Genetic difference in susceptibility and fatality of three strains of miceexperimentally infected with Neodiplostomum seoulense

The genetic influence on host susceptibility to Neodiplostomum seoulense in fection and fatality of the host was studied in 3 inbred strains of mice (B ALB/c [H-2d], C3H/He [H-2k], and C57BL/6 [H-2b]). The survival of the mice, worm expulsion kinetics, worm size, number of eggs produced per day (EPD), and number of uterine eggs were observed from day 1 to day 40 postinfectio n (PI) with 100 or 200 metacercariae per mouse. Infection with N. seoulense was highly lethal to all 3 strains of mice, but the lethality was dose-dep endent and varied according-to the genetic backgrounds of the mice. The C3H /He mice exhibited the highest mortality, the lowest worm burdens and EPD, and the quickest expulsion of worms. It is suggested that different genetic backgrounds of mice appear to affect the host's capacity to expel N. seoul ense and the fatality of the hosts themselves.