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 Squeezing light at the nanoscale
18.06.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht The Fraunhofer IAF is a »Landmark in the Land of Ideas«
15.06.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

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: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>