Bacteria are divided into two types, gram-positive and gram-negative, with the primary difference being the nature of the bacterial cell wall. Little is known about how gram-positive bacteria—such as those that can lead to food poisoning, skin disorders and toxic shock—avoid being killed by AMPs. AMPs are made by virtually all groups of organisms, including amphibians, insects, several invertebrates and mammals, including humans.
“Gram-positive bacteria are major threats to human health, especially due to increasing problems with drug resistance, and these findings may help chart a path to designing new drugs to bolster our antimicrobial treatment options,” notes NIAID Director Anthony S. Fauci, M.D.
Led by Michael Otto, Ph.D., of NIAID’s Rocky Mountain Laboratories (RML), the scientists used the gram-positive bacterium Staphylococcus epidermidis to study its response to a specific human AMP, human beta defensin 3. S. epidermidis is one of several hard-to-treat infectious agents that can be transmitted to patients in hospitals via contaminated medical implants. Findings by Dr. Otto’s research group are published in the May 29 issue of the Proceedings of the National Academy of Science. Other well-known types of gram-positive bacteria include agents that cause anthrax, strep throat, flesh-eating disease and various types of food poisoning.
In gram-negative bacteria—such as those that cause plague and salmonellosis—a sensory and gene regulation system named PhoP/PhoQ protects invading bacteria, and scientists believe if they develop a better understanding of this system they could develop new drugs that are more effective at protecting people from infection.
Likewise, now Dr. Otto and his research group are hoping for similar possibilities for gram-positive bacteria with their discovery of “aps,” which stands for antimicrobial peptide sensor. Aps has three parts: apsS, the sensor region; apsR, the gene regulation region; and apsX, which has an unknown function that Dr. Otto’s group is investigating. Studies show that all three components of aps must be present for the system to function and effectively protect bacteria from AMPs.
“We are aware that for gram-negative bacteria, PhoP/PhoQ has been called a premier target for antimicrobial drug discovery, but little corresponding work has been done with gram-positive bacteria,” Dr. Otto says. “Our group is excited by what we have demonstrated—an efficient and unique way that gram-positive bacteria control resistance—and we are continuing our investigation of the aps sensing system being used for drug development.”
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