Survival of Mycobacterium paratuberculosis in the environment.

Abstract

Reducing the survival of Mycobacterium paratuberculosis (Mptb)outside the host animal has long been attributed to environmental factors such as elevated temperature, pH, ultraviolet light and dryness although without direct scientific evidence of the contribution of these factors. The experiment reported here evauluates these four factors - ultraviolet radiation, soil tepmperature, pH, moisture plus organic matter - for their effect on the survival of Mptb from soil as measured by proportional recovery using the Whitlock double incubation and BACTEC culture method. In this study, soil moisture and soil temperature were the most significant environmental factors affecting the survival or death of Mptb. Ultraviolet radiation appeared to have no effect and different soil types and variable sensitivity of culture obscured the effect of pH.