Bacteria use Batman-like grappling hooks to 'slingshot' on surfaces

Jul 18, 2011

Bacteria use various appendages to move across surfaces prior to forming multicellular bacterial biofilms. Some species display a particularly jerky form of movement known as "twitching" motility, which is made possible by hairlike structures on their surface called type IV pili, or TFP.

"TFP act like Batman's grappling hooks," said Gerard Wong, a professor of bioengineering and of chemistry and biochemistry at the UCLA Henry Samueli School of Engineering and Applied Science and the California Institute (CNSI) at UCLA. "These grappling hooks can extend and bind to a surface and retract and pull the cell along."

In a study to be published online this week in , Wong and his colleagues at UCLA Engineering identify the complex sequence of movements that make up this twitching motility in Pseudomonas aeruginosa, a biofilm-forming pathogen partly responsible for the seen in .

During their observations, Wong and his team made a surprising discovery. Using a high-speed camera and a novel two-point tracking algorithm, they noticed that the bacteria had the unique ability to "slingshot" on surfaces.

The team found that linear translational pulls of constant velocity alternated with velocity spikes that were 20 times faster but lasted only milliseconds. This action would repeat over and over again.

"The constant velocity is due to the pulling by multiple TFP; the velocity spike is due to the release of a single TFP," Wong said. "The release action leads to a fast slingshot motion that actually turns the bacteria efficiently by allowing it to over-steer."

The ability to turn and change direction is essential for bacteria to adapt to continually changing surface conditions as they form biofilms. The researchers found that the slingshot motion helped P. aeruginosa move much more efficiently through the polysaccharides they secrete on surfaces during formation, a phenomenon known as shear-thinning.

"If you look at the surfaces the bacteria have to move on, they are usually covered in goop. Bacterial cells secrete polysaccharides on surfaces, which are kind of like molasses," Wong said. "Because these are long polymer molecules that can get entangled, these are very viscous and can potentially impede movement. However, if you move very fast in these polymer fluids, the viscosity becomes much lower compared to when you're moving slowly. The fluid will then seem more like water than molasses. This kind of phenomenon is well known to chemical engineers and physicists."

Since the twitching motion of bacteria with TFP depends of the physical distributions of TFP on the surface of , Wong hopes that the analysis of motility patterns may in the future enable new methods for biometric "fingerprinting" of individual cells for single-cell diagnostics.

"It gives us the possibility of not just identifying species of but the possibility of also identifying individual cells. Perhaps in the future, we can look at a cell and try to find the same cell later on the basis of how it moves," he said.

Explore further: Top Japan lab dismisses ground-breaking stem cell study

Provided by University of California - Los Angeles

5 /5 (1 vote)

Related Stories

Researchers discover 'walking' properties of bacteria

Oct 08, 2010

(PhysOrg.com) -- Many drug-resistant infections are the result of bacterial biofilms, structured aggregates of bacteria that live on surfaces and that are extremely resistant to environmental stresses. These ...

Genes that make bacteria make up their minds

Mar 30, 2009

Bacteria are single cell organisms with no nervous system or brain. So how do individual bacterial cells living as part of a complex community called a biofilm "decide" between different physiological processes (such as movement ...

No hiding place for infecting bacteria

Mar 16, 2009

Scientists in Colorado have discovered a new approach to prevent bacterial infections from taking hold. Writing in the Journal of Medical Microbiology, Dr Quinn Parks and colleagues describe how they used enzymes against produc ...

Recommended for you

Top Japan lab dismisses ground-breaking stem cell study

Dec 26, 2014

Japan's top research institute on Friday hammered the final nail in the coffin of what was once billed as a ground-breaking stem cell study, dismissing it as flawed and saying the work could have been fabricated.

Research sheds light on what causes cells to divide

Dec 24, 2014

When a rapidly-growing cell divides into two smaller cells, what triggers the split? Is it the size the growing cell eventually reaches? Or is the real trigger the time period over which the cell keeps growing ...

Locking mechanism found for 'scissors' that cut DNA

Dec 24, 2014

Researchers at Johns Hopkins have discovered what keeps an enzyme from becoming overzealous in its clipping of DNA. Since controlled clipping is required for the production of specialized immune system proteins, ...

Scrapie could breach the species barrier

Dec 24, 2014

INRA scientists have shown for the first time that the pathogens responsible for scrapie in small ruminants (prions) have the potential to convert the human prion protein from a healthy state to a pathological ...

Extracting bioactive compounds from marine microalgae

Dec 24, 2014

Microalgae can produce high value health compounds like omega-3s , traditionally sourced from fish. With declining fish stocks, an alternative source is imperative. Published in the Pertanika Journal of Tr ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
not rated yet Jul 18, 2011
I'm sick of looking at this Dr. Life in the ad above, with his disproportionately small arms. It's freakish. He should be covered in this biofilm and be slingshot elsewhere.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.