Thermal resistance of Clostridium difficile endospores in dairy compost upon exposure to wet and dry heat treatments

Aim Thermal resistance of Clostridium difficile endospores in finished dairy compost was compared at 55 and 65°C under wet and dry heat conditions. Methods and Results A three‐strain cocktail of C. difficile endospores was inoculated into dairy compost to a final concentration of c. 5·5 log CFU per gram and the moisture content (MC) of the compost was adjusted to be 20, 30 and 40%. For the dry heat treatment at 55 and 65°C, the compost samples were placed in an environmental chamber, whereas for the wet heat treatment, the inoculated compost samples were placed in a tray submerged in a water bath. The MCs of composts were maintained well throughout the wet heat treatment while the dry heat treatment reduced the MCs of composts to