Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Sequencing Efforts Miss DNA Crucial to Bacteria’s Disease Causing Power

Published: Thursday, July 03, 2014
Last Updated: Thursday, July 03, 2014
Bookmark and Share
New research suggests that current sequencing protocols overlook crucial bits of information: isolated pieces of DNA floating outside the bacterial chromosome.

Genomic sequencing is supposed to reveal the entire genetic makeup of an organism. For infectious disease specialists, the technology can be used to analyze a disease-causing bacterium to determine how much harm it is capable of causing and whether or not it will be resistant to antibiotics.

“Extensive sequencing of chromosomal DNA has been performed for a variety of pathogenic organisms, but these sequences fail to uncover the presence of DNA elements in the cell’s cytoplasm. As a result, the DNA profile of a pathogenic bacteria may be incomplete,” says Vincent Fischetti, head of the Laboratory of Bacterial Pathogenesis and Immunology. “We have now devised a way to identify these elements.”

Extrachromosomal DNA can include bacteria-infecting viruses, known as phages, and strands of self-replicating DNA, known as plasmids, often picked up from other bacteria. These phages and plasmids can easily move between bacterial cells, and scientists have known for some time that, as a result, these so-called mobile genetic elements can play important roles in virulence and antibiotic resistance.

This study focused on phages. Their activity outside the chromosomes has been poorly studied; most research has focused on phages integrated into bacterial chromosomes. Meanwhile, plasmids, which allow bacteria to share genes among themselves, are well studied.

“So far, no one has looked across a variety of strains of bacteria, as we have done with Staphylococcus aureus, to find these extrachromosomal phages that have potential to play an important role in disease,” says Bryan Utter a postdoc in the lab and the first author of the research published June 25 in PLoS ONE. Staphylococcus is a common bacterium that can cause serious or even fatal infections under certain circumstances.

Until now, an analysis of this scope wasn’t possible, because chromosomal DNA easily fragments and contaminates the sample during the process by which researchers prepare the extrachromosomal DNA, making them virtually impossible to identify and sequence.

“To solve this problem, we borrowed a tool from phages themselves: the enzymes these viruses use to break apart a phage-infected cell to release their progeny,” says Douglas Deutsch, a graduate student in the lab. These enzymes, a focus of research in the lab in the development of novel anti-infectives, are now being harnessed to gently extract the chromosomal DNA, while leaving behind any other genetic elements for analysis. Using this technique, they looked for extrachromosomal phages across 24 medically important strains of Staphylococci.

Not only did extrachromosomal phages appear widespread among these strains, but the researchers found evidence that these phages encode genes that can make the bacteria more dangerous.

For example, when the researchers decoded the complete sequence of one extrachromosomal circular phage from a disease-causing Staphylococcus, they identified a number of genes that may help this strain evade a host’s immune system and that could readily spread to other Staphylococcus bacteria. The researchers are now studying what role, if any, these viral genes play in this strain’s ability to cause disease.

The implications go beyond pathogenicity. Phage elements, including those not integrated into chromosomes, are part of a bacterial system for regulating genes. For instance, some of these phage elements can activate or silence bacterial genes by moving into or out of the chromosome. Within the Staphylococcus strains, the researchers found both transient elements as well as those residing permanently outside the chromosomes.

