Location: Infectious Bacterial Diseases ResearchTitle: An eco-friendly decontaminant to kill Mycobacterium avium subsp. paratuberculosis
Submitted to: Journal of Microbiological Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2020
Publication Date: 9/1/2020
Citation: Stabel, J.R., Turner, A.M., Walker, M.E. 2020. An eco-friendly decontaminant to kill Mycobacterium avium subsp. paratuberculosis. Journal of Microbiological Methods. 176. https://doi.org/10.1016/j.mimet.2020.106001.
Interpretive Summary: Johne's disease is a chronic, debilitating intestinal disorder in cattle, sheep and wild ruminants, characterized by diarrhea, weight loss and death. Animals usually become infected as neonates via ingestion of feces or milk containing the causative bacteria. However, clinical signs of disease may not present themselves until the animals reach 3 to 5 years of age or even older. During this time the animal is infected and may be shedding the organism in its feces without demonstrating any clinical signs of disease. The ability of producers to control the spread of the organism on-farm is critical to halting the cycle of infection. One method is to use disinfectants in the maternity pen to kill any bacteria that may be present. In addition to farm use, we must also be concerned with proper disinfection of research laboratories when working with mycobacterial pathogens. Mycobacteria are difficult to kill and effective disinfectants tend to be very harsh and may be toxic as well. In the present study, we compared the use of 2 traditional disinfectants with a plant oil-based disinfectant. We found that the plant-based disinfectant was very effective kill mycobacteria, was nontoxic and safe for the environment.
Technical Abstract: Mycobacteria are difficult to kill due to the complexity of their cell wall. Further, Mycobacterium avium subsp. paratuberculosis (MAP) has one of the more elaborate cell wall compositions of all the mycobacteria. As a working pathogen within a research laboratory setting or as an environmental contaminant shed in the manure from infected animals, MAP is highly resistant to typical disinfectants. In the past, the most successful disinfectants to kill mycobacteria were based upon phenolics, harsh compounds that can break down the lipids within the cell wall. New disinfectants have been developed that are less toxic to the environment, however, it is unknown how well they perform compared to more traditional disinfectants. In the present study, we present comparative data on the utility of a commercial eco-friendly disinfectant, Benefect', compared to Amphyl', a phenolic-based disinfectant, and Lysol, a quaternary ammonium-based disinfectant, to kill MAP in pure culture, tissues, and manure. Results demonstrated that Benefect was highly effective with up to 100% kill of MAP within 30 min in all experiments, paralleling results obtained with Amphyl. Lysol performed the most poorly, requiring longer contact times to kill MAP. These results suggest that natural, nontoxic ingredients can be used to disinfect even hearty pathogens such as MAP effectively, both within the laboratory and on-farm.