Alexandre Émile John Yersin (22 September 1863 – 1 March 1943) was a Swiss people-French people physician and bacteriologist. He is remembered for his work as a pioneer in microbiology and immunology. Yersin is the co-discoverer of both the Diphtheria and Tetanus toxins (1890 with Émile Roux) and of the Bacilli responsible for the bubonic plague (1894, with Kitasato Shibasaburō). The bacteria was later named in his honour: Yersinia pestis. Yersin also demonstrated for the first time that the same bacillus was present in the rodent as well as in the human disease, thus underlining the possible means of transmission.
In order to practice medicine in France, Yersin applied for and obtained French nationality in 1888. He then joined the recently created Pasteur Institute in 1889 as Roux's collaborator and together they discovered that Corynebacterium diphtheriae secreted a soluble toxin that was responsible for the effects of diphtheria.
From 1890 to 1894, Yersin became a ship's doctor for the Messageries Maritimes shipping company on the Saigon-Manila line and then on the Saigon-Haiphong line. He participated in one of the Auguste Pavie missions. He led three expeditions across the French Indochina (current Vietnam, Laos and Cambodia) in Southeast Asia. He never returned to Europe.
On 5 June 1894, he was sent, by request of the French government, on a mission to Hong Kong where an outbreak of plague had already caused 100,000 deaths from the plague. Just 15 days later, he isolated the plague bacillus, Yersinia pestis.
In 1895 he returned to the Institute Pasteur in Paris and with Émile Roux, Albert Calmette and Amédée Borrel, prepared the first anti-plague Antiserum. In the same year, he returned to Indochina, where he installed a small laboratory at Nha Trang to manufacture the serum (in 1905 this laboratory became a branch of the Pasteur Institute).
Yersin tried the serum received from Paris in Guangzhou and Amoy, in 1896, and in Bombay, India, in 1897, with disappointing results.
Having decided to stay in French Indochina, Yersin founded the Institut Pasteur in Nha Trang in 1895. While there he studied cattle breeding (to produce anti-plague serum).
Yersin tried his hand at agriculture and was a pioneer in the cultivation of ( Hevea brasiliensis) For this purpose, he obtained in 1897 a concession from the government to establish an agricultural station at Suoi Dau. He opened a new station at Hon Ba in 1915, where he acclimatized the quinine tree ( Cinchona ledgeriana), which was imported from the Andes in South America, and which produced the first known effective remedy for preventing and treating malaria. Yersin's trees enabled Indochina to meet its quinine needs during the Second World War. He also successfully introduced cacao and coffee to Indochina. He participated actively in the creation of the Medical School of Hanoi On 8 January 1902, Yersin was accredited to be the first Headmaster of Hanoi Medical University by the Governor-General of French Indochina, future president of France Paul Doumer.
In 1934 he was nominated honorary director of Pasteur Institute and a member of its Board of Administration.
Alexandre Yersin is well remembered in Vietnam, where he was affectionately called Ông Năm (Mr Nam/Five). This nickname due to his rank as a Colonel in the French army, with five horizontal lines in his army insignia.
The diphtheria toxin was the first bacterial toxin discovered. During their experiments, Emile Roux and his associates observed that this substance could be produced in horses and then extracted in large quantities without causing trauma. They decided to inoculate dozens of children at risk of diphtheria with the serum. Twice as many of the inoculated children survived as had been expected.
Antisera would be made from the diphtheria toxin by Emil von Behring (1854–1917) and Shibasaburo Kitasato (1853–1931), creating the first effective treatment for the disease.
The Japanese government sent Kitasato Shibasaburō, a bacteriologist, to investigate the plague. On 5 June, Kitasato departed Yokohama on SS City of Rio de Janeiro with a team of 5, arriving in Hong Kong on 12 June. On 14 June, Kitasato discovered that the bacillus, now known as Yersinia pestis, was the direct cause of the plague. However, he was doubtful of its significance as the autopsy was done 11 hours after death. His finding was reported by Lowson, who had supported Kitasato's work, to The Lancet. His report was published a week later, on 25 August.
