Progress 03/01/15 to 02/29/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Through peer-reviewed jounral publications and conference proceedings. What do you plan to do during the next reporting period to accomplish the goals?During the next period, we will first test 180 serum samples from cows in well-characterized infected and non-infected groups with Mtb protein arrays. Bioinformatic and statistical analysis tools will be applied to select the candidates for MAP protein and the new MAP recombinant proteins will be expressed and added to MAP protein array. Next,we will test same serum samples on expanded MAP protein arrays to identify validated MAP antigens that enable the development of the next generation of sensitive and specific diagnosis assays for detection of early MAP infection. The results will be submitted for publication in peer-reviewed journals as well as at major international conferences and proceedings.
Impacts
What was accomplished under these goals?
A slow-growing bacterium, Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease (JD) in cattle. JD has a high prevalence rate and results in considerable adverse impact on animal health and productivity in the US. Progress in controlling the spread of infection has been impeded by the lack of reliable diagnostic tests that can identify animals early in the infection process and help break the transmission chain. The knowledge and resources gained from our proposed investigations will enable the construction of a rational framework for the development and validation of future generations of specific and sensitive immunodiagnostic assays, and enhance animal health and productivity through better control of JD. Two experiments were performedduring this reporting period. First, we studied thedynamics of immune response to MAP proteins in experimentally infected animals; and second, we testedthe feasibility of employing a previously describedMycobacterium tuberculosis (Mtb) protein array forantigen discovery in JD. We tested serological reactivity to MAP protein arrays in 10 experimentally MAP-infected goats as compared with 10 non-infected goats as negative control at 7 time points (0, 2, 4, 6, 8, 10, 12 months post infection. Sero-reactivity of un-infected cows (Negative), MAP-infected cows at clinical stage (Clinical) and MAP-infected cows at sub-clinical stage (Sub-clinical) were compared on Mtb arrays for the above groups as well as on MAP protein arrays. Intensities from each protein spot scan were collected and normalized (both vsn normalization method or log2-transformation methods) and analyzed for all seven time points in as well as for the top 30 antigens from ~4,000 protein spots in clinical and sub-clinical groups and analyzed using parametric (Student's T test) and non-parametric tests (Wilcoxon's tank sum test and AUC estimation) for between-group comparisons. The studies reveal eight candidate proteins that are detected as early as 2 months post initial infection with MAP, which is considerably sooner than the detection of fecal MAP shedding. This preliminary result suggests that the protein microarray approach may enable the identification of antigens that are sero-reactive even during the early pre-shedding stages of infection. The studies also revealed that the application of the Mtb protein array will greatly expand the number of testable MAP proteins for antigen discovery and may lead to novel diagnostic antigens for JD.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Li, L., Katani, R., Schilling, M., Kapur, V., Molecular Epidemiology of Mycobacterium avium subsp. paratuberculosis on Dairy Farms. Annu Rev Anim Biosci, 2016. 4: p. 155-76.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2016
Citation:
Bannantine, J. P., Campo, J., Li, L, Randall, A., Pablo, J., Praul, C. A., Raygoza Garay, J. A., Stabel, J., and Kapur, V. Application of the Mycobacterium tuberculosis protein array to Antigen discovery in Johnes disease. 2016. 2016
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2016
Citation:
Li, L, Bannantine, J. P., Praul, C. A., Raygoza Garay, J. A., Hines II, M. E., Katani, R., Mwangi, M., Kapur, V. (2016). Discovery of sero-reactive antigens in Mycobacterium avium subsp. paratuberculosis with protein microarrays. Poster presentation at 13th International Colloquium on Paratuberculosis, June 20-24, Nantes, France.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2016
Citation:
Li, L, Bannantine, J. P., Praul, C. A., Raygoza Garay, J. A., Hines II, M. E., Katani, R., Kapur, V. (2016). Application of protein microarrays for the identification of sero-reactive antigens in Mycobacterium avium subsp. paratuberculosis. Poster presentation at American Society for Microbiology (ASM) Microbe, June 16-20, Boston, USA
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