Navigation Links
Together we stand: bacteria organize to survive hostile zones

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 Universitys Whiting School of Engineering and an affiliate of the university's Institute for NanoBioTechnology. When bacteria are under stresswhich is the story of their livesthey 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 teams findings were detailed in an article published in the November 2007 issue of the journal Public Library of Science Biology.

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 Groismans 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 Levchenkos 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 Chos 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 fibrosisa genetic disorder that affects the mucus lining of the lungsare susceptible to a species of bacteria that colonizes the lungs. Patients choke on the colonys 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.


Contact: Mary Spiro
Johns Hopkins University  

Related biology news :

1. Legionnaires bacterial proteins work together to survive
2. Shuttle brings space-grown strep bacteria back for study
3. The worlds oldest bacteria
4. Bacteria from sponges make new pharmaceuticals
5. Boston University biomedical engineers find chink in bacterias armor
6. University of Leicester scientists discover technique to help friendly bacteria
7. Spaceflight shown to alter ability of bacteria to cause disease
8. A tiny pinch from a z-ring helps bacteria cells divide
9. Scripps research team blocks bacterial communication system to prevent deadly staph infections
10. NSF awards Stevens team $1 million for research on smart, bacteria-repellent nanohydrogels
11. Chemical compound present in detergents produce bacteria alterations in agricultural soils
Post Your Comments:
Related Image:
Together we stand: bacteria organize to survive hostile zones
(Date:11/18/2015)... ALBANY, New York , November 18, 2015 /PRNewswire/ ... Transparency Market Research has published a new market report ... Share, Growth, Trends, and Forecast, 2015 - 2021. According to ... bn in 2014 and is anticipated to reach US$29.1 ... 2015 to 2021. North America ...
(Date:11/17/2015)... EASTON, Mass. , Nov. 17, 2015 ... a leader in the development and sale of broadly ... the worldwide life sciences industry, today announced it has ... of its $5 million Private Placement (the "Offering"), increasing ... to $4,025,000.  One or more additional closings are expected ...
(Date:11/12/2015)... Nov. 11, 2015   Growing need for ... tools has been paving the way for use ... of discrete analytes in clinical, agricultural, environmental, food ... predominantly used in medical applications, however, their adoption ... due to continuous emphasis on improving product quality ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... -- Cepheid (NASDAQ: CPHD ) today announced that ... and invited investors to participate via webcast. ... 1, 2015 at 11.00 a.m. Eastern Time --> ... 1, 2015 at 11.00 a.m. Eastern Time --> ... NY      Tuesday, December 1, 2015 at 11.00 ...
(Date:11/24/2015)... ... November 24, 2015 , ... International Society for Pharmaceutical Engineering ... premier annual events for pharmaceutical manufacturing: 2015 Annual Meeting. The conference took place ... the largest number of attendees in more than a decade. , “The ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... This fall, ... at competitive events in five states to develop and pitch their BIG ideas to ... from each state are competing for votes to win the title of SAP's Teen ...
(Date:11/24/2015)... Israel , Nov. 24, 2015  Tikcro Technologies Ltd. (OTCQB: TIKRF) ... on December 29, 2015 at 11:00 a.m. Israel ... Electra Tower, 98 Yigal Allon Street, 36 th Floor, ... of Eric Paneth and Izhak Tamir to the ... Rami Skaliter as external directors; , approval of an amendment to ...
Breaking Biology Technology: