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!
Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Power and Electrical Engineering
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences