Abstract
The predominant subgroup of Shigella organisms in Japan was Shigella Flexneri, except a period just after the world war II. The pattern of isolated Shigella organisms, however, began to change in 1962 to 1963, and the rate of the number of Sh. Sonnei increased recently, thus the most of the organisms isolated in Japan are occupied by Sh. Sonnei now.
In April 1967 the endemic prevalence due to bacillary dysentery occured in a some primary school of Ichikawa City and 53 patients were admitted in Konodai Hospital. In this paper, the results of the bacteriological investigation on the serological identification of the isolated organisms and the drug susceptibility against them were reported, and they were compared with the data of another 25 cases by Sh. Sonnei which were isolated from the patients occured sporadically in the area of Ichikawa City and its neighborhood in 1967
