Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “paratuberculosis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed2005

Mycobacterium avium subsp. paratuberculosis from free-ranging deer and rabbits surrounding Minnesota dairy herds.

The objectives of this study were to estimate the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) among deer and rabbits surrounding infected and noninfected Minnesota dairy farms using fecal culture, and to describe the frequency that farm management practices were used that could potentially lead to transmission of infection between these species. Fecal samples from cows and the cow environment were collected from 108 Minnesota dairy herds, and fecal pellets from free-ranging white-tailed deer and eastern cottontail rabbits were collected from locations surrounding 114 farms; all samples were tested using bacterial culture. In addition, a questionnaire was administered to 114 herd owners. Sixty-two percent of the dairy herds had at least 1 positive fecal pool or environmental sample. A total of 218 rabbit samples were collected from 90% of the herds, and 309 deer samples were collected from 47% of the herds. On 2 (4%) of the farms sampled, 1 deer fecal sample was MAP positive. Both farms had samples from the cow fecal pool and cow environment that were positive by culture. On 2 (2%) other farms, 1 rabbit fecal sample was positive by culture to MAP, with one of these farms having positive cow fecal pools and cow environmental samples. Pasture was used on 79% of the study farms as a grazing area for cattle, mainly for dry cows (75%) and bred or prebred heifers (87%). Of the 114 farms, 88 (77%) provided access to drylot for their cattle, mainly for milking cows (77/88; 88%) and bred heifers (87%). Of all study farms, 90 (79%) used some solid manure broadcasting on their crop fields. Of all 114 farms, the estimated probability of daily physical contact between cattle manure and deer or rabbits was 20% and 25%, respectively. Possible contact between cattle manure and deer or rabbits was estimated to occur primarily from March through December. The frequency of pasture or drylot use and manure spreading on crop fields may be important risk factors for transmission of MAP among dairy cattle, deer, and rabbits. Although the MAP prevalence among rabbits and deer is low, their role as MAP reservoirs should be considered.

Animal Husbandry↗
PubMed2005

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.

Animals↗
PubMed2005

Development of improved method for isolation of Mycobacterium avium subsp. paratuberculosis from bulk tank milk: effect of age of milk, centrifugation, and decontamination.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease in cattle and it has been suggested that this organism may be associated with Crohn's disease in humans. Cows at the advanced stage of the disease shed this organism into both their milk and feces. The objective of this study was to develop a more efficient procedure for isolating MAP from bulk tank raw milk. Bulk tank raw milk (50 mL) samples 3 to 13 d old after collection without spiking were investigated to evaluate the effects of milk age on the efficacy of decontamination. Milk samples, 2 to 3 d old, were seeded with MAP at levels of 50 to 200 colony forming units/mL in experiments involving factorial design to evaluate 1) the effects of different decontaminating reagents and decontamination procedures on recovery of MAP, and 2) partition MAP in milk fractions after centrifugation in raw milk. Decontamination in 20 mL of 0.75% hexadecylpyridinium chloride (HPC) at room temperature (22 degrees C) for 2 to 5 h, with shaking, at intervals was found to be the most effective procedure for decontaminating milk 2 to 3 d old. Prolonged exposure to decontaminants, additional incubations in antibiotics, or at higher temperature (37 degrees C) significantly reduced recovery of live MAP. Enhanced growth of microbial contaminants was noticed in samples decontaminated overnight at room temperature compared to those decontaminated for 2 to 5 h. Decontamination of 6 d old milk samples required extra incubation in antibiotic brew. Decontamination of milk samples that are 8 d and older was not effective in removing microbial contaminants. The MAP cells preferentially partitioned into the cream fraction after centrifugation, and combining the milk cream and pellet fractions enhanced recovery of MAP. A recovery rate of 16.6% was estimated with the use of our improved protocol.

Animals↗
PubMed2005

[Observations on the control and eradication of paratuberculosis in dairy herds].

