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, firstname.lastname@example.org
Anika Agebjörn | idw
New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego
Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
17.01.2018 | Ecology, The Environment and Conservation
17.01.2018 | Physics and Astronomy
17.01.2018 | Awards Funding