Bacterial communication considered for medical applications

Aug 29, 2014 by Geoff Vivian
These she then inspected for bioluminescence, which is an indicator of quorum sensing. Credit: Kris Williams

A local microbiologist has been working on an alternative to antibiotics, which tend to encourage resistant bacterial strains to develop over time.

Rather than attempting to destroy , UWA expert Dr Jamie Lindthorne focussed her PhD study on a phenomenon known as quorum sensing inhibition.

"Quorum sensing is a communication process that bacteria use to talk to each other, to make sure that they time the production of specific compounds together," she says.

She gave the example of a single bacterium present inside a human body—it is unlikely to emit any harmful toxins unless it detects a chemical emitted by its fellow bacteria, called an "auto inducer".

"If it's on its own and starts producing a toxin then the body can now turn attack against it, so it gets overwhelmed rather quickly," she says.

"They wait until there's a lot of them together to actually make an effect."

Certain other organisms, such as those present in soil, have been found to emit chemicals of their own that inhibit quorum sensing—a phenomenon she calls quorum quenching.

"Quorum quenching is any method that inhibits quorum sensing," she says.

"Normally it's through degradation of the auto inducer, but it can be blocking receptors on the bacterial cell surface or anything like that."

Dr Lindthorne was interested in finding marine and river micro-organisms with quorum quenching capabilities.

She says bacteria producing quorum quenching compounds are usually identified after collecting bacterial samples, which they culture, before purifying and testing each isolate—but she wanted to find a quicker method.

Taking water samples from several locations in the Swan River and Cockburn Sound, she spread a diluted portion of each sample over agar plates which she cultured to produce mature .

Before attempting to identify any of these bacteria, she tested their quorum quenching properties on Vibrio harveyi, a bacterial strain first isolated from the surface of a sea mullet.

Dr Lindthorne then carefully spread distilled water, inoculated with V. harveyi, over the plates with a sterilised air brush.

These she then inspected for bioluminescence, which is an indicator of .

Several colonies showed a lack of bioluminescence, which she interpreted as a sign of their quorum quenching property.

She removed these colonies, re-cultured them, and ran genetic analyses to ascertain their genus.

While she is presently working in another area of microbiology, she says further research would have enormous potential for medical, agricultural and industrial applications.

Explore further: Inhibition of oral biofilm and cell-cell communication using natural-products derivatives

More information: "A Direct Pre-screen for Marine Bacteria Producing Compounds Inhibiting Quorum Sensing Reveals Diverse Planktonic Bacteria that are Bioactive." Linthorne JS, Chang BJ, Flematti GR, Ghisalberti EL, Sutton DC. Mar Biotechnol (NY). 2014 Aug 1. [Epub ahead of print]. www.ncbi.nlm.nih.gov/pubmed/25082352

add to favorites email to friend print save as pdf

Related Stories

Chemists find new compounds to curb staph infection

May 23, 2013

(Phys.org) —In an age when microbial pathogens are growing increasingly resistant to the conventional antibiotics used to tamp down infection, a team of Wisconsin scientists has synthesized a potent new ...

Fighting bacteria's strength in numbers

May 17, 2012

Scientists at The University of Nottingham have opened the way for more accurate research into new ways to fight dangerous bacterial infections by proving a long-held theory about how bacteria communicate ...

Recommended for you

Scientists see how plants optimize their repair

10 hours ago

Researchers led by a Washington State University biologist have found the optimal mechanism by which plants heal the botanical equivalent of a bad sunburn. Their work, published in the Proceedings of the Na ...

Structure of an iron-transport protein revealed

16 hours ago

For the first time, the three dimensional structure of the protein that is essential for iron import into cells, has been elucidated. Biochemists of the University of Zurich have paved the way towards a better ...

Over-organizing repair cells set the stage for fibrosis

17 hours ago

The excessive activity of repair cells in the early stages of tissue recovery sets the stage for fibrosis by priming the activation of an important growth factor, according to a study in The Journal of Ce ...

User comments : 0