Kitasato Shibasaburō

Kitasato Shibasaburō was a pioneering Japanese physician and bacteriologist. A bacteriologist is a scientist who studies bacteria, the tiny organisms that can cause disease. Kitasato dedicated his life to understanding infectious diseases and improving public health. His work helped create new ways to treat sickness and prevent its spread. Because of his massive contributions to medicine, his portrait now appears on the Japanese 1,000 yen banknote.

One of Kitasato's most significant achievements was his work with serum therapy. In 1889, he became the first person to grow the tetanus bacillus in a pure culture. A pure culture is a laboratory method where only one specific type of germ is grown at a time. In 1890, he worked with scientist Emil von Behring in Berlin to develop a serum therapy for tetanus. They demonstrated how this worked by giving graded injections of blood serum from an infected animal to a healthy animal. This process created passive immunity, which helps a body defend itself against a disease. This discovery helped launch the field of serotherapy, which has benefited people worldwide.

Kitasato's research extended to several different types of harmful bacteria. Along with his work on tetanus, he developed antitoxins for diphtheria and anthrax. An antitoxin is a substance that works against a specific toxin produced by a germ. His work on diphtheria, alongside von Behring, was so important that von Behring received a Nobel Prize in 1901. While Kitasato was also nominated for the first annual Nobel Prize in Physiology or Medicine that year, he did not receive it. Kitasato also showed that dead cultures could be used effectively in vaccination. Later, in 1898, he and his student Shiga Kiyoshi isolated the organism that causes dysentery.

Kitasato's scientific journey took him from Japan to the famous laboratories of Europe. He was born in Okuni village in Higo Province. He studied at Kumamoto Medical School before traveling to Germany. From 1885 to 1891, he studied at the University of Berlin under the famous scientist Robert Koch. After his time in Germany, he returned to Japan in 1891. With the help of Fukuzawa Yukichi, he founded the Institute for Study of Infectious Diseases.

During times of crisis, Kitasato was often called upon to help manage disease outbreaks. In 1894, the Japanese government requested his help in Hong Kong during a bubonic plague outbreak. Kitasato identified the bacterium responsible for the plague. A scientist named Alexandre Yersin discovered the same organism just a few days later. Some historians give Yersin sole credit because Kitasato's early reports were sometimes vague or inaccurate. However, modern microbiologists believe Kitasato likely faced contamination from pneumococci in his samples. They argue there is little doubt he successfully isolated and characterized the plague bacillus.

Kitasato remained committed to public health throughout his entire career. In 1911, he traveled to Manchuria to study the prevention of a severe pneumonic plague. He spent much of his later life researching tuberculosis, a serious lung disease. When the Institute for Infectious Diseases was incorporated into Tokyo Imperial University in 1914, Kitasato resigned in protest. Instead, he founded the Kitasato Institute, which eventually became Kitasato University. He also helped start a company in 1921 to manufacture reliable clinical thermometers. This company was later renamed the Terumo Corporation.

Beyond the laboratory, Kitasato held many important leadership roles in society. He served as the first dean of medicine at Keio University and the first president of the Japan Medical Association. He was also a member of the House of Peers and was ennobled as a baron in 1924. His influence reached far beyond Japan, as he was elected an International Member of the American Philosophical Society in 1914. Kitasato died in Tokyo on June 13, 1931, following an intracranial hemorrhage. His legacy lives on through the many medical institutions and scientific advancements that bear his name.