Submitted to: American Society for Microbiology Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/20/2005
Publication Date: 9/30/2005
Citation: Cook, K.L. 2005. Detection of mycobacterium avium subsp. paratuberculosis (map) in the environment. American Society for Microbiology Branch Meeting. Interpretive Summary:
Technical Abstract: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s disease, a chronic, enteric infection that is passed from adults to calves via the fecal-oral route. MAP has become the focus of unwanted attention due to its increased prevalence and the economic impact resulting from decreased milk production and the need to replace culled animals. MAP awareness has also risen due to its possible association with Crohn’s disease in humans. Johne’s disease has been detected on the agricultural research farm at Western Kentucky University, and although eradication plans have been in place for the past 4 years, there has been no reduction in the number of clinical cases. The goal of this study was to evaluate the feasibility of detecting MAP in environmental samples as opposed to testing manure samples taken from cattle. If shown to accurately predict the presence of MAP, detection of MAP in the environment would decrease the time and resources spent on taking fecal and blood samples from livestock. A quantitative, real-time PCR assay was developed to target the IS900 insertion sequence, a sequence specific for MAP. Molecular analysis was conducted on DNA extracted from fecal samples taken from dairy livestock and environmental samples taken from areas on the farm that are frequented by cattle (e.g. cattle alleyways, barns, storage facilities). Environmental samples from areas most frequented by livestock had the highest concentration of MAP (1.2 X 104 to 1.2 X 105 copies gram-1 sample). Less frequented or areas cleaned on a regular basis to eliminate MAP (e.g., the birthing stall) had lower concentrations of MAP (2.3 X 103 to 3.6 X 103 copies gram-1 sample). Results to date suggest that molecular analysis of environmental sources of MAP should provide a reliable indicator of the presence of the organism on the farm site.