Yersin Alexandre Émile John

Yer·sin

(yĕr-sä′), Alexandre Émile John 1863-1943.
French bacteriologist. With Émile Roux, he isolated the toxin that causes the symptoms of diphtheria. Yersin later discovered the bacillus that causes bubonic plague and developed a serum to protect against it.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.