Foodborne Sporothrix schenckii: Infectivity for mice by intraperitoneal and intragastric inoculation with conidia

Experimental infections with a foodborne isolate of the fungus Sporothrix schenckii were administered to mice by intraperitoneal or intragastric injection and gavage. All injected mice showed evidence of systemic sporotrichosis. Granulomas were observed from day 3 to day 12 in the organs of neonates inoculated by injection; in mice infected by gavage, granulomas were observed only in those inoculated with 10⁷ conidia. Susceptibility (based on cultural recovery) of the neonates to infections with 6×10⁶ conidia of the fungus was 100% with intragastric injection, 91% with intraperitoneal injection, and 21 and 24% (2×10⁷ conidia) with oral intubation. With both intragastric (59%) and intraperitoneal (25%) injections, more neonates died or were cannibalized by the mother than with intubation (14.5%). S. schenckii infected neonatal mice and caused illness by the oral route as well as by injection into the tissues or stomach. Adult mice, however, were susceptible to S. schenckii only by injection into the tissues, but not by gavage.