Kitasato Shibasaburo (1852-1931), Japanese bacteriologist. Kitasato worked under Koch before founding a bacteriology institute in Japan. In 1889 he prepared the first pure culture of the tetanus bacillus, five years after the microbe's discovery. With Behring he discovered antitoxin immunity. By receiving an injection of a small amount of bacterial toxin, a patient gained a resistance to disease. Antitoxin immunity was used to combat tetanus and diphtheria. He discovered the plague bacillus, Yersinia pestis, independently of Yersin in 1894. Kitasabo also isolated the bacilli of symptomatic anthrax (1889) and dysentery (1898).