Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 4/10/2008
Publication Date: 6/2/2008
Citation: Cook, K.L., Britt, J., Rothrock Jr, M.J., Sorrell, J. 2008. Survival of Mycobacterium avium subsp. paratuberculosis in Biofilms on Livestock Watering Trough Materials. American Society for Microbiology Annual Meeting. Interpretive Summary:
Technical Abstract: Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) is the causative agent of Johne’s disease, a chronic enteric infection that affects ruminants. Despite the ubiquitous occurrence of Mycobacterium sp. in nature and the fact that Johne’s disease has been reported worldwide, little research has been done to assess its survival in agricultural environments. The goal of this study was to evaluate the ability of M. paratuberculosis to become established and persist in biofilms on coupons composed of common livestock watering trough materials. M. paratuberculosis was inoculated into triplicate containers with 32L of trough water and either concrete, plastic, galvanized or stainless steel coupons. One set of samples was treated with chlorine (5.7 ppm final concentration) every 7 - 28 days and the other set was left untreated. The concentration of M. paratuberculosis was determined by targeting the IS900 sequence in DNA extracted from samples by using quantitative, real-time PCR. The average concentration of M. paratuberculosis at the beginning of the experiment was 4.6 ± 2.8 X 104 cells mL-1 water or 1.6 ± 1.3 X 105 cells cm-2 coupon. M. paratuberculosis could still be detected on coupons of all materials after 149 days of incubation. The concentration of M. paratuberculosis was lowest on stainless steel (9.3 ± 6.2 X 101 cells/cm2) and highest on concrete (1.9 ± 1.1 X 104 cells/cm2) coupons. Chlorine had the greatest affect on biofilms present on concrete (cell concentrations were 90% lower for chlorine-treated than for non-chlorine treated biofilms). Biofilms on galvanized and stainless steel coupons were lower in chlorine-treated samples taken between days 35 and 70 (between 60% and 99% lower), but these differences disappeared thereafter; chlorine addition had no affect on biofilms on plastic coupons. These results suggest that M. paratuberculosis survives well (over 149 days) in biofilms present on different trough materials. Trough material composition influenced the survival of M. paratuberculosis with the lowest survival exhibited on stainless steel, followed by plastic, galvanized steel and concrete.