Just three days after Kitasato's arrival, Yersin arrived alone in Hong Kong on 15 June. Yersin had travelled alone from French Indochina, carrying in his baggage a microscope, sterilizer, and culture supplies. He was sent there to investigate the outbreak by the government of France. Unlike Kitasato, Lowson did not offer Yersin support, as Lowson considered France to be a colonial competitor to Great Britain in East Asia. At the hospital, Yersin would find all the cadavers reserved for Kitasato.
Yersin was able to obtain specimens after bribing English sailors responsible for disposing of the bodies of plague victims. Yersin discovered the bacillus on 23 June. Even though Kitasato made the earlier discovery, Kitasato's description lacked precision, and the report was riddled with doubts and confusion.
The two rivals were introduced, but they exchanged little information in their common language of German. The story was related that, at a meeting of the two during an autopsy that Kitasato was conducting, Yersin was surprised to observe that Kitasato was examining blood rather than buboes. Yersin relayed the suggestion via an intermediary that buboes should be examined too, with the result that Kitasato subsequently examined buboes. Both men found bacteria that they designated as the cause of the disease.
Yersin correctly described his as Gram-negative, whereas Kitasato insisted that his organism was Gram-positive. Kitasato described his blood organism as diplococcal and his bubo organism as bacillary, causing confusion and suggesting to some that his cultures were contaminated by the pneumococcus. In the ensuing months and years, Kitasato asserted that his bacillus was different from that of Yersin.
During his first autopsy in Hong Kong, he related his method of obtaining fluid from the bubo, seeing Gram-negative bacilli, injecting animals that he observed to die with bacteria in their tissues, and sealing a bubo specimen in a glass tube that was immediately mailed to Paris. These specimens were received by Albert Calmette and Amedee Borrel who confirmed Yersin’s findings and carried out research with the bacteria to produce a therapeutic antiserum. Yersin was also able to demonstrate for the first time that the same bacillus was present in the rodent as well as in the human disease, thus underlining the possible means of transmission. This important discovery was communicated to the French Academy of Sciences in the same year, by his colleague Emile Duclaux, in a classic paper titled "La peste bubonique à Hong-Kong".
In 1895, Yersin returned to Paris to collaborate with his associates in Pasteur’s laboratories. Before the end of that year, he was back in Indochina, and in 1896 he went to Hong Kong again to treat plague victims with his new antiserum.
The name of the organism underwent several changes. It was Bacterium pestis until 1900, when it changed to Bacillus pestis. In 1923, it acquired a new designation as Pasteurella pestis, which it kept up to about 1970, when Yersin obtained posthumous honour through its final name, Yersinia pestis.
A 1976 thorough analysis of the morphology of the organism discovered by Kitasato determined that "we are confident that Kitasato had examined the plague bacillus in Hong Kong in late June and early July 1894", only days after Yersin announced his own discovery on 20 June, and that Kitasato "should not be denied this credit".
Following the country's independence, streets named in his honor kept their designation and his tomb in Suối Dầu was graced by a pagoda where rites are performed in his worship. Yersin Market in Ho Chi Minh City was named after him. His house in Nha Trang is now the Yersin Museum, and the epitaph on his tombstone describes him as a "Benefactor and humanist, venerated by the Vietnamese people".
In Hanoi, the Lycée français Alexandre Yersin, a French international school was named after him.
A private university founded in 2004 in Da Lat was named "Yersin University" in his honour Trường.
While in Hong Kong, Yersin was helped in his research by an Italian priest of the PIME order named Bernardo Vigano. He provided cadavers and assisted with his quest to find a remedy for the plague.
Discovery of exotoxins
Discovery of the plague bacterium
Death and legacy in Vietnam
Miscellaneous
Bibliography
English
French
Other languages
External links
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