Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Together We Stand: Bacteria Organize to Survive Hostile Zones

19.11.2007
Microfluidic Device May Reveal Ways to Fight Antibiotic-Resistant Biofilms

Using an innovative device with microscopic chambers, researchers from four institutions, including Johns Hopkins, have gleaned important new information about how bacteria survive in hostile environments by forming antibiotic- resistant communities called biofilms. These biofilms play key roles in cystic fibrosis, urinary tract infections and other illnesses, and the researchers say their findings could help in the development of new treatments and preventive measures.

"There is a perception that single-celled organisms are asocial, but that is misguided," said Andre Levchenko, assistant professor of biomedical engineering in The Johns Hopkins University's Whiting School of Engineering and an affiliate of the university's Institute for NanoBioTechnology. "When bacteria are under stress which is the story of their lives they team up and form this collective called a biofilm. If you look at naturally occurring biofilms, they have very complicated architecture. They are like cities with channels for nutrients to go in and waste to go out."

With a better understanding of how and why bacteria form biofilms, researchers may be able to disrupt activity in the bacterial communities and block harmful effects on their human hosts. The team's findings were detailed in an article published in the November 2007 issue of the journal Public Library of Science Biology.

... more about:
»bacteria »resistance

In the article, the researchers from Johns Hopkins; Virginia Tech; the University of California, San Diego; and Lund University in Sweden reported on the observation of the bacteria E. coli growing in the cramped conditions of a new microfluidic device. The device, which allows scientists to use nanoscale volumes of cells in solution, contains a series of tiny chambers of various shapes and sizes that keep the bacteria uniformly suspended in a culture medium.

Levchenko and his colleagues recorded the behavior of single layers of cells using real-time microscopy. Computational models validated their experimental results and could predict the behavior of other bacterial species under similar pressures. "We were surprised to find that cells growing in chambers of all sorts of shapes gradually organized themselves into highly regular structures," Levchenko said. "The computational model helped explain why this was happening and how it might be used by the cells to increase chances of survival."

The microfluidic device, which was designed and fabricated in collaboration with Alex Groisman's laboratory at UCSD, allows the cells to flow freely into and out of the chambers. Test volumes in the chambers were in the nano- liter range, allowing visualization of single E. coli cells. Ann Stevens' laboratory at Virginia Tech helped to generate new strains of bacteria that permitted visualization of individual cells grown in a single layer.

Hojung Cho, a Johns Hopkins biomedical engineering doctoral student from Levchenko's lab and lead author of the journal article, captured on video the gradual self- organization and eventual construction of bacterial biofilms over a 24-hour period, using real-time microscopy techniques. The experiments were matched to modeling analysis developed in collaboration with Cho's colleagues at Lund. Images were analyzed using tools developed with the participation of Bruno Jedynak of the Johns Hopkins Center for Imaging Science.

Observation using microscopy revealed that the longer the packed cell population resided in the chambers, the more ordered the biofilm structure became, Levchenko said. Being highly packed in a tiny space can be very challenging for cells, so that any type of a strategy to help colony survival can be very important, he adds.

Levchenko also noted that rod-shaped E. coli that were too short or too long typically either did not organize well or did not avoid "stampede-like" blockages toward the exits. The shape of the confining space also strongly affected the cell organization in a colony, with highly disordered groups of cells found at sharp corners but not in the circular shaped microchambers.

Understanding how bacteria produce biofilms is important to researchers developing better ways to combat the diseases associated with them, Levchenko pointed out. For example, people who suffer from cystic fibrosis a genetic disorder that affects the mucus lining of the lungs are susceptible to a species of bacteria that colonizes the lungs. Patients choke on the colony's byproducts. Chronic urinary tract infections result from bacterial communities that develop inside human cells. And biofilms cause problems in tissues where catheters have been inserted or where sutures have been used.

"You can put a patient on antibiotics, and it may seem that the infection has disappeared. But in a few months, it reappears, and it is usually in an antibiotic-resistant form," Levchenko says. To explore possible treatments, Levchenko said, the microfluidic device could be used as a tool to rapidly and simultaneously screen different types of drugs for their ability to prevent biofilms.

This research was supported by funding from the National Science Foundation, the National Institutes of Health and the Swedish Research Council.

Mary Spiro | EurekAlert!
Further information:
http://www.jhu.edu

Further reports about: bacteria resistance

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

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

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>