Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Too much of a good thing: Extra genes make bacteria lethal

11.02.2015

We, as most animals, host many different beneficial bacteria. Being beneficial to the host often pays off for the bacteria, as success of the host determines the survival and spread of the microbe. But if bacteria grow too much they may become deadly.

In a new study published in the latest edition of the scientific journal PLOS Biology*, a research team from Instituto Gulbenkian de Ciencia (IGC; Portugal) found that a single genomic change can turn beneficial bacteria into pathogenic bacteria, by boosting bacterial density inside the host.


This image shows small yellow dots surrounding bright yellow cell nuclei in each cell are Wolbachia. The cytoskeleton (in red) allows seeing the shape of the cells.

Credit: Ewa Chrostek (IGC)

Ewa Chrostek and Luis Teixeira studied the symbiosis between a fruit fly (Drosophila melanogaster) and the bacterium Wolbachia to answer how benign bacteria become pathogenic. Wolbachia is present in most insect species and protects some of them against viruses, including the dengue fever virus.

Previous studies conducted by Luis Teixeira's team showed that the number of Wolbachia inside the fruit fly determines its effect on the host. Bacteria that reach very high levels inside the fly become harmful. Hence, this research team set out to investigate the genetic basis that control bacteria density inside the host and, consequently, their pathogenicity.

Comparison of pathogenic and non-pathogenic Wolbachia variants suggested that the number of repeats of a specific region of the genome, called Octomom, was causing the difference in Wolbachia virulence. The authors show that the number of copies of this region was variable between individual flies.

The bacteria with more Octomom copies grow faster reaching higher densities inside the fruit flies. Consequently, the more copies, the earlier the flies die. On the other hand, more copies of the Octomom region and higher Wolbachia levels in flies provide stronger antiviral protection.

Ewa Chrostek, who just finished her PhD at Luis Teixeira's laboratory, says: "We show that Octomom copy number can change rapidly, leading to different Wolbachia infection outcomes for the fly. These bacteria can evolve really fast and easily break away from hosts' control."

Luis Teixeira explains further: "We discovered a region of the Wolbachia genome responsible for regulation of its densities in the flies. This is the first study linking genes and their functions in this bacteria and it provides a unique point of entry for the understanding of the widespread insect-Wolbachia symbiosis."

Currently, as part of a strategy to control dengue transmission, mosquitoes (Aedes aegypti) infected with Wolbachia bacteria are being released in the wild. Therefore, understanding mechanisms of potential Wolbachia evolution and Wolbachia densities control is extremely important.

###

This research was carried out at Instituto Gulbenkian de Ciencia (Oeiras, Portugal). This study was funded by Fundacao para a Ciencia e a Tecnologia (Portugal) and the Wellcome Trust (UK).

* Ewa Chrostek and Luis Teixeira (2015). Mutualism breakdown by amplification of Wolbachia genes. PLOS Biology.

Ana Mena | EurekAlert!

More articles from Life Sciences:

nachricht Cohesin down-regulation drives hematopoietic stem cell aging
14.12.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

nachricht Magic number colloidal clusters
13.12.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Foxes in the city: citizen science helps researchers to study urban wildlife

14.12.2018 | Ecology, The Environment and Conservation

Magic number colloidal clusters

13.12.2018 | Life Sciences

UNLV study unlocks clues to how planets form

13.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>