Featured Research

from universities, journals, and other organizations

Uncovering the secrets of tularemia, 'rabbit fever'

Date:
February 17, 2014
Source:
Biophysical Society
Summary:
Tularemia, aka "rabbit fever," is endemic in the northeastern United States, and is considered to be a significant risk to biosecurity -- much like anthrax or smallpox -- because it has already been weaponized in various regions of the world. Biologists are working to uncover the secrets of the bacterium Francisella tularensis, which causes tularemia.

The functions of novel proteins putatively involved in F. tularensis virulence are revealed by X-ray crystallography.
Credit: LLNL/G. K. Feld/CDC

Tularemia, aka "rabbit fever," is endemic in the northeastern United States, and is considered to be a significant risk to biosecurity -- much like anthrax or smallpox -- because it has already been weaponized in various regions of the world.

At the 58th Annual Biophysical Society Meeting, which takes place Feb. 15-19, 2014, in San Francisco, Calif., Geoffrey K. Feld, a Postdoctoral researcher in the Physical & Life Sciences Directorate at Lawrence Livermore National Laboratory (LLNL), will describe his work to uncover the secrets of the bacterium Francisella tularensis, which causes tularemia.

"Despite its importance for both public health and biodefense, F. tularensis pathogenesis isn't entirely understood, nor do we fully understand how the organism persists in the environment," explained Feld.

Previous efforts, funded by both the National Institutes of Health and LLNL, demonstrated that amoebae may serve as a potential reservoir for the bacteria in nature. "Specifically, we demonstrated that amoebae exposed to fully virulent F. tularensis rapidly form cysts -- dormant, metabolically inactive cells -- that allow the amoebae to survive unfavorable conditions," said Amy Rasley, the research team leader.

This encystment phenotype was rapidly induced by F. tularensis in the laboratory and was required for the long-term survival of the bacteria. Further exploration led to the identification of secreted F. tularensis proteins, which are responsible for induction of the rapid encystment phenotype (REP) observed in amoebae.

In the new work, Feld and colleagues characterized two of these REP proteins -- called REP24 and REP34 -- and began to describe their functions based on their three-dimensional crystal structures.

A big surprise finding was that these proteins resembled "proteases," which are proteins that cut other proteins in a specific manner. "Our preliminary data indicate that F. tularensis bacteria lacking these proteins are diminished in their ability to infect or survive in human immune cells, which indicates that these proteins may also contribute to F. tularensis virulence," Feld said.

Rasley and colleagues believe that careful characterization of these two novel F. tularensis proteins may shed light on how this organism persists in the environment and causes disease.

"Ultimately, this type of research could inform efforts to combat the disease, although there is much work to do. Currently, we don't know the protein targets in the host -- amoeba, human, etc. -- that the REP proteins act on, nor do we know the mechanism by which the proteins could help F. tularensis survive in the environment or cause disease," Feld said.

"Once these questions are elucidated, a broader understanding of environmental persistence and pathogenesis might lead to better diagnostics and/or novel countermeasures to combat tularemia," he added.


Story Source:

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


Cite This Page:

Biophysical Society. "Uncovering the secrets of tularemia, 'rabbit fever'." ScienceDaily. ScienceDaily, 17 February 2014. <www.sciencedaily.com/releases/2014/02/140217084808.htm>.
Biophysical Society. (2014, February 17). Uncovering the secrets of tularemia, 'rabbit fever'. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2014/02/140217084808.htm
Biophysical Society. "Uncovering the secrets of tularemia, 'rabbit fever'." ScienceDaily. www.sciencedaily.com/releases/2014/02/140217084808.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
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:
from the past week

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