Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genes involved in antibiotic resistance vary within a species

18.12.2008
Case Western Reserve University School of Medicine scientist leads comparative analysis of six genomes of Acinetobacter baumannii

The recent emergence of multidrug resistance (MDR) in Acinetobacter baumannii, a bacteria that causes infections primarily among seriously ill patients in the intensive care unit who may have reduced immune systems, has raised concern in health care settings worldwide.

When comparing the genome sequence of three MDR A. baumannii isolates and three drug-susceptible A. baumannii isolates, Case Western Reserve University School of Medicine found that one variation of bacteria would respond to antibiotics while another variation of the same bacteria may not.

A. baumannii is currently recognized by the Infectious Diseases Society of America as one of the most important pathogens threatening our health care delivery system.

Over the last 10-15 years, A. baumannii has become increasingly resistant to antibiotics and now more than one-third of infections are MDR, which means these pathogens are resistant to at least three different classes of antibiotics. This pattern of resistance to many antibiotics limits the ability of physicians to treat serious infections caused by A. baumannii.

The study, led by Mark Adams, Ph.D., Associate Professor in the Department of Genetics at Case Western Reserve University School of Medicine, is titled "Comparative Genome Sequence Analysis of Multidrug-Resistant Acinetobacter baumannii", and is in the December issue of the Journal of Bacteriology.

Adams first sequenced the genome of an MDR isolate and his collaborator in Buffalo, Steven Gill, Ph.D., Associate Professor of Oral Biology at SUNY Buffalo, sequenced two drug susceptible isolates to learn more about the genes (the genome contains the complete set of genes) that control resistance to antibiotics. Adams then compared the new sequence with genomes of other MDR and drug susceptible isolates, comparing six complete genomes.

What they found is that within a hospital or even a person, there can be a variation within the bacteria which means that it can affect how the infection reacts to antibiotics.

"A key conclusion of our study is that even very closely related isolates of A. baumannii can differ significantly in the set of resistance genes that they carry," said Adams. "It is known that resistance genes can be shared between bacteria (horizontal gene transfer), and it appears that this is a frequent event, with genes entering a genome and being deleted even across a single outbreak."

"We used to think—you treat this bacteria with this drug—but now we know that you have to look more carefully not just at the bacteria but at each one's genetic characteristics," said Adams. "This is an argument for targeted therapy in infectious disease because you want to select an antibiotic that will be effective against the particular genetic characteristics of the bug that's causing the infection."

The scientists also found that each isolate has a somewhat different set of genes.

"About three-fourths of the genes are shared by all the isolates, while the remainder are unique to different subsets," said Adams. "We identified 475 genes that are shared by all six clinical isolates of A. baumannii but are not present in a closely related Acinetobacter species that does not cause infections. These genes merit further study to help figure out what makes A. baumannii able to live in association with humans and cause disease."

Christina DeAngelis | EurekAlert!
Further information:
http://www.case.edu

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>