Studies on the Experimental Shigella infection in Mice with Particular Consideration on Some Pretreatments Affecting the Persistence of Shigella in Intestine

Abstract

Experimental Shigella infection has already been investigated with a variety of experimental animals, with the resulting fact that it is quite difficult to infect normal animals by peroral administration of Shigella.
Experimental dysentery was induced to mice by peroral administration of Sh. flex. 2b for the purpose of therapeutic studies as well as of clarifying biological meanings of the intestinal flora.
The results were as follows:
1) In the non-pretreated group given Shigella orally, positive culture was observed only for two or three days without any symptom such as diarrhea.
2) Pretreatment by streptomycin prolonged the persistency of Shigella in intestine, the longest being for 114 days.
3) Cortison and X-ray irradiation were also effective for the prolongation of positive culture to a certain degree.
4) Pretreatment by sensitization with homo- and heterologous antigens was not effective in extending the period of positive culture.
5) Injecting of CCl₄ and yellow phosphorus prolonged the period of positive culture to a great extent.
6) Administration of opium tincture had also some effect on it.
7) Based on these results, the problem as for the persistence of dysentery bacilli in intestine was discussed.