal within the tissue sample. paraffin embedded tissues from three acid-fast positive ...200010968366
quality control and optimized procedure of hybridization capture-pcr for the identification of mycobacterium avium subsp. paratuberculosis in faeces.nucleic acid sequence capture techniques are used to improve both the sensitivity and specificity of pcr for the diagnosis of plant, animal and human diseases. hybridization capture-pcr (hc-pcr) was first reported as a method for the detection of mycobacterium avium subsp. paratuberculosis in 1995 and was successfully trialed on a small number of faecal samples from cattle with johne's disease. a locally optimized hc-pcr method was evaluated on faeces from infected and non-infected animals. howe ...200010970726
dna fingerprinting of australian isolates of mycobacterium avium subsp paratuberculosis using is900 rflp.to evaluate additional restriction enzymes for is900 rflp of mycobacterium avium subsp paratuberculosis and examine the genetic diversity among australian isolates for epidemiological studies of johne's disease.200010860159
evaluation of the accuracy and reproducibility of a practical pcr panel assay for rapid detection and differentiation of mycobacterium avium subspecies.the mycobacterium avium subspecies (mas) include the closely related mas avium and mas paratuberculosis. this study was conducted to evaluate the performance of a pcr panel assay as a diagnostic tool to detect and differentiate mas avium and mas paratuberculosis infection. specific oligonucleotides primers derived from the 16 s rrna (mas) sequence, insertion elements is 901 (mas avium), is 1245 mycobacterium avium complex (mac), is 900 (mas paratuberculosis), and the hspx (mas paratuberculosis) ...200010860713
molecular epidemiology of mycobacterium avium subsp. paratuberculosis: is900 restriction fragment length polymorphism and is1311 polymorphism analyses of isolates from animals and a human in australia.the distribution and prevalence of strains of mycobacterium avium subsp. paratuberculosis were determined among sheep, cattle, and other species with johne's disease in australia. a total of 328 isolates were evaluated from numerous farms in new south wales, victoria, tasmania, and south australia, australia. restriction fragment length polymorphism (rflp) analysis of genomic dna using bsteii and an is900 probe and is1311 polymorphism analysis using pcr and restriction endonuclease analysis (pcr ...200010970365
cytokine secretion by peripheral blood mononuclear cells from cows infected with mycobacterium paratuberculosis.to compare cytokine secretion patterns of peripheral blood mononuclear cells (pbmc) from healthy cows and cows subclinically and clinically infected with mycobacterium paratuberculosis.200010895895
specificity of four serologic assays for mycobacterium avium ss paratuberculosis in llamas and alpacas: a single herd study.an investigation was conducted for mycobacterium avium ss paratuberculosis infections in a research herd of llamas and alpacas. herd culture-negative status was established over a 23-month period by screening any individuals with any signs compatible with paratuberculosis (n = 1), high serology values (n = 8), or other health and research related reasons (n = 24). there were no m. avium ss paratuberculosis isolates from radiometric cultures of multiple tissue and fecal samples from these individ ...200010907864
mycobacterium paratuberculosis heat resistance. 200010792659
alkyl hydroperoxide reductases c and d are major antigens constitutively expressed by mycobacterium avium subsp. paratuberculosis.antigens characteristic for mycobacterium avium subspecies paratuberculosis were identified by crossed immunoelectrophoresis (cie) and by absorbing out cross-reactive antigens by using a polyclonal and polyvalent mycobacterium avium subspecies avium antiserum. two antigens were present in m. avium subsp. paratuberculosis and not detected in mycobacterium avium subsp. avium. they were identified as antigens 17 and 20 in a cie reference system for m. avium subsp. paratuberculosis antigens. purifie ...200010639449
immunohistochemical detection of mycobacterium paratuberculosis in formalin-fixed, paraffin-embedded bovine tissue sections. 200010690778
temporal patterns and quantification of excretion of mycobacterium avium subsp paratuberculosis in sheep with johne's disease.to determine the frequency of excretion of mycobacterium avium subsp paratuberculosis in merino sheep with johne's disease and to quantify excretion in a group of merino sheep.200010736683