Johne's disease is widely seen in dairy herds in Germany. Estimates based primarily on epidemiological surveys in neighbouring states assume that 5 to 15 % of German herds are infected. In the past three years several authors have reported that the causative agent of Johne's disease, Mycobacterium avium subspecies paratuberculosis (MAP), is found ubiquitously in the environment and can be isolated from a number of different animals, including non ruminants. These results imply that MAP should be considered an environmental pathogen. Based on this assumption a concept for control and eradication of Johne's disease is presented aiming at minimizing the future spread of disease and reducing environmental contamination with the pathogen at low costs. The concept includes the classification of herds based on an bulk milk ELISA followed by a robot-compatible bulk milk PCR in ELISA-positive herds only. Due to the comparatively low costs combined with the high specificity of the approach a detection of heavily infected herds ("tip of the iceberg") all over the country would be possible; based on the eradication of strong shedders in these herds the input of MAP into the environment would be reduced considerably.

Animals↗
PubMed2006

Seroprevalences of antibodies against bovine leukemia virus, bovine viral diarrhea virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in beef and dairy cattle in Manitoba.

Of 1204 dairy cows and 1425 beef cows sampled, 60.8% and 10.3% were seropositive for Bovine leukemia virus, 4.5% and 1.7% were seropositive for Mycobacterium avium subspecies paratuberculosis, and 8.3% and 9.1% were seropositive for Neospora caninum, respectively, while 28.1% of dairy herds had unvaccinated animals with titres > or = 1:64 for Bovine viral diarrhea virus.

Animals↗
PubMed2006

Seroprevalence of Mycobacterium avium subspecies paratuberculosis, Neospora caninum, Bovine leukemia virus, and Bovine viral diarrhea virus infection among dairy cattle and herds in Alberta and agroecological risk factors associated with seropositivity.

A province-wide, cross-sectional seroprevalence and agroecological risk factor study of Mycobacterium avium subspecies paratuberculosis (MAP), Neospora caninum (NC), Bovine leukemia virus (BLV), and Bovine viral diarrhea virus (BVDv) genotypes 1 and 2 (BVDv1 and BVDv2) infection in dairy cattle herds in Alberta was conducted. Among adults, the seroprevalence of MAP, NC, and BLV was 9.1%, 18.5%, and 26.9%, respectively. For MAP, based on a herd test cutpoint of 2 or more seropositive cows, 58.8% of herds were infected. Herd-level seroprevalence for NC and BLV was 98.7% and 86.7%, respectively, based on a herd-test cutpoint of 1 seropositive cow. Among unvaccinated dairy heifers, the seroprevalence for BVDv1 and BVDv2 infection was 28.4% and 8.9%, respectively, while herd-level infection was 53.4% and 19.7%. Seroprevalence for MAP varied moderately by agroecological region, whereas that for NC, BLV, and BVDv1 and BVDv2 did not. For MAP, aridity and soil pH (correlated features of the region) were also important.

Animals↗
PubMed1995

Solid-phase hybridization capture of low-abundance target DNA sequences: application to the polymerase chain reaction detection of Mycobacterium paratuberculosis and Mycobacterium avium subsp. silvaticum.

Polymerase chain reaction (PCR) has been widely applied to the detection of microorganisms. Overall sensitivity of PCR tests may be substantially reduced due to a large excess of nontarget DNA and inhibitory substances in the sample. We used a 5'-biotinylated 513-bp probe from the 3' region of the IS 900 element specific for Mycobacterium paratuberculosis (Mptb) to capture target Mptb DNA from crude sample DNA extracts. Captured target DNA was separated using streptavidin-coated magnetic particles (Dynal). Since the IS 900 element shares homology over this region with IS 902 in Mycobacterium avium subsp. silvaticum (Mavs), target DNA from this other pathogen was also retained. Highly specific PCR for the detection of either organism directed to the 5' regions of IS 900 or IS 902 was then performed directly on the solid phase. Hybridization capture of target DNA using sequence adjacent to the desired specific PCR site applied to Mptb increased overall sensitivity of detection in tissue and fecal extracts 10- to 100-fold. False positives due to contamination artifact were substantially excluded since the capture probe did not retain amplicons from the detection PCR. Development of the method to involve covalent 5' immobilization of capture probes on heat-resistant polymers should, in the future, provide a simple system with broad potential applications.

