Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Comparative genomics reveals molecular evolution of Q fever pathogen

04.02.2009
Scientists from the National Institute of Allergy and Infectious Diseases, Texas A&M Health Center, and the Virginia Bioinformatics Institute at Virginia Tech have uncovered genetic clues about why some strains of the pathogen Coxiella burnetii are more virulent than others.

The researchers compared the sequences of four different strains of C. burnetii, an intracellular bacterium that can cause acute and chronic Q fever in humans, to build up a comprehensive picture of the genetic architecture and content of the different genomes. The scientists examined C. burnetii strains of differing virulence to unveil clues on the genetic features associated with pathogenicity.

Q fever is considered one of the most infectious diseases in the world since inhalation of a single bacterium alone is sufficient to kick-start infection. Infection in humans typically results from contact with infected animals such as cattle, goats, and sheep. The C. burnetii bacterium targets macrophages — white blood cells in the body that usually provide protection against invading pathogens. The pathogen has the remarkable ability to replicate in a lysosome-like vacuole of macrophages, an extremely harsh intracellular environment that usually protects the body from infection by breaking down invading pathogens. The chronic form of Q fever in humans is rare but can lead to heart infections that are usually deadly if untreated.

Dr. Robert Heinzen, head of the Coxiella Pathogenesis Section at the National Institute of Allergy and Infectious Disease, remarked: "Our results suggest that mobile genetic elements have played a major role in the evolution and function of the C. burnetii genome. Recombination between insertion sequence elements or jumping genes appears to have brought about large-scale generation of non-functional genes, a change that may be associated with a more pathogenic lifestyle."

In the study, the researchers sequenced the genomes of three strains of the bacteria and made a four-way comparison of C. burnetii genomic sequences. Strain virulence was associated with a smaller genome. The loss of genes was due in part to the formation of pseudogenes, evolutionary remnants of earlier genes that no longer code for functional proteins.

Kelly Williams, research investigator at VBI, commented: "A principle of our and many modern studies was first enunciated in the title of a 1965 paper by Emile Zuckerkandl and Linus Pauling, 'Molecules as documents of evolutionary history'. Genomes are the ultimate molecular documents, filled with stories that fascinate and instruct, and we can now speed-read them."

VBI Executive and Scientific Director Bruno Sobral, a co-author on the paper, remarked: "2009 is the 200th anniversary of the birth of Darwin. That's a very suitable time to step back and think about how new technologies are giving us ever more powerful ways to investigate the history and mechanism of evolution. We hope the work in the current study serves as a resource for both the Coxiella and wider infectious disease research communities interested in the evolution of pathogen virulence."

Dr. Heinzen concluded: "The results of this study provide a solid foundation upon which we can test a number of hypotheses related to C. burnetii gene function and virulence. This information will prove invaluable as we proceed to dissect, at a molecular level, events associated with Q fever pathogenesis"

"Comparative genomics reveal extensive transposon-mediated genomic plasticity and diversity among potential effector proteins within the genus Coxiella" was published in the February issue of Infection and Immunity 77(2): 642-656.

Barry Whyte | EurekAlert!
Further information:
http://www.vbi.vt.edu

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>