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When did scientists identify Yersinia pestis as the cause of plague?

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Medieval illustration of Brotherhood of the Cross flagellants in robes and pointed hats walking in procession, some carrying a crucifix and banners, during the Black Death. — Black Death Flagellants in the Netherlands scourging themselves in atonement, believing that the Black Death is a punishment from God for their sins, 1349.

Scientists identified the bacterium Yersinia pestis as the cause of plague in 1894. During an outbreak in Hong Kong, the organism was isolated independently by two bacteriologists: the French scientist Alexandre Yersin and the Japanese physician Kitasato Shibasaburo.123

While the Black Death occurred in the 14th century, the medical understanding of infectious organisms did not exist at that time, and the disease was historically attributed to "poisonous miasma". Modern research and the use of DNA-based approaches have since confirmed that Y. pestis was the pathogen responsible for the Black Death by detecting its genetic material in archaeological remains.214