Animals↗
PubMed1991

Antibody reactivities of Mycobacterium paratuberculosis infected sheep as analyzed by enzyme-linked immunosorbent assay and western blotting.

Antibody reactivities in sera from Mycobacterium paratuberculosis (M. ptb) infected and vaccinated sheep were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western (immuno)blotting using a sonicate antigen from M. ptb. Both methods allowed good differentiation between infected/vaccinated animals and noninfected controls. Removal of nonspecific crossreactive antibodies by absorption with a M. phlei sonicate antigen coupled to Sepharose reduced ELISA reactivities of positive sera by 50% and those of noninfected serum by 85%. Immunoblotting analysis revealed that reduction by M. phlei absorption was due to lower reactivities of M. ptb antigens in the range of 30 to 45 kDa. However, one protein with a molecular mass of approx. 27 kDa seemed to be specific for M. ptb since it reacted similarly with nonabsorbed and absorbed serum but not with antibodies which were eluted from M. phlei-Sepharose after absorption. Our findings indicate that M. ptb and M. phlei share a number of common antigens of potential pathogenic importance and that only a smaller part of proteins (i.e. the 27 kDa protein) might be specific for M. ptb.

Animals↗
PubMed1992

Molecular cloning and characterization of Mycobacterium paratuberculosis promoters in Escherichia coli.

DNA fragments from Mycobacterium paratuberculosis were cloned in the promoter probe plasmid pKO1. Of 957 recombinant DNA clones, 24 induced synthesis of galactokinase (the reporter gene) when these plasmids were transformed into an Escherichia coli strain deficient for the enzyme. A DNA insert from one putative promoter-containing plasmid, designated pAG5, was sequenced and shown to contain, a characteristic RNA polymerase binding site, a probable ribosomal binding site and a putative open reading frame.

Amino Acid Sequence↗
PubMed1990

Immunohistochemical study of bovine lymph nodes with antibodies against S100 protein subunits: comparison between lymph nodes of healthy and Mycobacterium paratuberculosis-infected cattle.

Using immunohistochemistry, the differential distribution of the alpha subunit (S100 alpha) and beta subunit (S100 beta) of S100 protein was studied in mesenteric lymph nodes from normal or Mycobacterium paratuberculosis-infected cattle. In epithelioid cell granulomas, S100 alpha-positive epithelioid cells and some giant cells were scattered among S100 alpha-negative cells, which were predominant. The S100 beta-positive and -negative cells contained acid-fast bacilli. The presence of S100 beta-positive cells was not demonstrated in the granulomas. In normal component cells in the lymph nodes, follicular dendritic cells in the germinal centres and endothelium of lymphatic sinus and lymph vessels were positive for S100 alpha. S100 beta was positive only in the endothelial cells of blood vessels. Results shown in the present paper are discussed in light of results obtained in other work on human tissues using the same sources of antibodies.

Animals↗
PubMed1992

Mycobacterium paratuberculosis binds fibronectin.

Fibronectin, an adhesive glycoprotein which is present in plasma and on many host cell surfaces of many host organisms, binds to certain bacterial pathogens. This study demonstrates the ability of Mycobacterium paratuberculosis (M.ptb) to interact with 125I-labelled fibronectin purified from bovine and ovine plasma. Two M.ptb strains were tested: a clinical isolate and a commercially available vaccine strain. Both strains showed significant fibronectin-binding activities of 22 and 41%, respectively, whereas non-pathogenic M.phlei had almost no affinity for fibronectin. Binding activities were similar for ovine and bovine fibronectin. We found that fibronectin binding by M.ptb was (1) time-dependent, reaching saturation within 90 min, (2) specific, since it was inhibited by an excess of unlabelled fibronectin but not by albumin, (3) saturable, with an apparent dissociation constant of 1.25 x 10(-9) M and a maximal number of 1,600 binding sites per bacterium, and (4) sensitive to detergents, proteases and heat treatments, indicating the protein nature of the responsible binding component(s). Scatchard plot analysis gave a straight line suggesting the presence of a single type of fibronectin receptor on M.ptb.

