Protective Effect on Infections with Vibrio cholerae in Suckling Mice Caused by the Passive Immunization with Milk of Immune Mothers

The oral infection in suckling mice, strain ICR, with strains of Vibrio cholerae has been reported, in which the multiplication of vibrios, accumulation of fluid in the intestine, diarrhea, and death were observed [1]. In the study, it was observed that experimental cholera was produced only in sucklings younger than about 10 days of age. The infant rabbit [2, 3] and canine [4, 5] models of experimental cholera had already been studied and developed by several authors. Compared with these models, suckling mice offer the following advantages, (i) The experimental cholera is easily produced by oral infection with a small inoculum of vibrios without any particular treatment except starvation for 1 day. (2) Experiments with a large number of mice are easy in contrast to those with infant rabbits or dogs. The ICR strain in particular has beneficial characteristics for use in experimental cholera: mothers have more than 10 babies in each litter and do not refuse to raise sucklings born of other mothers.