“By examining the DNA outside the bacterial chromosomes, you may get a better understanding of the dynamics by which these elements may mobilize thereby controlling microbial genes,” Fischetti says.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,000+ scientific posters on ePosters
  • More Than 4,500+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Scientists Find Evidence That Cancer Can Arise Changes
Researchers at Rockefeller University have found a mutation that affects the proteins that package DNA without changing the DNA itself can cause a rare form of cancer.
Tuesday, May 24, 2016
Antibody Therapy Opens Door to Potential New Treatment for HIV
Researchers at Rockefeller University show how a broadly neutralizing antibody could be used to help fight HIV.
Wednesday, May 11, 2016
New Method Allows First Look At Embryo Implantation
Researchers at The Rockefeller University develop a method that shows the molecular and cellular processes that occur up to day 14 after fertilization.
Friday, May 06, 2016
How Evolution Formed the Nucleus
Long before animals evolved from sponges, and before plants evolved out of algae, there was a pivotal event that allowed complex, multicellular organisms to arise: the development of the nucleus in single-celled organisms.
Monday, March 21, 2016
Common Virus Depends on MicroRNA
In the ongoing arms race between pathogenic viruses and the cells they infect, each side needs every advantage it can get. One way wily viruses can get a leg up is by subverting the microRNAs (miRNAs) of their host.
Tuesday, March 15, 2016
Signals That Make Early Stem Cells Identified
Researchers at The Rockefeller University have identified a new mechanism by which cells are instructed during development to become stem cells
Tuesday, January 19, 2016
Skewed Expression of mRNA Fine Tunes of Protein Production
Long cast as a simple link between DNA and protein, messenger RNA has never offered much intrigue. But new research at The Rockefeller University suggests the molecule is up to something unexpected.
Friday, December 18, 2015
Fighting Sleeping Sickness
Researchers reveal method to manipulate trypanosomes in the mammalian bloodstream to acquire fly stage characteristics, a state that makes it easier for the host immune system to eliminate the invader.
Thursday, December 10, 2015
Study Explores How Molecules Are Speedily Transported Into and Out of The Nucleus
Researchers have identified the molecular mechanism that makes both swift and cargo-specific passage through the NPC possible for large molecules.
Tuesday, September 22, 2015
Promising Class of New Cancer Drugs Cause Memory Loss in Mice
New findings from The Rockefeller University suggest that the original version of BET inhibitors causes molecular changes in mouse neurons, and can lead to memory loss in mice that receive it.
Wednesday, August 26, 2015
Growing Hepatitis C in the Lab
Recent discovery allows study of naturally occurring forms of hepatitis C virus (HCV) in the lab.
Wednesday, August 26, 2015
Researchers Reveal Stomach Cancer Suppression Mechanism
A study reveals that the microRNA miR-7 suppresses gastric (stomach) cancer by inhibiting a key signaling pathway, and that this protective mechanism is compromised by the cancer-causing bacterium H. pylori.
Wednesday, August 12, 2015
Study Sheds Light on the Molecular Origins of Parkinson’s Disease
Researchers at The Rockefeller University and colleagues at Columbia University have identified two proteins they report may be important to Parkinson’s.
Wednesday, August 12, 2015
View of Bacterial Pump at the Atomic Level
Researchers have determined the structure of a simple but previously unexamined pump that controls the passage of proteins through a bacterial cell membrane, an achievement that offers new insight into the mechanics that allow bacteria to manipulate their environments.
Friday, July 24, 2015
A New Path Towards a Universal Flu Vaccine
New research suggests it may be possible to harness a previously unknown mechanism within the immune system to create more effective and efficient vaccines against this ever-mutating virus.
Friday, July 03, 2015
Scientific News
The Rise of 3D Cell Culture and in vitro Model Systems for Drug Discovery and Toxicology
An overview of the current technology and the challenges and benefits over 2D cell culture models plus some of the latest advances relating to human health research.
World’s Largest Coral Gene Database
‘Genetic toolkit’ will help shed light on which species survive climate change.
A Boost for Regenerative Medicine
Growing tissues and organs in the lab for transplantation into patients could become easier after scientists discovered an effective way to produce three-dimensional networks of blood vessels, vital for tissue survival yet a current stumbling block in regenerative medicine.
Breast Cancer Drug Hope
A drug for breast cancer that is more effective than existing medicines may be a step closer thanks to new research.
Untangling Disease-Related Protein Misfolding
Work advances understanding of genetic forms of thrombosis, emphysema, cirrhosis of the liver, neurodegenerative diseases and inflammation, among others.
Early Genetic Changes in Premalignant Colorectal Tissue Identified
Findings point to drivers of early cancer development, targets for cancer prevention therapies.
Harnessing Nature’s Vast Array of Venoms for Drug Discovery
Scripps scientists have developed a method for rapidly identifying venoms.
Nanoparticles Target, Transform Fat Tissue
Nanoparticles designed to target white fat and convert it to calorie-burning brown fat slowed weight gain in obese mice without affecting food intake. This proof-of-concept work could lead to new therapies to treat obesity.
New Cancer Fighters Emerge From Lab
Rice University lab simplifies total synthesis of anti-cancer agent.
Scientists Find Evidence That Cancer Can Arise Changes
Researchers at Rockefeller University have found a mutation that affects the proteins that package DNA without changing the DNA itself can cause a rare form of cancer.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,000+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,500+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!