Kiyoshi Shiga. Portrait of Kiyoshi Shiga (1870- 1957), Japanese bacteriologist. In 1898 he dis- covered the Shigella dysenteriae bacillus, the cause of Shigellosis or bacillary dysentery. Shiga also discovered a vaccine to combat S. dysenteriae (formerly known as Bacillus dysenteriae). He had graduated from Tokyo University and was an assist- ant of Kitasato. He was an assistant to the German scientist Ehrlich during 1901-03 but returned to Japan to head the Kitasato Institute and in 1919 became professor at Keijo University. Shigellosis is an infection of the intestine caused by contact with contaminated human faeces; it causes frequent passing of stools mixed with blood, pus and mucus.