Navigation Links
Lucky bacteria strike it rich during formation of treatment-resistant colonies

In biology, we often think of natural selection and survival of the fittest. What about survival of the luckiest?

Like pioneers in search of a better life, bacteria on a surface wander around and often organize into highly resilient communities, known as biofilms. It turns out that a lucky few bacteria become the elite cells that start the colonies, and they organize in a rich-get-richer pattern similar to the distribution of wealth in the U.S. economy, according to a new study by researchers at UCLA, Northwestern University and the University of Washington.

The study, to be published online May 8 in the journal Nature, is the first to identify the strategy by which bacteria form initial colonies in biofilms. The research may have significant implications for battling stubborn bacterial infections that do not respond to powerful drugs, as well as for other applications.

Biofilms are colonies of bacteria that form on surfaces, including human tissue. Bacteria in biofilms change their gene expression patterns and are far more resistant to antibiotics and the body's immune defenses than individual, free-swimming bacteria, because they mass together and surround themselves with a matrix of proteins, DNA and sugars. This makes seemingly routine infections potentially deadly.

Gerard Wong, a professor in the UCLA bioengineering and chemistry departments; Erik Luijten, an associate professor of applied mathematics and of materials science and engineering at Northwestern University; and Matthew R. Parsek, a professor of microbiology at the University of Washington, led a team of researchers who elucidated the early formation of biofilms by using algorithms to track the development of different strains of the bacterium Pseudomonas aeruginosa and by conducting computer simulations to map the movements. P. aeruginosa can cause lethal, difficult-to-treat infections. Examples include infections found in cystic fibrosis and AIDS patients.

Surprisingly, the researchers found that the individual bacteria that start the formation of micro-colonies have no special inherent qualities.

As bacteria move across a surface, they leave trails composed of a specific type of polysaccharide, or long sugar molecules.

"Some of the bacteria remained fixed in position," Parsek said, "but some moved around on the surface, apparently randomly but leaving a trail that influenced the surface behavior of other bacteria that encountered it."

Bacteria arriving later also lay trails, but tend to be guided by the trails from the pioneers. This network of trails creates a process of positive feedback and enables bacteria to organize into micro-colonies that mature into biofilms. By being at the right place at the right time, and by using communally produced polysaccharides, a small number of lucky cells -- often ones that come later -- become the first to form micro-colonies, which give cells many survival advantages over other bacteria.

Interestingly, these biofilms develop in accordance with Zipf's Law, which is one special form of the rich-get-richer phenomena. A well-known example of this is the distribution of wealth in the United States. Recent statistics indicate that the wealthiest 20 percent of the population have more than 80 percent of the total wealth. Most of the wealth in this elite group is in turn owned by a small elite fraction within the elite, and so on.

"It turns out bacteria do the same thing," Wong said. "By effectively taking a census of bacteria using our recently developed methods, we find that the way they organize into micro-colonies is not random, as was previously thought."

Extending the economic analogy, Wong said the research may provide insight into how to fight antibiotic-resistant bacteria. "Typically, when we want to get rid of bacteria, we just kill them with antibiotics," he said. "As a result, they develop defense mechanisms and grow stronger. Maybe that's not always the best way to treat biofilms. Perhaps we can regulate bacterial communities the way we regulate economies. Our work suggests that new treatment options may use incentives and communications as well as punishment to control bacterial communities."

"A truly beautiful aspect of this work is how it relies on a combination of experiments and computer simulations," Luijten said. "Only through combination of the totally different types of expertise of three different research groups has it been possible to disentangle what is going on, and how polysaccharides influence the organization of bacteria into micro-colonies."


Contact: Megan Fellman
Northwestern University

Related biology technology :

1. MU researchers identify key plant immune response in fight against bacteria
2. Sheffield scientists shine a light on the detection of bacterial infection
3. Bacterial protein mops up viruses found in contaminated water supplies
4. Decades-old conclusion about energy-making pathway of cyanobacteria is corrected
5. Manipulating way bacteria talk could have practical applications, Texas A&M profs say
6. Scientists Discover How a Bacterial Pathogen Breaks Down Barriers to Enter and Infect Cells
7. Targeted antibacterial agent rapidly created in response to serious food safety pathogen
8. Cepheid Receives Grant to Develop Sample Processing and Amplification Methods for Detection of Bloodstream Bacteria
9. U Alberta finds weakness in armor of killer hospital bacteria
10. Genetically engineered bacteria prevent mosquitoes from transmitting malaria
11. Modifying surfaces by means of nanostructured reliefs to prevent the spread of bacteria
Post Your Comments:
(Date:11/24/2015)...  Tikcro Technologies Ltd. (OTCQB: TIKRF) today announced that its Annual General ... a.m. Israel time, at the law offices of ... 36 th Floor, Tel Aviv, Israel . ... Izhak Tamir to the Board of Directors; , election ... , approval of an amendment to certain terms of options granted to ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... ... and the environment are paramount. Insertion points for in-line sensors can represent a ... developed the InTrac 781/784 series of retractable sensor housings , which are ...
(Date:11/24/2015)... Telbec/ - ProMetic Life Sciences Inc. (TSX: PLI) (OTCQX: PFSCF) ... Laurin , President and Chief Executive Officer of ProMetic, will ... 27 th Annual Healthcare Conference to be held at ... st , at 8.50am (ET) and ProMetic,s management ... The presentation will be available live via a webcast accessible ...
(Date:11/24/2015)... INCLINE VILLAGE, Nev. , Nov. 24, 2015  PDL ... John P. McLaughlin , the company,s president and chief ... Piper Jaffray Healthcare Conference next week in New ... and will occur on Tuesday, December 1, 2015 at 9:30 ... and Presentations." Please connect to the website at least 15 ...
Breaking Biology Technology:
(Date:11/11/2015)... , Nov. 11, 2015   MedNet Solutions , ... spectrum of clinical research, is pleased to announce that it ... Clinical Trials (PCT) event, to be held November 17-19 ... able to view live demonstrations of iMedNet ... learn how iMedNet has been able to deliver ...
(Date:11/10/2015)... About signature verification Signature ... identify and verify the identity of an individual ... secure and accurate method of authentication and is ... because each individual,s signature is highly unique. Signature ... signature of an individual is compared and matched ...
(Date:11/9/2015)... SAN JOSE, Calif. , Nov. 9, 2015 /PRNewswire/ ... of human interface solutions, today announced broader entry into ... of vehicle-specific solutions that match the pace of consumer ... drivers, and biometric sensors are ideal for the automotive ... the vehicle. Europe , ...
Breaking Biology News(10 mins):