Scientists study microbe filaments' power

Apr 18, 2008
Scientists study microbe filaments' power
An immunoflourescent image of a neisseria microcolony and its radiating pili. (Photo by Maggie So)

Researchers from The University of Arizona and Columbia University have discovered that tiny filaments on bacteria can bundle together and pull with forces far stronger than experts had previously thought possible.

The team of researchers, including Magdalene “Maggie” So, a member of the BIO5 Institute and the department of immunobiology in the UA College of Medicine, studied Type IV pili – or filaments – on the surface of Neisseria gonorrhoeae, the bacterium that causes the infectious disease gonorrhea. The research results help them understand the role that Type IV pili play in initiating a variety of infectious diseases – including tuberculosis – and how retracting pili allow bacteria to crawl and to exchange genes with each other.

When a bundle of Type IV pili retracts, it pulls with a force in the nanoNewton range, which is 10 times the force of a single retracting filament. The study demonstrates the power and cooperative nature of the nanomotors that cause Type IV pili to retract.

“The motor that causes these filaments to pull is one of the strongest nanomotors known in biology,” So said.

In previous studies, the same group of investigators measured single filament retraction forces in the 50 to 100 picoNewton range. This force allows the bacterium to move an object 10,000 times its own body weight. Retraction forces from a bundle are roughly 10 times higher, allowing the bacterium to move objects 100,000 times its body weight.

Pilus retraction forces are an important factor in how N. gonorrhoeae starts an infection. So, who has studied these microbes for more than 20 years, says N. gonorrhoeae communicates with a human cell by pulling on it. These pulling forces perturb the normal circuitry of the cell. As a result, the infected cell is fooled into lowering its defenses against the infecting microbe.

So said that the team of investigators came up with a new method to measure the tremendous forces applied by retracting pili. They allow bacteria to sit on a dense brushwork of tiny elastic pillars. The pili attach to these pillars. When pili retract, they bend the pillars. By measuring how the pillars bend, the investigators calculate the retraction forces.

Source: University of Arizona

Explore further: Population genomics unveil seahorse domain

add to favorites email to friend print save as pdf

Related Stories

Obama recommends extended wilderness zone in Alaska

23 hours ago

US President Barack Obama said Sunday he would recommend a large swath of Alaska be designated as wilderness, the highest level of federal protection, in a move likely to anger oil proponents.

NASA craft set to beam home close-ups of Pluto

23 hours ago

Nine years after leaving Earth, the New Horizons spacecraft is at last drawing close to Pluto and on Sunday was expected to start shooting photographs of the dwarf planet.

IBM disputes report that big layoffs coming

1 hour ago

IBM is pooh-poohing a published report that the giant technology company is planning a big reorganization and massive job cuts affecting more than 100,000 people.

Recommended for you

Population genomics unveil seahorse domain

4 hours ago

In a finding vital to effective species management, a team including City College of New York biologists has determined that the lined seahorse (Hippocampus erectus) is more a permanent resident of the we ...

Researchers develop new potato cultivar

7 hours ago

Dakota Ruby is the name of a new potato cultivar developed by the NDSU potato breeding project and released by the North Dakota Agricultural Experiment Station. Dakota Ruby has bright red skin, stores well and is intended ...

Researchers develop new soybean variety

7 hours ago

The North Dakota Agricultural Experiment Station has developed and released ND Henson, a conventional soybean variety, according to Rich Horsley, chair of the NDSU Department of Plant Sciences.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.