biosecurity practices of beef cow-calf producers.to evaluate biosecurity practices of cow-calf producers.200010909456
the use of interleukin-2 receptor expression as a marker of cell-mediated immunity in goats experimentally infected with mycobacterium avium ssp. paratuberculosis.the purpose of the present work was to demonstrate cell-mediated immune response to paratuberculosis in experimentally infected animals, using quantification of interleukin-2 receptor (il-2r) expression on activated lymphocytes by means of in vitro stimulation with mycobacterium avium ssp. paratuberculosis-derived purified protein derivative (ppdp). a whole-blood technique was developed, and optimal conditions for quantification of il-2r expression on caprine lymphocytes, using monoclonal antibo ...200010713335
isolation of mycobacterium avium subsp paratuberculosis from breast milk of crohn's disease patients. 200010763975
effect of three factors in cheese production (ph, salt, and heat) on mycobacterium avium subsp. paratuberculosis viability.low ph and salt are two factors contributing to the inactivation of bacterial pathogens during a 60-day curing period for cheese. the kinetics of inactivation for mycobacterium avium subsp. paratuberculosis strains atcc 19698 and dominic were measured at 20 degrees c under different ph and nacl conditions commonly used in processing cheese. the corresponding d values (decimal reduction times; the time required to kill 1 log(10) concentration of bacteria) were measured. also measured were the d v ...200010742208
use of pooled fecal culture for sensitive and economic detection of mycobacterium avium subsp. paratuberculosis infection in flocks of sheep.ovine johne's disease, or paratuberculosis, occurs in many countries. in australia, surveillance using serology is used as part of a control program, but the testing regime is costly relative to its sensitivity. for this reason, culturing of mycobacterium avium subsp. paratuberculosis in fecal samples pooled from a number of sheep was evaluated. initially, the effect of pooling on the sensitivity of fecal culture was evaluated using samples from 20 sheep with multibacillary paratuberculosis and ...200010878042
a causal role for mycobacterium avium subspecies paratuberculosis in crohn's disease? 200010888725
fibronectin attachment protein homologue mediates fibronectin binding by mycobacterium avium subsp. paratuberculosis.attachment of mycobacterium avium subsp. paratuberculosis to host tissue and penetration of mucosal surfaces are pivotal events in the pathogenesis of johne's disease. fibronectin (fn) binding is required for attachment and internalization of several mycobacteria by epithelial cells in vitro. the objective of this study was to further characterize the fn binding activity of m. avium subsp. paratuberculosis. although the bacteria bound fn poorly at ph above 7, brief acid pretreatment greatly enha ...200111254560
use of long-term vaccination with a killed vaccine to prevent fecal shedding of mycobacterium avium subsp paratuberculosis in dairy herds.to determine whether vaccination with a killed vaccine prevents fecal shedding of mycobacterium avium subsp paratuberculosis, to compare effectiveness of a culture and cull program in vaccinated and nonvaccinated herds, and to compare paratuberculosis-related preventive management in vaccinated and nonvaccinated herds.200111212038
inactivation of mycobacterium paratuberculosis by pulsed electric fields.the influence of treatment temperature and pulsed electric fields (pef) on the viability of mycobacterium paratuberculosis cells suspended in 0.1% (wt/vol) peptone water and in sterilized cow's milk was assessed by direct viable counts and by transmission electron microscopy (tem). pef treatment at 50 degrees c (2,500 pulses at 30 kv/cm) reduced the level of viable m. paratuberculosis cells by approximately 5.3 and 5.9 log(10) cfu/ml in 0.1% peptone water and in cow's milk, respectively, while p ...200111375202
comparison of dna probe test and cultivation methods for detection of mycobacterium avium subsp paratuberculosis in caprine and ovine faeces.to compare a dna probe test with two cultivation methods for the detection of mycobacterium avium subsp paratuberculosis in goat and sheep faeces.200111221569
