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Mechanical engineering in hot pursuit of creeping bacteria

Understanding how bacteria grows and spreads can help improve health care outcomes

Date:
September 7, 2016
Source:
University of Alberta
Summary:
The growth of bacterial biofilm is problematic when you think of all the liquid flowing through all those miles of tubing at your local hospital or Medi-Centre. The movement of bacteria with flow can lead to the spread of infection. A mechanical engineering professor's lab set out to study the formation of the filaments, as well as the conditions under which they begin to break down and finally break off.
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Image captures bacterial "Streamers" under flow conditions.
Credit: Aloke Kumar, UAlberta Engineering

University of Alberta mechanical engineering professor Aloke Kumar and members of his lab are hot on the trail of bacteria as they spread between surfaces connected by fluid flows. Understanding how this spread occurs is contributing to the development of prevention techniques and could improve our health and our healthcare practices.

Their research paper concerning the formation, deformation and breaking of microscopic streams of bacterial filaments in slo flowing fluids (creeping), written by Ishita Biswas, a PhD student in Kumar's lab, was published recently in Scientific Reports, a journal of the Nature Publishing Group.

Bacteria typically do not live in isolation, but live together in groups, encased in a matrix of self-secreted extra-cellular substances, called bio-films. When bacteria begin to make these biofilms in flowing, fluid conditions, the biofilms form as streamers -- slender filaments that grow longer and longer. Eventually, however, the filaments will break, and bacteria will float along with the flow of the fluid to new sites, bringing infection with them.

Such a problem is not insignificant when you think of all the liquid flowing through all those miles of tubing at your local hospital or Medi-Centre. Because this movement of bacteria with flow can lead to the spread of infection, or even just build up in pipes and tubes, Kumar's lab set out to study the formation of the filaments, as well as the conditions under which they begin to break down and finally break off.

"The complexity of the problem is created because of the extra-cellular substances that make up the streamers," says Kumar. "They have significant elasticity and they can unfold in different ways, so that when they're in a flow, the stress and strain

factors are not straight forward -- definitely not linear."

What's more, these streamers are very small and light-weight, because they have formed in such small devices. If, in order to study them, the researchers remove the streamers from the devices, they simply fall apart. In order to test them, therefore, Kumar and his lab members must work with the streamers inside these small devices.

Sometimes the smallest, slowest moving foes are the most formidable.


Story Source:

Materials provided by University of Alberta. Note: Content may be edited for style and length.


Journal Reference:

  1. Ishita Biswas, Ranajay Ghosh, Mohtada Sadrzadeh, Aloke Kumar. Nonlinear deformation and localized failure of bacterial streamers in creeping flows. Scientific Reports, 2016; 6: 32204 DOI: 10.1038/srep32204

Cite This Page:

University of Alberta. "Mechanical engineering in hot pursuit of creeping bacteria: Understanding how bacteria grows and spreads can help improve health care outcomes." ScienceDaily. ScienceDaily, 7 September 2016. <www.sciencedaily.com/releases/2016/09/160907160528.htm>.
University of Alberta. (2016, September 7). Mechanical engineering in hot pursuit of creeping bacteria: Understanding how bacteria grows and spreads can help improve health care outcomes. ScienceDaily. Retrieved May 28, 2017 from www.sciencedaily.com/releases/2016/09/160907160528.htm
University of Alberta. "Mechanical engineering in hot pursuit of creeping bacteria: Understanding how bacteria grows and spreads can help improve health care outcomes." ScienceDaily. www.sciencedaily.com/releases/2016/09/160907160528.htm (accessed May 28, 2017).

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