Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Swimming 'to the left' gets bacteria upstream, and may promote infection

28.02.2007
Yale engineers who study both flow hydrodynamics and how bacteria propel themselves report that one reason for the high incidence of infections associated with catheters in hospital patients may be that some pathogenic bacteria swim "to the left," in a study published in Physical Review Letters.

"Escherichia coli (E. coli) and some other pathogenic bacteria with flagella interact with the flow of liquid when they are near a surface," said Hür Köser, assistant professor of electrical engineering at Yale and the study's senior author, who has collaborated with a diverse team of scientists for this study.

"Each cell normally has two to six flagella that can rotate together as a bundle and act as a propeller to drive the cell forward. Away from any boundaries, the cells swim in a straight line, but near a surface, opposing forces of flow and bacterial forward motion cause the bacteria to continuously swim to one side — to the left." The study determined that swimming "to the left" is a hydrodynamic process that is fundamentally related to the way the cells propel themselves in this manner.

Köser and his colleagues show that this phenomenon allows flagellated bacteria, such as E. coli, to find crevices or imperfections on the surface, get trapped, and swim upstream. This allows the bacteria to eventually locate large reservoirs with richer sources of food and better conditions for multiplying.

"We think that upstream swimming of bacteria may be relevant to the transport of E. coli in the urinary tract," said Köser. "It might also explain the high rates of infection in catheterized patients and the incidence of microbial contamination at protected wellheads. To our knowledge, this is the first time that a natural propensity to swim upstream has been discovered and described in bacteria."

To study the hydrodynamics of these bacteria in a flow environment, Köser's team constructed microfluidic devices using soft lithography. Inside the devices they set up various flow patterns to observe the bacteria in channels that were only 150 or 300 microns wide and between 50 and 450 microns deep. They were able to observe how the bacteria moved at a wide range of flow rates — between 0.05 and 20 microliters per minute.

Janet Rettig Emanuel | EurekAlert!
Further information:
http://www.yale.edu

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>