detection of mycobacterium avium subsp. paratuberculosis in tissue samples by single, fluorescent and nested pcr based on the is900 gene.the aim of this study was to determine if fluorescent pcr could be used instead of nested pcr, for the detection of mycobacterium avium subsp. paratuberculosis (m. paratuberculosis) in clinical specimens, to improve the sensitivity without increasing the risk for cross-contamination. we investigated and compared the sensitivity of single pcr, fluorescent pcr and nested pcr for the detection of is900, an insertion sequence specific for m. paratuberculosis. a previously described extraction method ...200111390109
recovery of mycobacterium avium subsp. paratuberculosis from nematode larvae cultured from the faeces of sheep with johne's disease.a study was conducted to determine whether trichostrongylid nematode larvae become contaminated with mycobacterium avium subsp. paratuberculosis when they develop in the faeces of sheep with johne's disease. nematode larvae were hatched from ova in the faecal samples of affected sheep. larval sheaths were removed and these as well as exsheathed larvae were subjected to radiometric culture for m. paratuberculosis. the organism was recovered from washing water used to prepare the larvae, third sta ...200111390110
[integrated disease control in dairy herds. a case study from the veterinarians' viewpoint].integrated control of bovine virus diarrhoea virus, bovine herpesvirus-1, leptospira interrogans serovar hardjo subtype hardjobovis, mycobacterium avium subsp. paratuberculosis, and salmonella dublin in dairy herds may provide economic benefits superior to those obtained by sequential disease control, because, among other things, it allows optimization of voluntary culling. however, in practice there are no adequate instruments to establish priorities in voluntary culling. therefore, in this stu ...200111392987
immune reactions in cattle after immunization with a mycobacterium paratuberculosis vaccine and implications for the diagnosis of m. paratuberculosis and m. bovis infections.after immunization of four calves with a live modified mycobacterium paratuberculosis vaccine the course of the humoral and cell mediated immune reactions was studied during a 2-year clinical investigation. furthermore, the possibility of shedding of the vaccine strain and the influence of the vaccination on the tuberculin skin test was determined. in addition to standard procedures recently developed diagnostic methods (antibody enzyme-linked immunosorbent assay, interferon-gamma test, polymera ...200111393814
ahpc, ahpd, and a secreted 14-kilodalton antigen from mycobacterium avium subsp. paratuberculosis distinguish between paratuberculosis and bovine tuberculosis in an enzyme-linked immunosorbent assay.sera from cattle naturally infected with mycobacterium avium subsp. paratuberculosis (n = 56) and naturally (n = 4) and experimentally (n = 8) infected with mycobacterium bovis were tested for the presence of antibodies against paratuberculosis antigens. an enzyme-linked immunosorbent assay (elisa) was established based on absorption of m. avium subsp. paratuberculosis antigens on a hyperimmune antiserum against m. avium subsp. avium proteins in order to remove cross-reacting antigens. this abso ...200111427429
mycobacterium avium subsp. paratuberculosis in veterinary medicine.mycobacterium avium subsp. paratuberculosis (basonym m. paratuberculosis) is the etiologic agent of a severe gastroenteritis in ruminants known as johne's disease. economic losses to the cattle industry in the united states are staggering, reaching $1.5 billion annually. a potential pathogenic role in humans in the etiology of crohn's disease is under investigation. in this article, we review the epidemiology, pathogenesis, diagnostics, and disease control measures of this important veterinary p ...200111432810
natural paratuberculosis infection in rabbits in scotland.natural paratuberculosis infection of rabbits (oryctolagus cuniculus) was recently diagnosed in scotland, and an investigation into the pathology of the disease in wild rabbits is reported in this paper. evidence of mycobacterium avium subsp. paratuberculosis (m.a. paratuberculosis) infection was detected in 22% of 110 rabbits; the organism was cultured from 17 of 110 rabbits, and histopathological lesions consistent with m.a. paratuberculosis infection were noted in 18 of 98 rabbits examined. n ...200111437505