Animals↗
PubMed2026

Matching genomic evidence to claims about Mycobacterium avium subsp. paratuberculosis: Host association, host adaptation, mechanism, and virulence.

Whole-genome sequencing (WGS) permits high-resolution comparison of Mycobacterium avium subsp. paratuberculosis (MAP) isolates and pangenome analysis. Combined with animal-movement data, WGS can support transmission inference, but resolution alone does not establish the biological meaning of genomic variation. This focused narrative review applies a two-dimensional framework to purposively selected MAP studies, separating claim targets from support profiles. Claim targets include lineage identity, host-source or lineage characterization, host association, transmission, candidate genomic features, measured bacterial or host-cell phenotypes, natural-host infection fitness, disease or damage, shedding, and control outcomes. Depending on the claim, evidence operations may include characterization, context-aware comparative inference, direct endpoint ascertainment, and controlled feature perturbation; these are non-ordinal and may co-occur. On-target attribution, independent replication, and transportability are reported separately. The claim, not the study, is the unit of assessment. Typing markers support isolate or lineage discrimination, whereas phylogenomics supports evolutionary inference; neither alone establishes host adaptation. Pangenome comparisons and microbial genome-wide association studies nominate candidate features rather than establish adaptation. Cell-envelope and iron-associated studies support specified biochemical, transcriptional, or physiological phenotypes under defined conditions, while macrophage and calf models support only the endpoints measured. Annotated sequence variation alone nominates pathogenicity hypotheses. Across the illustrative studies selected here, MAP genomics most directly supported lineage classification, candidate discovery, measured bacterial phenotypes, bounded transmission inference, and natural-host infection-fitness claims. Claims about adaptation, mechanism, virulence, or control require endpoints and comparisons matched to the stated claim and model; feature-specific causal claims additionally require evidence linking the bacterial feature to the measured endpoint.

Claim boundaries↗
PubMed2004

Evaluation of four DNA extraction methods for the detection of Mycobacterium avium subsp. paratuberculosis by polymerase chain reaction.

Polymerase chain reaction (PCR) has been widely used due to its high specificity, sensitivity, and rapid turn-around time. However, inhibitory factors may be co-extracted with the target nucleic acid that will hinder the performance of PCR. In this study, DNA extraction methods for Mycobacterium avium subsp. paratuberculosis were evaluated including rapid lysis, organic extraction, silica-based and magnetic particle-based (MagaZorb) technologies on bacterial cells, and spiked bovine feces. Efficiency of the extraction was determined by PCR end point titration with primers targeting the insertion sequence, IS900. Results of the end point titrations are identical for bacterial cells and spiked feces. Inhibition was observed in PCR with DNA isolated from spiked feces, and a 1/100 dilution was able to alleviate this problem with DNA extracted by MagaZorb. A 1/1000 dilution was required for the other three methods. MagaZorb proved to be more efficient at removing inhibitory factors and required the least labor and completion time. Further evaluation is required for its utilization in other clinical specimens.

Base Sequence↗
PubMed2005

Development and evaluation of a Mycobacterium avium subspecies paratuberculosis (MAP) specific multiplex PCR assay.

There are specificity questions inherent in most of the current PCR systems that amplify the MAP IS900 sequence as an indicator for Mycobacterium avium subspecies paratuberculosis (MAP) presence due to false positives associated with IS900-like sequences that exists in other Mycobacterium species besides MAP. We developed a multiplex PCR system designed to enhance specificity for MAP detection in a single PCR reaction. This PCR assay co-amplifies the mycobacterium species 16S rRNA gene, MAP IS900 and f57 sequences. The assay incorporates an internal PCR amplification control (IC) template system enabling PCR amplification conditions to be assessed in each reaction. The assay's specificity was confirmed by testing 10 isolates of MAP and 59 isolates of other bacterial species. In parallel we also applied on the same samples, one of the established nested PCR systems that targets only the IS900 sequence. The multiplex PCR assay was highly specific for MAP, the nested PCR system was also positive with several other mycobacterium species. In this context, we report for the first time false positive IS900 PCR signals in Mycobacterium chelonae, Mycobacterium terrae and Mycobacterium xenopi strains associated with one of the established PCR systems widely used for MAP detection. Finally, the potential application of this multiplex PCR system in milk analysis is demonstrated through analysis of raw milk samples artificially contaminated with MAP.

