MAY 11, 2020 8:13 AM PDT

Bacteria Can Tumble Their Way Out of Traps

WRITTEN BY: Carmen Leitch

We share the world with vast numbers of microbes, many of which are able to move around freely in the environment. Most, however, tend to stop moving and grow colonies and biofilms. Tumbling bacteria first have to slow their motion and orient themselves properly before they can settle into their ideal environment.

Whip-like flagellae sprout from E. coli's exterior, while numerous shorter fimbriae give the germ a furry look. / Credit: CDC/ Antibiotic Resistance Coordination and Strategy Unit / Alissa Eckert - Medical Illustrator

Researchers have investigated this process in Escherichia coli. They found that the bacteria run in circles when they're near a solid surface. The microbes can trace loop after loop like a microscopic figure skater. Scientists analyzed the motion of E. coli step by step and determined that they can tumble along a surface. The findings have been reported in the Biophysical Journal.

"Tumbles are very interesting. The bacteria itself does not know where the environment is preferential for them," said the first author of the study Laurence Lemelle, a biophysicist at École Normale Supérieure de Lyon (Normal School of Lyon). "It doesn't know where to go, how to feel things. But it knows if the past environment was better or worse than the present."

As bacteria learn more about their environment, they can stop their tumbling or slow it down. "This means you swim more towards a direction; at the end, the population statistically swims towards the preferential conditions," she added.

It has been predicted that bacteria don't tumble near a surface; they swim. But biophysics would predict that if bacteria only swam, they'd be trapped in infinite loops.

While it's challenging, these microbes can be tracked. E. coli propel themselves forward using appendages called flagella. They can swim twenty times their body length in a second, and tumble in only a tenth of a second. The tumble is so rapid, a high-magnification, high-speed camera with night vision had to be built to watch them.

As bacteria are swimming in water near the surface, their trajectory bends because of water friction on their cell. They have to tumble to keep from being trapped in circles on the surface, decelerating to do so. The flagellum can reorient the bacteria, kick off the surface, or accelerate the movement as well.

"We now know that bacteria can tumble on surfaces, and these tumbles are very specific," said Lemelle. "Elucidating the strategy of surface exploration that is underlined by these tumbles is an important future step."

Bacteria can explore a surface by moving and tumbling. They can also swim along the surface of a cell until they contact a surface receptor that gives them entry into the cell. They are able to find the best places to form biofilms - like crevices that are hard to clean. These growths are tough to remove and can become antibiotic-resistant.

"Before...the COVID pandemic, it was difficult to convince people that we need to anticipate and develop alternative approaches to reduce the surface biocontamination," said Lemelle. "People were like, 'We have plenty of antibiotics. There's resistance, but we have time.' From a medical standpoint, understanding the near-surface tumbling events of bacteria can help limit the biocontamination of surfaces and develop antibacterial methods."

Sources: AAAS/Eurekalert! via Cell Press, Biophysical Journal

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 18, 2020
Microbiology
The Science of Pesto
AUG 18, 2020
The Science of Pesto
  The word pesto comes from the Genovese word pestâ (pestare in Italian) which means “to pound” o ...
SEP 04, 2020
Microbiology
Researchers Discover a Way to Use Microbes to Help Make Plastic
SEP 04, 2020
Researchers Discover a Way to Use Microbes to Help Make Plastic
Researchers have discovered that some bacteria can make ethylene in a way we never knew about; microbes that metabolize ...
SEP 11, 2020
Chemistry & Physics
Indigenous fermentation processes require complex chemical reactions
SEP 11, 2020
Indigenous fermentation processes require complex chemical reactions
A study published in the Nature journal Scientific Reports uncovers the complex chemical processes behind aborigina ...
OCT 25, 2020
Microbiology
Over Time, Plague Infections Spread Faster
OCT 25, 2020
Over Time, Plague Infections Spread Faster
From the time of the Black Death, around 1348 and the Great Plague of 1665, epidemics of plague occurred in Europe. Rese ...
NOV 05, 2020
Clinical & Molecular DX
Digging DEEP into Metabolomic Space
NOV 05, 2020
Digging DEEP into Metabolomic Space
Metabolomics is an umbrella term encompassing lipidomics and the study of smaller polar metabolites.  As such, more ...
NOV 08, 2020
Genetics & Genomics
Drug-Resistant Microbes Persist in Hospitals After Deep Cleaning
NOV 08, 2020
Drug-Resistant Microbes Persist in Hospitals After Deep Cleaning
Researchers have found that drug-resistant bacteria can hang around even after deep cleaning. They used genome sequencin ...
Loading Comments...