intracellular trafficking of mycobacterium avium ss. paratuberculosis in macrophages.the granulomatous enteric lesions of cattle with johne's disease are composed of infected macrophages, and grow by accumulation, re-infection, and expansion of macrophage populations in the intestinal wall. we have examined the growth of bacteria in macrophages to define characteristics of intracellular trafficking for exocytosis, replication, and antigen presentation. using immunocytochemical markers for light, confocal and electron microscopy, we have examined potential pathway tropisms using ...200111449907
subclinical paratuberculosis in goats following experimental infection. an immunological and microbiological study.an experimental oral infection of goats with a caprine isolate of mycobacterium a. subsp. paratuberculosis was used to investigate immunological and bacteriological events during the subclinical phase of infection. seven goats at 5-8 weeks of age were given a bacterial suspension in milk-replacement three times weekly for 9 weeks. six animals were kept as controls. cellular recall responses against m. a. paratuberculosis were analysed by means of a lymphocyte proliferation test, an ifn-gamma ass ...200111457480
characterization of the intracellular survival of mycobacterium avium ssp. paratuberculosis: phagosomal ph and fusogenicity in j774 macrophages compared with other mycobacteria.the phagosomes containing viable pathogenic mycobacteria, such as mycobacterium (m.) tuberculosis and mycobacterium avium ssp. avium (m. avium), are known to be limited in their ability to both acidify and fuse with late (but not early) endocytic organelles. here, we analysed the ph and fusogenicity of phagosomes containing m. avium ssp. paratuberculosis (m. ptb), the causative agent of paratuberculosis in ruminants. using the murine j774 macrophage cell line, we compared viable and heat-killed ...200111488816
incidence of mycobacterium paratuberculosis in raw sheep and goats' milk in england, wales and northern ireland.a blind survey of 104 raw sheep and goats' milk samples (90 goat, 14 sheeps) from bulk tanks on farms throughout england, wales and northern ireland was carried out over a 5-month period (january-may 1998) in order to determine the incidence of mycobacterium paratuberculosis. each milk sample (100 ml) was divided into two 50ml portions. one portion was decontaminated with 0.75% hexadecylpyridinium chloride for 5h before culture on slopes of herrold's egg yolk medium and in bactec radiometric med ...200111230934
[eradication of paratuberculosis in dairy herds: determination of the initial herd prevalence and modelling of prevalence development].a prerequisite for the success of any eradication programme is the accurate determination of the initial herd prevalence as well as a herd-specific prediction of prevalence development. this prerequisite is not currently given for the eradication of paratuberculosis in infected herds. in the work presented a method to predict the initial paratuberculosis prevalence in infected herds is presented; it is based on the formation of two groups (elisa-positive and negative) and the determination of ge ...200111505846
prevalence of antibodies against mycobacterium avium subsp paratuberculosis among beef cow-calf herds.to estimate the prevalence of mycobacterium avium subsp paratuberculosis infection among cows on beef operations in the united states.200111518178
identification of a secreted superoxide dismutase in mycobacterium avium ssp. paratuberculosis.mycobacterium avium ssp. paratuberculosis (m. paratuberculosis), the causative agent of johne's disease, is an important animal pathogen that has also been implicated in human disease. the major proteins expressed by m. paratuberculosis were analyzed by two-dimensional gel electrophoresis, and a superoxide dismutase (sod) was identified from this protein profile. the m. paratuberculosis sod has a molecular mass of 23 kda and an isoelectric point of 6.1. sequence analysis of the corresponding sod ...200111520620
effect of turbulent-flow pasteurization on survival of mycobacterium avium subsp. paratuberculosis added to raw milk.a pilot-scale pasteurizer operating under validated turbulent flow (reynolds number, 11,050) was used to study the heat sensitivity of mycobacterium avium subsp. paratuberculosis added to raw milk. the atcc 19698 type strain, atcc 43015 (linda, human isolate), and three bovine isolates were heated in raw whole milk for 15 s at 63, 66, 69, and 72 degrees c in duplicate trials. no strains survived at 72 degrees c for 15 s; and only one strain survived at 69 degrees c. means of pooled d values (dec ...200111525992
