The vast majority of chronic bacterial infections involve
the formation of biofilms. On their own, individual bacteria tend not to
represent much of a threat when met with the average human’s immune arsenal.
However, some types of bacteria have developed a particularly effective
defensive strategy. By grouping together
into slimy aggregate colonies, otherwise known as biofilms, bacteria can make
themselves virtually impervious to destruction through conventional means. Once a biofilm forms, an infection may become chronic, or even fatal.
Luckily for us, researchers at the University of Washington,
Seattle have developed a new method to turn bacteria’s best defensive strategy
against them.
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| Credit: ACS Sustainable Chem. Eng. |
In order to form a biofilm, bacteria secrete polysaccerides
and proteins which in turn form an extracellular matrix. As a consequence,
their external environment becomes unusually saturated with dissolved salts and
sugar, resulting in increased osmotic pressure on the cells. In order to
compensate, bacteria fill their internal cytoplasm with small molecules called,
unsurprisingly, osmoprotectants.
Researchers have focused their attention on these
osmoprotectants. By synthesizing artificial analogs in the lab, they have been
able to investigate various compounds that might interfere with their
effectiveness. Ethylcoline appeared to be the most promising. It reduced
biomass by 70%, and was the only compound tested that produced substantial
effects without inhibiting bacterial growth.
Strange as it may seem, the fact that this approach doesn’t
directly kill the bacteria is actually what makes it so appealing. By leaving the
cells alive, selective pressure is minimized, making it incredibly difficult
for the bacteria to adapt.
Source
Madhusoodanan, J. (2014). Simple Molecules Block Bacterial Biofilms | Chemical & Engineering News. [online] Cen.acs.org. Available at: http://cen.acs.org/articles/92/web/2014/10/Simple-Molecules-Block-Bacterial-Biofilms.html [Accessed 15 Oct. 2014].
