Bacteria can kill and steal genes from others

A Swiss research team is warning that harmful bacteria, such as cholera, can kill neighbouring bacteria, then steal up to 40 of the genes to ramp up their killing power.

It enables the cholera bacteria to develop into a far more dangerous strain, says Melanie Blokesch from the Swiss Federal Institutes of Technology.

The bacteria use a tiny spear to kill their neighbours, she explains, even cousins of the same type of bacteria.

This is called “horizontal gene transfer” which enables a single cholera bacterium to become more virulent by absorbing the traits of its prey, the researchers said.

Cholera is caused when the bacterium Vibrio cholerae infects the small intestine. The disease is characterised by acute watery diarrhoea resulting in severe dehydration.

“Using this mode of DNA acquisition, a single V. cholerae cell can absorb fragments containing more than 40 genes from another bacterium,” said Blokesch.

The tiny killing device that the bacterium uses is called the “type VI secretion system” and is known to exist in many types of bacteria.

There's another issue I remember from the Swan Committee Report in England in the late 1960s. Transpons are able to ferry genes among bacteria. 

It's why antibiotic resistance can transfer, even when the antibiotics are no longer being used.