Featured Research

from universities, journals, and other organizations

How tuberculosis bacteria manage to survive inside body’s macrophage cells

Date:
March 15, 2011
Source:
Expertanswer (Expertsvar in Swedish)
Summary:
Tuberculosis kills two million people each year. Researchers in Sweden are now presenting new findings that show how the bacterium that causes the disease manages to survive inside the body’s macrophage cells in order eventually to blow them up and spread their infection.

Tuberculosis kills two million people each year. Researchers at Linköping University in Sweden are now presenting new findings that show how the bacterium that causes the disease manages to survive inside the body's macrophage cells in order eventually to blow them up and spread their infection.

Related Articles


The bacterium Mycobacterium tuberculosis is a successful organism that lives in an estimated one third of the world's population. But only about five percent of those infected develop the disease.

"We also know that many people do not become infected despite exposure to the infection. This is a question we are looking for an answer to," says Amanda Welin, who is now presenting her doctoral dissertation in medical microbiology.

The research group has studied phenomena in both the bacterium and the macrophage, whose task is to knock out infectious substances that get into the body.

One weapon is enzymes, which make the ingested bacteria feel sickly. Enzymes work best in acidic environments, with a pH level under 6. For their part, the bacteria can strike back by releasing substances that prevent the pH level from going down. Amanda Welin has shown that this warfare is directly reflected in the growth or reduction of bacteria.

These bacteria also have a capacity to kill macrophages and spread to new cells. Welin shows that this is done by having a tiny protein cause cell death, necrosis, which in turn leads to inflammation of the tissue.

To carry out these studies, Amanda Welin and her colleagues developed a new method for determining the number of bacteria inside a cell. They use a gene from sea-fire organisms, which cause strange lights in seawater at night. When this gene is added to the genes of the bacterium, the bacterium begins to produce the same luminescent substance, luciferase, as the sea-fire organism does. Thanks to this, it's possible to monitor developments inside the macrophage -- the intensity of the light radiating outward corresponds to the number of bacteria inside. If their number grows, this indicates that they have begun to multiply inside the human cell.

The method can be used to search for plausible drug candidates. In that field, the Linköping scientists are collaborating with a group of colleagues in Sudan, who are testing, among other things, various medicinal plants with substances that could possibly be used as active ingredients to combat tuberculosis.


Story Source:

The above story is based on materials provided by Expertanswer (Expertsvar in Swedish). Note: Materials may be edited for content and length.


Cite This Page:

Expertanswer (Expertsvar in Swedish). "How tuberculosis bacteria manage to survive inside body’s macrophage cells." ScienceDaily. ScienceDaily, 15 March 2011. <www.sciencedaily.com/releases/2011/03/110309073940.htm>.
Expertanswer (Expertsvar in Swedish). (2011, March 15). How tuberculosis bacteria manage to survive inside body’s macrophage cells. ScienceDaily. Retrieved April 1, 2015 from www.sciencedaily.com/releases/2011/03/110309073940.htm
Expertanswer (Expertsvar in Swedish). "How tuberculosis bacteria manage to survive inside body’s macrophage cells." ScienceDaily. www.sciencedaily.com/releases/2011/03/110309073940.htm (accessed April 1, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, April 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Lion Makes Surprise Comeback in Gabon

Lion Makes Surprise Comeback in Gabon

AFP (Apr. 1, 2015) — The noble lion has made a comeback in southeast Gabon, after disappearing for years, according to US wildlife organisation Panthera, which recently took live video footage of a male. Duration: 00:32 Video provided by AFP
Powered by NewsLook.com
Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

AFP (Apr. 1, 2015) — The governments of Liberia and Sierra Leone have been busy fighting the menace created by the deadly Ebola virus, but illicit drug lords have taken advantage of the situation to advance the drug trade. Duration: 01:12 Video provided by AFP
Powered by NewsLook.com
Tracking This Warbler's 'Extraordinary' Transoceanic Flight

Tracking This Warbler's 'Extraordinary' Transoceanic Flight

Newsy (Apr. 1, 2015) — The blackpoll warbler makes one of the longest nonstop flights in the animal kingdom: three days straight for some 1,500 miles. Video provided by Newsy
Powered by NewsLook.com
Gorilla Falls Into Zoo Moat

Gorilla Falls Into Zoo Moat

Reuters - Light News Video Online (Mar. 31, 2015) — A gorilla comes to the rescue of her sister who fell into a moat in Israel&apos;s Safari zoo. Rough cut (no reporter narration). Video provided by Reuters
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