fate of mycobacterium avium subsp. paratuberculosis in swiss hard and semihard cheese manufactured from raw milk.raw milk was artificially contaminated with declumped cells of mycobacterium avium subsp. paratuberculosis at a concentration of 10(4) to 10(5) cfu/ml and was used to manufacture model hard (swiss emmentaler) and semihard (swiss tisliter) cheese. two different strains of m. avium subsp. paratuberculosis were tested, and for each strain, two model hard and semihard cheeses were produced. the survival of m. avium subsp. paratuberculosis cells was monitored over a ripening period of 120 days by pla ...200111526024
experimental paratuberculosis in calves following inoculation with a rabbit isolate of mycobacterium avium subsp. paratuberculosis.the role of wildlife species in the epidemiology of paratuberculosis has been the subject of increased research efforts following the discovery of natural paratuberculosis in free-living rabbits from farms in east scotland. this paper describes the experimental inoculation of young calves with an isolate of mycobacterium avium subsp. paratuberculosis recovered from a free-living rabbit. after a 6-month incubation period, all eight calves inoculated with the rabbit isolate had developed histopath ...200111526132
[current paratuberculosis management by the health department]. 200111544930
comparison of immunomagnetic bead separation-polymerase chain reaction and faecal culture for the detection of mycobacterium avium subsp paratuberculosis in sheep faeces. 200111549050
identification of two mycobacterium avium subspecies paratuberculosis gene products differentially recognised by sera from rabbits immunised with live mycobacteria but not heat-killed mycobacteria.the investigation of environmentally regulated proteins has led to a better understanding of host-pathogen interactions and identified novel vaccine candidate antigens for several bacterial pathogens. in an effort to identify such proteins in mycobacterium avium subsp. paratuberculosis (m. paratuberculosis), a genomic expression library was differentially screened with sera from rabbits that had been immunised with live m. paratuberculosis (alpha-live) as well as sera from rabbits immunised with ...200111549181
identification, cloning and expression of sodc from an alkaline phosphatase gene fusion library of mycobacterium avium subspecies paratuberculosis.the phoa gene technology was used to investigate secreted proteins of the intracellular pathogen mycobacteriumn avium subspecies paratuberculosis. this led to the identification of sodc, a gene which codes for a copper and zinc cofactored superoxide dismutase (cu,znsod) which has been implicated as a virulence factor for some pathogens. the predicted protein possessed a 76% identity with cu,znsod of mycobacterium tuberculosis. to characterize cu,znsod from m. avium subspecies paratuberculosis, t ...200111549243
comparative evaluation of four decontamination protocols for the isolation of mycobacterium avium subsp. paratuberculosis from milk.four chemical decontamination protocols for milk were compared with respect to mean percentage recovery of spiked mycobacterium avium subsp. paratuberculosis, minimum detection limit and ease of application.200111555198
bactericidal effect of chlorine on mycobacterium paratuberculosis in drinking water.one possible route of transmission of mycobacterium paratuberculosis from cattle to humans is via contaminated water supplies. the aim of this work was to determine whether this organism can survive standard water treatment processes.200111555209
innate ifn-gamma production in cattle in response to mpp14, a secreted protein from mycobacterium avium subsp. paratuberculosis.calves experimentally infected with mycobacterium avium subsp. paratuberculosis and uninfected calves were tested for interferon(ifn)-gamma production after stimulation with purified protein derivative from m. avium subsp. paratuberculosis (ppdp) or a secreted 14 kda protein (mpp14) specific for the m. avium-intracellulare-scrofulaceum (mais) complex. several calves in both groups responded strongly up to about 5 months to both antigens. two uninfected calves responded repeatedly, but not always ...200111555395
cytokine gene expression in ileal tissues of cattle infected with mycobacterium paratuberculosis.cytokine gene expression in ileal tissues of cattle infected with mycobacterium paratuberculosis was evaluated. the effects of infection with m. paratuberculosis on cytokine production may influence immune regulation at the site of colonization, resulting in the chronic inflammatory state associated with the latter stages of this disease. ileal samples were obtained at necropsy from noninfected control cows (n=8) and clinically infected cows (n=7) and processed for immunohistochemistry and in si ...200111557295
