Tag Archives: Yersinia pestis

“Modern Plague: Learning from the Past”

I have had a passing interest in the recent Plague outbreak in Madagascar. Living and working in provincial New Zealand, I don’t come across many cases of Plague. In fact I can safely say, I have never seen a case, and may well never do so. But as a microbiologist, I need to know something about the plague, just in case somebody asks…

The causative agent of Plague is Yersinia pestis. The other two main pathogenic bacteria in the Yersinia genus are Yersinia enterocolitica and Yersinia pseudotuberculosis

And I am bored to tears already… Rote learning is no way whatsoever to learn about bacteria, and especially ones like Y. pestis which most people will only encounter very rarely in real life.

When I think of plague, my mind turns to medieval London, Ring-a-ring-of-roses, Samuel Pepys, etc.

But most of all I think of the discoverer of the causative organism, Alexandre Yersin (picture above), a Swiss-French bacteriologist who has a fascinating life history. 

Born in Switzerland in 1863, he went to medical school in Lausanne, before ending up in Paris at Louis Pasteur’s research institute. There he was involved in the development of anti-rabies serum with Emile Roux. He joined the Pasteur Insitute in 1889 and again with Roux, discovered diptheria toxin.

He then worked as a doctor for a shipping company in South East Asia and it was during a secondment to Hong Kong in 1894 to investigate an outbreak of plague, that he discovered the pathogen responsible for causing plague. It was originally named Pasteurella pestis, but this has since been changed to Yersinia pestis in 1944.

As is often the case, there was a degree of controversy as to who was the first to make the discovery of Y. pestis. A fellow scientist, Kitasato Shibasaburo, made very similar findings to Yersin, but over the years, Yersin took most of the credit for the discovery due to the greater accuracy of his microbiological findings.

He then settled in and spent most of his life in Nha Trang, now in Vietnam.

He also directed a medical school in Hanoi, and was involved in establishing rubber trees and Cinchona trees (used for making quinine) in the region.

Alexandre Yersin died in Nha Trang in 1943, during World War II. A museum was set up in his former house and to this day, he is venerated by the Vietnamese people.

When you read about the history of a disease, it contextualises it, and thus the associated facts get remembered better.

So if you get asked to learn about Yersinia pestis, then go and read about Alexandre Yersin, go and read about The Great Plague of London, read about the living conditions, the rats, and the fleas… All you need to know about Yersinia pestis will be in such texts, and you will remember the stories.

And it is also far more interesting than reading a textbook

Michae