Microbial Nanomotion Measured How Bacteria Stop Producing Sounds When Killed by Antibiotic

Imagine bacteria that produce sounds. By listening to these microbes, it is possible to determine if they are alive or not.

As specified in an AzoNano report, the bacteria would stop producing sounds if they were killed by an antibiotic unless they were resistant to the drug.

This is exactly what a group of TU Delft researchers led by Dr. Farbod Alijani has attained. The team specifically used graphene to capture low-level noise in a single bacterium.

At first, the Alijani-led team was interested in the fundamentals of graphene mechanics, although they became curious about what could occur if this extremely sensitive material came into contact with a single biological entity.

Flagella

In their research published in the Nature Nanotechnology journal, the study investigators started working with the nanobiology group of Cees Dekker and the nanomechanics group of Peter Steeneken.

The team carried out their first experiments with E. coli bacteria with the help of Irek Roslon, a Ph.D. student and postdoc, Dr. Aleksandre Japaridze.

Essentially, the tiny oscillations result from the biological processes of bacteria, with their flagella playing a vital and major role.

Vedantu.com described flagella as "microscopic hair-like structured organisms" that help in the cell's movement ad are mostly unicellular.

The same report said that flagella mean "whip" due to its whip-like appearance that helps propel a cell through fluids.

Flagellar Beats in Graphene

To understand how small the flagellar beats in graphene are, it is worthy to say that they are at least 10 billion times tinier compared to the punch of a boxer when reaching a punching bag.

Alijani commented, yet, such nanoscale beats can be converted to soundtracks and listened to, "and how cool is that?"

This research has far-reaching implications for the detection of antibiotic resistance. The results of the investigation were precise. If the microbes were resistant to the antibiotic, the oscillations continued at a similar level.

Vibrations decreased until one to two hours after the bacteria were sensitive to antibiotics, but they were gone.

Such a phenomenon can be detected with only a single cell because of the high sensitivity of graphene drums.

Graphene Drums

A related Physics Report said researchers have developed a suite of mechanisms to meet the challenge of noninvasively probing "cell biomechanics."

Like those employed in atomic force microscopy, cantilevers have become particularly famous for microbial cell populations.

Essentially, the cells are sticking to the probe and bending the cantilever with their motion. However, that approach needs hundreds or even thousands to produce enough vibrations to overpower environmental noise.

The study investigators found that graphene nanodrums could be used to track the time-dependent response of a cell to a stimulus or determine individual antibiotic-resistant bacteria in a population.

Lastly, the devices could potentially be incorporated into fast screening tests for the development of drugs or customized medical treatments.

Related information about bacterial growth is shown on MSU Extension Produce Safety's YouTube video below:

Check out more news and information on Graphene in Science Times.