Featured Research

from universities, journals, and other organizations

Anthrax Spores Use Failsafe Protection System, Say University Of Michigan Scientists

Date:
February 28, 2002
Source:
University Of Michigan Health System
Summary:
Protected by a tough outer coat that is impervious to cold, heat, drought and harsh chemicals, anthrax spores can remain dormant in the soil for decades. Once inside a living host, however, they can germinate and begin infecting cells in as little as ten minutes.

ANN ARBOR, Mich. -- Protected by a tough outer coat that is impervious to cold, heat, drought and harsh chemicals, anthrax spores can remain dormant in the soil for decades. Once inside a living host, however, they can germinate and begin infecting cells in as little as ten minutes.

Scientists know very little about what triggers an anthrax spore to break dormancy. Identifying the biochemical signals that start the process is an important first step to preventing anthrax infection.

A new study by University of Michigan scientists John A.W. Ireland, Ph.D., and Philip C. Hanna, Ph.D., shows that germination requires the coordinated activity of several genes, receptor proteins and amino acids in at least two simultaneous signaling pathways. The U-M study, published in the March 2002 issue of the Journal of Bacteriology, is the first to match anthrax genes with specific amino acids and signaling pathways that trigger germination.

"Anthrax doesn't rely on a single signal," says Hanna, an assistant professor of microbiology and immunology in the U-M Medical School. "Endospores have a redundant germination mechanism. It's the bug's way of ensuring that it won't lose its protective armor until conditions are right for germination."

Hanna and Ireland discovered that amino acids, the fundamental building blocks of all proteins in the body, in combination with purine ribonucleosides, the building blocks of DNA and RNA, are triggers for anthrax spore germination. The process appears to begin when receptor proteins on the spore's membrane bind to ring-shaped or aromatic structures on certain amino acids and ribonucleosides.

"The receptor protein is the lock and ring structures are the keys," says Ireland.

"The only place we know where all the required elements for germination are present is inside our cells, especially our phagocytes -- the scavenger cells of the immune system," Ireland explains. "But even in the macrophage where conditions are optimum for germination, the spore remains intact until at least two separate signaling pathways are activated."

Because it can be handled safely outside a high-level bio-containment laboratory, Hanna and Ireland used Sterne-based strains of anthrax in their research. The Sterne strain has been altered to remove dangerous infectious segments of the anthrax molecule called plasmids.

U-M scientists checked the genetic sequence of Sterne genes used in their study against the same genes in Bacillus anthracis Ames, the deadliest strain of anthrax, and found them to be a close match. B.anthracis gene sequences were provided by Tim Read, senior scientist at the Institute for Genomic Research (TIGR) in Rockville, Maryland.

Major findings of the study include:

Host signals from alanine and inosine were strong spore cogerminants when combined with other amino acids.

* Alanine was capable of triggering a strong, rapid germination response independently, but only when alanine concentrations were many times above normal cellular levels.

* Germinants vary depending on the anthrax bacterial species. Inosine is a strong independent germinant for B. cereus, but not for B. anthracis.

* A gene called gerS, present in both the Sterne strain and Ames strain of B.anthracis, appears to trigger two major signaling pathways. Similar genes have been found in other species of anthrax and may control germination in those species.

* Receptor proteins produced when the gerS gene is active respond specifically to the aromatic rings on certain types of amino acids and ribonucleosides.

In future research, Hanna will test these amino acids and ribonucleosides to see if they trigger anthrax spore germination in tissue cultures. Eventually, he hopes to expand the study to animal models. His research is supported by the National Institutes of Health and the Office of Naval Research.

Journal of Bacteriology, March 2002, p. 1296-1303, Vol. 184, No. 5

Editors: Full text of the published article is available on the ASM web site at: http://jb.asm.org/cgi/content/abstract/184/5/1296


Story Source:

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


Cite This Page:

University Of Michigan Health System. "Anthrax Spores Use Failsafe Protection System, Say University Of Michigan Scientists." ScienceDaily. ScienceDaily, 28 February 2002. <www.sciencedaily.com/releases/2002/02/020228072151.htm>.
University Of Michigan Health System. (2002, February 28). Anthrax Spores Use Failsafe Protection System, Say University Of Michigan Scientists. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2002/02/020228072151.htm
University Of Michigan Health System. "Anthrax Spores Use Failsafe Protection System, Say University Of Michigan Scientists." ScienceDaily. www.sciencedaily.com/releases/2002/02/020228072151.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

AP (Oct. 17, 2014) Two white lion cubs were born in Belgrade zoo three weeks ago. White lions are a rare mutation of a species found in South Africa and some cultures consider them divine. (Oct. 17) Video provided by AP
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
Sweet Times for Hard Cider Makers

Sweet Times for Hard Cider Makers

AP (Oct. 16, 2014) With hard cider making a hardcore comeback across the country, craft makers are trying to keep up with demand and apple growers are tapping a juicy new revenue stream. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Meet Garfi the Angry Cat

Meet Garfi the Angry Cat

Buzz60 (Oct. 16, 2014) Garfi is one frowny, feisty feline - downright angry! Ko Im (@koimtv) introduces us to the latest animal celebrity taking over the Internet. You can follow more of Garfi's adventures on Twitter (@MeetGarfi) and Facebook (Garfi). Video provided by Buzz60
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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