Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

And So They Beat on, Flagella Against the Cantilever

17.09.2014

Monitoring the isolated vibrations of E. coli on a cantilever allows scientists to assess colony health in real time – a potential new screen for antibiotics and cancer drugs

A team of researchers at Boston University and Stanford University School of Medicine has developed a new model to study the motion patterns of bacteria in real time and to determine how these motions relate to communication within a bacterial colony.


L. Li and C. Lissandrello / Boston University

Illustration of a microcantilever sensor with E. coli bacteria attached and a close-up illustration of a single bacterium (inset). The motion of the bacteria couple to the cantilever and the cantilever motion is detected using the optical beam deflection technique.

The researchers chemically attached colonies of Escherichia coli bacteria to a microcantilever – a microscopic beam anchored at one end, similar to a diving board – thus coupling its motion to that of the bacteria. As the cantilever itself isn’t doesn’t generate any vibrations, or ‘noise,’ this allowed the researchers to monitor the colony’s reactions to various stimuli in real time.

“When they die, they stop moving, so it’s a good way to measure the effectiveness of an antibiotic,” said Kamil Ekinci, an associate professor at Boston University. He and fellow researchers describe their work in the journal Applied Physics Letters, which is produced by AIP Publishing. “You know more or less immediately that they’re dead.”

The traditional method of assessing a bacteria’s antibiotic susceptibility– culturing bacteria on agar plates infused with antibiotics – is quite time-consuming in comparison, and can take up to a day to produce results.

“Here in this system – down to a couple hundred of bacteria – we’re able to see their responses to external stimuli such as drugs,” said Utkan Demirci, an associate professor at Stanford University School of Medicine. “This also potentially applies to other types of cells, such as drug resistance in cancer.”

While cantilevers have been used before to characterize cellular mechanics, Ekinci and Demirci bring a new approach to look at cellular movement and noise in natural systems, hoping to eventually develop a disposable microfluidic chip.

“It’s a new direction for tool development,” Demirci said. “It could allow us to address some interesting biological questions in the antibiotic resistance and evolution space.”

Ekinci also found that when the amplitude of the bacteria’s random movements was plotted against their frequency, a distinct, familiar pattern began to emerge.

“We saw that the fluctuations were focused at certain frequencies – they weren’t like white noise,” Ekinci said. Not quite white, but rather, something closer to pink.

1/f-type noise, also known as pink-like noise, is a recurring pattern in which the power spectral density of a signal is inversely proportional to its frequency. This occurs within a wide variety of systems, including biological processes such as the random firing of neuron channels and the electrocardiogram of a heart’s rhythms, as well as in mechanical processes such as background noise in electronic devices and pitch progression in classical music.

“We think that there are several different time scales in the motion of these bacteria, and when you look at them collectively, you see 1/f-type behavior,” Ekinci said.

In addition to the long-term goal of creating smaller, portable sensors, future work includes identifying the precise structural sources of vibrations, in order to develop a quantitative physical model of the noise and better understand the bacterial communication pathways.

“I want to make this more quantitative and determine the sources of these noises,” Ekinci said. “I think this could be a useful tool for doing some fundamental studies.”

The article, "Nanomechanical motion of Escherichia coli adhered to a surface," is authored by C. Lissandrello, F. Inci, Utkan Demirci and Kamil L. Ekinci. It will appear in the journal Applied Physics Letters on September 16, 2014. After that date, it can be accessed at:
http://scitation.aip.org/content/aip/journal/apl/105/11/10.1063/1.4895132

ABOUT THE JOURNAL

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See: http://apl.aip.org

Contact Information

Jason Socrates Bardi
+1 240-535-4954
jbardi@aip.org
@jasonbardi

Jason Socrates Bardi | newswise

Further reports about: AIP Applied Physics Letters Escherichia coli bacteria bacterial physics stimuli vibrations

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Big data approach to predict protein structure

27.03.2017 | Life Sciences

Parallel computation provides deeper insight into brain function

27.03.2017 | Life Sciences

Weather extremes: Humans likely influence giant airstreams

27.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>