Scientists Unlock Evolution of Cholera, Identify Strain Responsible for Early Pandemics that Killed Millions

Jonathan Liu
January 14th, 2014

Published: January 9th, 2014

URL: http://www.sciencedaily.com/releases/2014/01/140109003802.htm

Summary: Researchers at McMaster University and the University of Sydney discovered early strains of cholera in samples of preserved intestines that were in a medical-history museum. Cholera is a deadly water-borne pathogen that has caused the deaths of millions over the past couple hundred years. Researchers have now mapped the entire genome of the pathogen, hoping to be able to understand it more now that they have the complete genome. They nicknamed the early strain as the "classical" version, which they think has caused 5 of the 7 major outbreaks in the 1800s, which most likely came from the Bay of Bengal. Researchers hadn't been able to sequence early versions cholera before because cholera thrives in the instestines, and so skeletal remains have no traces of the pathogen. Then they stumbled onto the medical-history museum, which had preserved instestines that had the early cholera. Researchers think that by analyzing the early version, we will be able to better understand the current strain, called El Tor, better. The El Tor strain seems to have completely replaced the classical strain since the 1960s for reasons not known and was the cause of the outbreak in Haiti after the earthquake.

Relevance: One of the topics we studied this term was evolution. This article directly relates to evolution, as it discusses the evolution of the dangerous pathogen cholera. The classical strain and the El Tor strain are both strains of cholera, however they are different species, but they have the same ancestor. This also relates to our evolution topic as it talks about two different strains that have the same ancestor. Lastly, the article also talks about DNA and mapping the genome of the early strain, which relates to the earlier unit heredity and genetics that we did this term.