heat inactivation data for mycobacterium avium subsp. paratuberculosis: implications for interpretation.we discuss several factors that are critical for heat inactivation experiments and which should be taken into account for future research.200111576307
t cell-dependent inducible nitric oxide synthase production and ultrastructural morphology in balb/c mice infected with mycobacterium avium subspecies paratuberculosis.euthymic balb/c and athymic nude balb/c mice aged 3-8 days were infected intraperitoneally with mycobacterium avium subspecies paratuberculosis (atcc strain 19698). after euthanasia at 5 months post-inoculation, hepatic granulomas were evaluated by morphometric analysis of digital images captured from light microscopy sections, by electron microscopy and by immunohistochemical methods. euthymic mice differed from athymic mice in that (1) their hepatic granulomas were smaller, contained fewer bac ...200111578129
an enzyme-linked immunosorbent assay using immonoaffinity-purified antigen in the diagnosis of caprine paratuberculosis and its comparison with conventional elisas.an enzyme-linked immunosorbent assay (apa-elisa) using an immunoaffinity-purified antigen was developed and compared with the unabsorbed and absorbed elisa procedures, using a crude antigenic preparation, for its efficacy in detecting antibodies in goat sera against mycobacterium ovium paratuberculosis. serum samples from 89 goats belonging to three different flocks, two with a history and evidence of paratuberculosis and one without it, were subjected to each elisa, which had been standardized ...200111583377
the esat-6 gene cluster of mycobacterium tuberculosis and other high g+c gram-positive bacteria.the genome of mycobacterium tuberculosis h37rv has five copies of a cluster of genes known as the esat-6 loci. these clusters contain members of the cfp-10 (lhp) and esat-6 (esat-6) gene families (encoding secreted t-cell antigens that lack detectable secretion signals) as well as genes encoding secreted, cell-wall-associated subtilisin-like serine proteases, putative abc transporters, atp-binding proteins and other membrane-associated proteins. these membrane-associated and energy-providing pro ...200111597336
[modelling of prevalence development in a paratuberculosis control program in a dairy herd].a modelling approach to calculate the success of a paratuberculosis control programme in dairy herds is presented. the essential parameters of the model are the prevalence at the beginning of the programme, diagnostic sensitivity and specificity of the tests used, discipline in culling test-positive animals, turnover in the herd, percentage of replacement with own stock and paratuberculosis prevalence in animals bought into the herd from outside, and a general hygiene-based factor. diagnostic me ...200111599437
dietary effects on the microbiological safety of food.the high mortality rate associated with human infections caused by escherichia coli strains of the serotype o157:h7 has brought to public attention the importance of ruminants as reservoirs of food-borne pathogens. in addition to established examples such as salmonella, campylobacter and listeria, recent evidence is emerging of the role of food in the transmission of helicobacter pylori and mycobacterium paratuberculosis. food-borne pathogens harboured by ruminants are spread through shedding in ...200111681640
the effect of subclinical mycobacterium paratuberculosis infection on milk production in michigan dairy cows.the objective of this study was to determine the effect of subclinical mycobacterium paratuberculosis infection on mature equivalent milk, protein, and fat production in a sample of michigan dairy herds with a history of cows positive for m. paratuberculosis diagnosed by fecal culture. a prospective two-group cohort study was conducted. participating herds were tested, and productivity and reproduction records were monitored for 18 mo. all cows aged 24 mo and greater were tested for m. paratuber ...200111699450
protagonist. mycobacterium avium subspecies paratuberculosis is a cause of crohn's disease. 200111709506
antagonist. mycobacterium avium subspecies paratuberculosis is a cause of crohn's disease. 200111709507
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