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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Infectious Bacterial Diseases Research » Research » Publications at this Location » Publication #311428

Title: Fecal volatile organic compound profiles from white-tailed deer (Odocoileus virginianus) as indicators of Mycobacterium bovis exposure or Mycobacterium bovis bacille Calmette-Guerin (BCG) vaccination

Author
item STAHL, RANDAL - Animal And Plant Health Inspection Service (APHIS)
item ELLIS, CHRISTINE - Animal And Plant Health Inspection Service (APHIS)
item NOL, PAULINE - Animal And Plant Health Inspection Service (APHIS)
item Waters, Wade
item Palmer, Mitchell
item VERCAUTEREN, KURT - Animal And Plant Health Inspection Service (APHIS)

Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2015
Publication Date: 6/10/2015
Citation: Stahl, R.S., Ellis, C.K., Nol, P., Waters, W.R., Palmer, M.V., Vercauteren, K. 2015. Fecal volatile organic compound profiles from white-tailed deer (Odocoileus virginianus) as indicators of Mycobacterium bovis exposure or Mycobacterium bovis bacille Calmette-Guerin (BCG) vaccination. PLoS One. 10(6):e0129740. doi: 10.1371/journal.pone.0129740.

Interpretive Summary: Despite highly successful eradication efforts in several countries, tuberculosis of cattle remains a serious health concern worldwide. In addition, recent outbreaks of tuberculosis in Michigan, Minnesota, California, Washington, Texas, Nebraska, Indiana, Colorado, and New Mexico demonstrate that the disease is far from eliminated from the United States. Control of bovine tuberculosis is hindered by the presence of wildlife reservoirs, such as white-tailed deer in Michigan, continued importation of tuberculosis-infected cattle from Mexico, and failure of current testing strategies to detect infected animals. Improved techniques are needed to detect tuberculosis-infected cattle and deer. In the present study, a novel technique to detect signatures of tuberculosis infection in fecal samples was developed. These findings demonstrate the feasibility for development of novel and simple tests to detect bovine tuberculosis. Knowledge obtained from this study will enable more accurate detection of tuberculosis in deer, thereby, enhancing the tuberculosis eradication program.

Technical Abstract: White-tailed deer (Odocoileus virginianus) serve as a reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and can be a source of infection in cattle. Vaccination with M. bovis bacille Calmette-Guerin (BCG) is being considered for management of bovine tuberculosis in deer. Presently, no method exists to noninvasively monitor the presence of bovine tuberculosis in deer. In this study, volatile organic compound profiles of BCG-vaccinated and unvaccinated deer, before and after infection with M. bovis strain 95-1315, were generated using solid phase microextraction fiber head-space sampling over suspended fecal pellets with analysis by gas chromatography/mass spectrometry. Chromatograms were processed using XCMSOnline to characterize ion variation among treatment groups. The principal component scores resulting from significant (alpha= 0.05) ion responses were used to build linear discriminant analysis models. The sensitivity and specificity of these models were used to evaluate the feasibility of using this analytical approach to distinguish within group comparisons between pre- and post-exposure: unvaccinated male or female deer, vaccinated male deer, and the unvaccinated deer data pooled. Seventeen compounds were identified in this analysis. The peak areas for these compounds were used to build a linear discriminant classification model based on Principal Component Analysis scores to evaluate the feasibility of discriminating between fecal samples from M. bovis challenged deer, irrespective of vaccination status. The model best representing the data had a sensitivity of 78.6% and a specificity of 91.4%. The fecal head-space sampling approach presented in this pilot study provides a non-invasive method to discriminate between M. bovis exposed deer and BCG-vaccinated deer. Additionally, the technique may prove invaluable for BCG efficacy studies with free-ranging deer as well as for use as a non-invasive monitoring system for the detection of tuberculosis captive deer.