DNA predatory device in the cholera bacterium

Scientists have studied more into the mechanism of how the cholera bacterium stabs and kills other bacteria in order to obtain their genetic material and possibly increase its antibacterial resistance in the process.

When this bacterium invades the small intestine it causes cholera, a disease with symptoms of acute watery diarrhea which eventually leads to dehydration.

This bacterium is naturally found in the sea attached to small planktonic crustaceans. It feeds on the chitin of their shells. When chitin is available, the cholera bacterium enters a phase known as “natural competence” in which it attacks surrounding bacteria regardless of species using a small spear like weapon called “type VI secretion system” in order to destroy them and obtain their genetic material afterwards.

Researchers conducted tests using this bacterium. They grew them on chitin surfaces to simulate natural environment. They observed that their “type VI secretion system” is also used in the transfer of genes. They used genetic and bio imaging techniques in order to identify which mechanisms are involved in this type of gene transfer as it happens in real time and observed that a cholera bacterium can obtain at least 40 genes from another bacterium.

This is important research because most bacteria use horizontal gene transfer which leads to an increase in antibacterial resistance and dispersal of virulence factors. If we can better understand the mechanisms that bacteria use in order to obtain genes for antibacterial resistance and virulence factors, we may be able to develop better ways to combat these disease causing bacteria.

http://www.sciencedaily.com/releases/2015/01/150101163629.htm Main article

http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1002778