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.
The dissertation Survival strategies of Mycobacterium tuberculosis inside the human macrophage is published by LiU Electronic Press, It was publicly defended at Linköping University on March 4, 2011.
Contact:Amanda Welin: mobile phone: +46 (0)705-464749, email@example.com
Anika Agebjörn | idw
Make way for the mini flying machines
21.03.2018 | American Chemical Society
New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences