The fungus, which is found in the soil, on plant debris and indoor air, is easily managed by the healthy immune system. But as medical advances contribute to a growing population of people whose immune systems are weakened by disease or treatment, the opportunistic fungus poses a serious risk.
Now, however, scientists may have found a master switch, an über gene, that seems to control the mold's ability to make poison. The new finding was reported today (April 12) in the journal Public Library of Science Pathogens by a team led by Nancy P. Keller, a biologist from the University of Wisconsin-Madison.
"There is a growing problem with medical fungi in the United States," says Keller, a UW-Madison professor of plant pathology and medical microbiology. "Aspergillus fumigatus is among the most important."
Like many fungi, Aspergillus fumigatus makes a variety of poisons, presumably to give the microbe a competitive advantage in the environments it inhabits. In humans with suppressed immune systems, the mold can cause a number of diseases with mortality rates of 60 percent or more.
"The infection can be treated, but not easily," Keller explains. "Once an immunocompromised individual gets any fungal disease, it's pretty hard to treat, and the treatments themselves are often toxic. There is a 60-90 percent mortality rate with invasive aspergillosis."
Thus, knowing how the fungus makes its chemical arsenal is important and opens an avenue to devising novel treatments that can disarm the pathogen before it does its dirty work.
In fungi, there are typically many genes at work making toxins and other chemical metabolites. The genes tend to be clustered in groups on the organism's genome. In Aspergillus fumigatus, there are as many as 22 such gene groupings.
How those posses of genes are triggered and governed, however, has been a mystery. But now Keller's group has found that a key gene known as LaeA controls at least half of those toxin-producing gene clusters, suggesting there may be a way to modulate the virulence of the deadly microbe.
"We now have a very good idea that (the gene) is central to the toxic nature of the fungus," Keller says.
The LaeA gene, she believes, is like a maestro, directing the mold's toxin-producing genes in an orchestrated chorus that, in the right host, can be fatal.
Knowing this, Keller explains, "suggests that if you can find a way to regulate the activity of LeaA you might have a novel target" for new therapies to treat Aspergillus fumigatus infection.
"The gene is not expressed all the time, which means there must be a signal that says 'turn me on.'"
Removing the gene from the equation, she says, may cripple the microbe's ability to infect and sicken people.
"The loss of LaeA results in a great decrease in the repertoire of secondary metabolites, which appears to impact the infection process," making the gene an ideal prospect for new ways to fight infection.
Nancy P. Keller | EurekAlert!
Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University
Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences