Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Resistance to antibiotics: When 1+1 is not 2

27.07.2009
Genetic interactions underlie multi-resistant bacteria

The evolution of multiple antibiotic resistances is a global and difficult problem to eradicate.

Isabel Gordo, a group leader at the Instituto Gulbenkian de Ciência (IGC)- Portugal, reports in the paper published in the latest issue of PLoS Genetics (*), that the deleterious effect associated with the acquisition of resistance by a bacteria can be suppressed by the acquisition of a new resistance to another antibiotic. These findings have direct implications for the approaches taken to tackle the problem of multi-resistance to antibiotics and in the choice of antibiotics to be administrated to patients.

Acquisition of mutations is one of the ways by which bacteria become resistant to antibiotics. But this comes with a cost: although crucial for bacteria survival in a medium with antibiotics, in its absence bacteria growth rate is reduced. Although it is not possible to impaired bacteria to evolve and adapt to the environment, it is possible to choose the type of selective pressure (antibiotics) to administrate and, in this way, alter the course of evolution to our favour. This study shows the importance of knowing the costs of multi-resistance to find the best antibiotic combinations (the ones that carry more costs to the bacteria).

In collaboration with two other research groups at the IGC, Isabel's team selected populations of the bacteria, Escherichia coli, showing spontaneous mutations that confer resistance to common used antibiotics (the same used in the treatment of tuberculosis). This approach allowed the team to measure the effect of genetic interactions – a phenomenon scientists call epistasis- between the alleles of the genes involved in resistance. Epistasis is considered to be one of the key issues in Biology research.

Isabel describes their findings, 'To our surprise, when in a medium without antibiotics, bacteria that are carry resistance to two drugs have a higher survival rate than expected, showing a smaller cost to multiple resistance". Even more surprisingly, in some combinations (12%) the double mutants to two given antibiotics survive even better than if they were resistant to only one of the drugs. This is the worst scenario case for the host (including our species) and the best for the bacteria.

This study provides the first insight into the importance of genetic interaction between random alleles in determining antibiotic resistance in bacteria. From a public health point of view, it can also explains multi-drug resistance seen in bacteria associated with many diseases, such as tuberculosis (Mycobacterium tuberculosis), for which current treatments involve combinations of the same drugs used in this study.

According to Isabel: "This works shows how important it is to know the clinical history of the patient's antibiotic use as well as the specific bacteria's genotype associated with a given resistance in order to choose the appropriate treatment and obtain the best clinical outcomes". She adds: "From a more general point of view, this work uncovers the complexity associated with genomes ".

(*)Trindade S, Sousa A, Xavier KB, Dionisio F, Ferreira MG, Gordo I(2009) Positive Epistasis Drives the Acquisition of Multidrug Resistance. PLoS Genet 5(7): e1000578. doi:10.1371/journal.pgen.1000578

(When published on July 24, the paper will be accessible at the following link: http://www.plosgenetics.org/doi/pgen.1000578)

Silvia Castro | EurekAlert!
Further information:
http://www.igc.gulbenkian.pt

More articles from Life Sciences:

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>