Featured Research

from universities, journals, and other organizations

How do bacteria clog medical devices? Very quickly

Date:
March 1, 2013
Source:
Princeton University
Summary:
A new study demonstrates that bacteria can quickly and catastrophically clog medical devices by forming slimy ribbons that tangle and trap other cells.

Over a period of about 40 hours, bac­te­r­ial cells (green) flowed through a chan­nel, form­ing a green biofilm on the walls. Over the next ten hours, researchers sent red bac­te­r­ial cells through the chan­nel. The red cells became stuck in the sticky biofilm and began to form thin red stream­ers. Once stuck, these stream­ers in turn trapped addi­tional cells, lead­ing to rapid clog­ging.
Credit: Knut Drescher

A new study has exam­ined how bac­te­ria clog med­ical devices, and the result isn't pretty. The microbes join to cre­ate slimy rib­bons that tan­gle and trap other pass­ing bac­te­ria, cre­at­ing a full block­age in a star­tlingly short period of time.

Related Articles


The find­ing could help shape strate­gies for pre­vent­ing clog­ging of devices such as stents -- which are implanted in the body to keep open blood ves­sels and pas­sages -- as well as water fil­ters and other items that are sus­cep­ti­ble to con­t­a­m­i­na­tion. The research was pub­lished in Pro­ceed­ings of the National Acad­emy of Sciences.

Click on the image to view movie. Over a period of about 40 hours, bac­te­r­ial cells (green) flowed through a chan­nel, form­ing a green biofilm on the walls. Over the next ten hours, researchers sent red bac­te­r­ial cells through the chan­nel. The red cells became stuck in the sticky biofilm and began to form thin red stream­ers. Once stuck, these stream­ers in turn trapped addi­tional cells, lead­ing to rapid clog­ging. (Image source: Knut Drescher)

Using time-lapse imag­ing, researchers at Prince­ton Uni­ver­sity mon­i­tored fluid flow in nar­row tubes or pores sim­i­lar to those used in water fil­ters and med­ical devices. Unlike pre­vi­ous stud­ies, the Prince­ton exper­i­ment more closely mim­ic­ked the nat­ural fea­tures of the devices, using rough rather than smooth sur­faces and pressure-driven fluid instead of non-moving fluid.

The team of biol­o­gists and engi­neers intro­duced a small num­ber of bac­te­ria known to be com­mon con­t­a­m­i­nants of med­ical devices. Over a period of about 40 hours, the researchers observed that some of the microbes -- dyed green for vis­i­bil­ity -- attached to the inner wall of the tube and began to mul­ti­ply, even­tu­ally form­ing a slimy coat­ing called a biofilm. These films con­sist of thou­sands of indi­vid­ual cells held together by a sort of bio­log­i­cal glue.

Over the next sev­eral hours, the researchers sent addi­tional microbes, dyed red, into the tube. These red cells became stuck to the biofilm-coated walls, where the force of the flow­ing liq­uid shaped the trapped cells into stream­ers that rip­pled in the liq­uid like flags rip­pling in a breeze. Dur­ing this time, the fluid flow slowed only slightly.

At about 55 hours into the exper­i­ment, the biofilm stream­ers tan­gled with each other, form­ing a net-like bar­rier that trapped addi­tional bac­te­r­ial cells, cre­at­ing a larger bar­rier which in turn ensnared more cells. Within an hour, the entire tube became blocked and the fluid flow stopped.

The study was con­ducted by lead author Knut Drescher with assis­tance from tech­ni­cian Yi Shen. Drescher is a post­doc­toral research asso­ciate work­ing with Bon­nie Bassler, Princeton's Squibb Pro­fes­sor in Mol­e­c­u­lar Biol­ogy and a Howard Hughes Med­ical Insti­tute Inves­ti­ga­tor, and Howard Stone, Princeton's Don­ald R. Dixon '69 and Eliz­a­beth W. Dixon Pro­fes­sor of Mechan­i­cal and Aero­space Engineering.

"For me the sur­prise was how quickly the biofilm stream­ers caused com­plete clog­ging," said Stone. "There was no warn­ing that some­thing bad was about to happen."

By con­struct­ing their own con­trolled envi­ron­ment, the researchers demon­strated that rough sur­faces and pres­sure dri­ven flow are char­ac­ter­is­tics of nature and need to be taken into account exper­i­men­tally. The researchers used stents, soil-based fil­ters and water fil­ters to prove that the biofilm streams indeed form in real sce­nar­ios and likely explain why devices fail.

The work also allowed the researchers to explore which bac­te­r­ial genes con­tribute to biofilm streamer for­ma­tion. Pre­vi­ous stud­ies, con­ducted under non-realistic con­di­tions, iden­ti­fied sev­eral genes involved in for­ma­tion of the biofilm stream­ers. The Prince­ton researchers found that some of those pre­vi­ously iden­ti­fied genes were not needed for biofilm streamer for­ma­tion in the more real­is­tic habitat.

This work was sup­ported by the Howard Hughes Med­ical Insti­tute, National Insti­tutes of Health grant 5R01GM065859, National Sci­ence Foun­da­tion (NSF) grant MCB-0343821, NSF grant MCB-1119232, and the Human Fron­tier Sci­ence Program.


Story Source:

The above story is based on materials provided by Princeton University. Note: Materials may be edited for content and length.


Journal Reference:

  1. K. Drescher, Y. Shen, B. L. Bassler, H. A. Stone. Biofilm streamers cause catastrophic disruption of flow with consequences for environmental and medical systems. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1300321110

Cite This Page:

Princeton University. "How do bacteria clog medical devices? Very quickly." ScienceDaily. ScienceDaily, 1 March 2013. <www.sciencedaily.com/releases/2013/03/130301131127.htm>.
Princeton University. (2013, March 1). How do bacteria clog medical devices? Very quickly. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2013/03/130301131127.htm
Princeton University. "How do bacteria clog medical devices? Very quickly." ScienceDaily. www.sciencedaily.com/releases/2013/03/130301131127.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) — Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) — Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
In Japan, Robot Dogs Are for Life -- And Death

In Japan, Robot Dogs Are for Life -- And Death

AFP (Feb. 25, 2015) — Robot dogs are the perfect pet for some in Japan who go to repairmen-turned-vets when their pooch breaks down - while a full Buddhist funeral ceremony awaits those who don&apos;t make it. Duration: 02:40 Video provided by AFP
Powered by NewsLook.com
London Show Dissects History of Forensic Science

London Show Dissects History of Forensic Science

AFP (Feb. 25, 2015) — Forensic science, which has fascinated generations with its unravelling of gruesome crime mysteries, is being put under the microscope in an exhibition of real criminal investigations in London. Duration: 00:53 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins