Study of 1849 cholera victim's guts may help stop future outbreaks

The intestine of a US cholera victim from the mid-1800s has yielded new clues to the evolution of the deadly bacterium and may help prevent future outbreaks, researchers say.

Using the sample of an intestine, preserved in a jar at a Philadelphia medical museum, scientists reconstructed for the first time the genome of classical cholera, the predecessor of the modern strain.

Results published in suggest this strain, which led to five of seven deadly outbreaks in the 1800s, may be more virulent than latter-day counterparts.

Researchers hope their discovery could lead to a better understanding of today's strain of cholera, known as El Tor, which replaced the classical strain in the 1960s and is blamed for recent epidemics.

"Understanding the evolution of an infectious disease has tremendous potential for understanding its epidemiology, how it changes over time and what events play a role in its jump into humans," said evolutionary geneticist Hendrik Poinar, associate professor and director of the McMaster University ancient DNA centre.

The preserved organ was crucial to the effort, since DNA from cholera resides only in soft tissues and cannot be detected in bone.