How do you study a pathogen that cant survive outside its hosts cells? In a new study published in the open access journal PLoS Biology, Hiroyuki Ogata and colleagues show that sequencing and analyzing the genome of the bacteria Rickettsia felis provide valuable insights into the biology and behavior of this intracellular pathogen. The researchers discovered that the parasitic bacterium has the standard large circular chromosome plus two unexpected plasmids, small circular pieces of DNA that can replicate on their own. This discovery may lead to novel techniques for study. "The newly identified plasmids may become a basis of a new tool, such as for efficiently producing rickettsial proteins," explains Ogata.
The common flea can carry Rickettsia felis bacteria in its cells
Other Rickettsia species include the pathogens responsible for typhus and Rocky Mountain spotted fever. "Up to now, due to the lack of appropriate genetic transformation tools for rickettsiae, detailed molecular studies were difficult for these bacteria," says Ogata. But with new tools and "because of the medical importance of this group of bacteria, different teams of researchers are sequencing the genomes of different species of Rickettsia felis. We determined the genome sequence of Rickettsia felis, which is the fourth Rickettsia genome completely determined." R. felis is the only species known to have a plasmid.
Ogata and colleagues also made surprising discoveries about sexual activity in these bacteria. The larger plasmid encoded proteins typically associated with bacterial sex, called conjugation. The researchers also observed pilli, the bacterial conjugation bridge. Previously, researchers believed that intracellular bacteria did not exchange genetic material with each other. But Ogata explains that the new findings "forced us to change this static view."
Paul Ocampo | EurekAlert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
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
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy