Infectious Megaenteron of Mice

A large number of coliform organisms of an unusual biotype was isolated frequently from the intestinal tract and sometimes from the liver and spleen of mice affected with megaenteron (Muto et al., 1969) . In contrast, only a few healthy mice harbored the organisms in their guts. When healthy mice were inoculated orally with the organisms, a fatal diarrheal disease, indistinguishable clinically and pathologically from the natural cases, developed consistently in 1-week-aged mice after an 8- to 10-day incubation period. Weanlings aged 4 weeks were also affected but not so severely as sucklings. Bacteria-free filtrate of the intestines of diseased mice failed to affect sucklings by oral administration. Thus, the organisms of the biotype were regarded as the causative agent of megaenteron of mice.