Survival of Corynebacterium pseudotuberculosis in axenic purulent exudate on common barnyard fomites.

Several inanimate surfaces (eg, plastic, wood, and steel) and particulate fomites (eg, wood shavings, hay, straw, and feces), common to the environment of confined small ruminants, were inoculated with Corynebacterium pseudotuberculosis in axenic purulent exudate that had been surgically removed from a naturally occurring case of caprine caseous lymphadenitis. Each inoculated fomite was incubated at 37, 22, and 4 C, and the length of time that C pseudotuberculosis survived was determined by isolation of bacteria from the fomite. The organism remained viable longer when caseous lymphadenitis abscess contents were mixed with particulate fomites than when spread on surfaces. Incubation at lower temperatures generally extended the survival potential of C pseudotuberculosis. Depending on the particulate fomite and the incubation temperature, viable C pseudotuberculosis organisms were isolated for mean periods ranging from 7 to 55 days, whereas recovery of bacteria from surfaces varied from 1 to 8 days.