Animals↗
PubMed2005

Detection of Mycobacterium avium subspecies paratuberculosis in free-ranging bison (Bison bison) by PCR.

Bacterial culture is the 'gold standard' for detecting Mycobacterium avium subspecies paratuberculosis (MAP) infection, but is time consuming, laborious, and recovery of organism varies with species of animal tested. PCR has been used for detection of MAP DNA in feces and tissues. We used PCR to detect MAP DNA isolated from tissues from 25 free-ranging North American bison (Bison bison), each with clinical signs compatible with Johne's disease. We report the performance of PCR to detect MAP DNA in both frozen and paraffin-embedded ileum, jejunum, and ileocecal lymph node samples collected at the time of slaughter. Specific oligonucleotide primers for PCR amplification were derived from 16S rRNA sequence M. avium subspecies (MAs) and insertion elements IS1245 (MAs avium), IS901 (MAs avium), IS900 (MAP), and hspX (MAP). Genomic DNA samples were prepared three different ways; crude DNA from frozen tissues, crude DNA from paraffin-embedded tissues, and purified DNA from paraffin-embedded tissues. An animal was considered infected if MAP DNA was detected in at least two separate tissues using the IS900 primer set. Using these criteria, 25 of 25 bison tested were positive for MAP. The data indicate that these free-ranging bison have been infected by MAP.

Animals↗
PubMed2006

Detection of Mycobacterium avium subspecies paratuberculosis genetic components in retail cheese curds purchased in Wisconsin and Minnesota by PCR.

Research has been focused on the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in pasteurized milk; however, pasteurized milk is a key ingredient in a variety of food products. Therefore, MAP contamination in milk-derived products must be investigated. We undertook a six-month study to investigate the presence of viable MAP and MAP genetic components in cheese curds purchased from retail outlets in the northern and southern regions of Wisconsin and Minnesota. A total of 98 retail cheese curd samples were tested for MAP by PCR prescreen, culture on Herrold's egg yolk agar slants with mycobactin J and amphoteracin B, naladixic acid, and vancomycin, and slant rinse PCR using IS900 and hspX primer sets. Although no viable MAP were able to be cultured, 5% of the samples were PCR positive with both the IS900 and hspX primer sets (MAP-specific DNA) when prescreened and 1% of the samples were PCR positive with both the IS900 and hspX primer sets when culture slants were rinsed and tested.

Animals↗
PubMed2005

Factor analysis of a Johne's disease risk assessment questionnaire with evaluation of factor scores and a subset of original questions as predictors of observed clinical paratuberculosis.

Factor analysis was used to examine the interrelationships among 38 variables collected as part of a Johne's disease risk assessment questionnaire completed in 2002 on 815 U.S. dairy operations. Eleven factors were extracted, accounting for two-thirds of the variance encountered in the original variables. Responses to many of the risk assessment questions were closely related. Standardized scores on the 11 factors were calculated for operations providing complete information, and were evaluated as predictors in a model-based logistic regression analysis with the outcome being whether operations had observed one or more cows with clinical signs suggestive of paratuberculosis during the previous year. A logistic regression model was also used to evaluate the predictive ability of a reduced subset of approximately one-third of the original variables that was selected to represent the derived factors. The performance of both sets of predictors was comparable with respect to goodness-of-fit and predictive ability. In conclusion, the length of the current risk assessment instrument could be reduced considerably without a substantial loss of information by removing or combining questions that are strongly correlated.

Animals↗