Mycobacterium avium subsp. paratuberculosis excreted in cattle feces shows higher resistance to disinfectants than cultured cells

Abstract

As Johne's disease progresses, clumps of Mycobacterium avium subsp. paratuberculosis (MAP) are identified in the feces. MAP shows resistance to disinfectants, and effective disinfection methods for MAP cells excreted in feces have not been verified. Furthermore, given that biofilm-like vesicles and spore-like morphotypes were observed in feces from infected cattle, we aimed to compare reduction rates between cultured and naturally infected MAP cells after disinfectant treatment. Although the logarithmic reduction value for all cultured MAP cells was > 3.0, four of 10 infected MAP cells showed values < 2.0 after dichloroisocyanuric acid treatment. Our findings suggest that materials contaminated with infected cattle feces should be exposed to higher concentrations of disinfectants than those reported to be effective based on cultured cells.