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
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 2,400+ scientific posters on ePosters
  • More Than 3,700+ 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

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
Gene Editing Technique Mastered In Mosquito That Transmits Deadly Diseases
Technique will help researchers learn more about the role of genes that are involved in mosquito propagation.
Monday, March 30, 2015
Genetic Mutation Helps Explain Why, In Rare Cases, Flu Can Kill
Study shows that immune response to flu can be affected by a rare genetic mutation.
Monday, March 30, 2015
Changes In A Blood-Based Molecular Pathway Identified In Alzheimer’s
Study identifies increased activation of the contact system in plasma of Alzheimer’s patients.
Wednesday, March 25, 2015
Molecule Controls Stem Cell Plasticity By Boosting Gene Expression
Sox9 appears to lead the activation of super-enhancers that boost genes associated with stem cell plasticity.
Friday, March 20, 2015
microRNA’s Role as a Double Agent During Hep C Infection
Study suggests hepatitis C alters gene expression of infected cells by binding to miRNA-122.
Friday, March 13, 2015
Discovery Links Shift In Metabolism To Stem Cell Renewal
Mouse cells exposed to the metabolite alpha-ketoglutarate became more likely to renew themselves.
Wednesday, January 07, 2015
Single Gene Mutation Eliminates ISG15
Single gene links susceptibility to rare infections with predisposition to autoimmune disease.
Tuesday, October 14, 2014
How Developing Neurons Sense a Chemical Cue
An embryo organizes itself into left and right halves as it grows. But a certain set of nerve cells do something unusual: they cross from one side to the other.
Friday, May 30, 2014
High school project with DNA barcoding reveals what else is in your tea
Students found tea bags contain ingredients unlisted on the manufacturers’ package and included weeds such as annual bluegrass and herbal plants such as chamomile. The surprise ingredients are mostly harmless but could affect a tiny minority of consumers with acute allergies.
Thursday, July 21, 2011
Rockefeller to Receive State Money for Stem Cell Research
The Rockefeller University is one of 25 institutions to receive a combined $14.5 million from New York State to fund stem cell research and training.
Thursday, January 17, 2008
Initial Trigger is not Enough to Determine a Stem Cell’s Fate
Scientists have found that the bone morphogenetic protein pathway needs to be turned on and off at the right time and at the right place for adult skin stem cells to become hair follicles.
Thursday, August 09, 2007
MicroRNA Works with Ago2 Protein to Regulate Blood Cell Development
A Rockefeller University researcher has focused on understanding how microRNAs regulate the development of the hematopoietic system.
Friday, July 27, 2007
Immune response to Cancer Stem Cells may Dictate Cancer’s Course
A new study shows that immunity to cancer stem cells may help protect people with a precancerous condition from developing the full-blown disease.
Friday, March 30, 2007
Scientific News
Sorting Through Cellular Statistics
Aaron Dinner, professor in chemistry, and his graduate student Herman Gudjonson are trying to read the manual of life, DNA, as part of the Dinner group’s research into bioinformatics—the application of statistics to biological research.
Playing 'Tag' with Pollution lets Scientists See Who's It
Using a climate model that can tag sources of soot from different global regions and can track where it lands on the Tibetan Plateau, researchers have determined which areas around the plateau contribute the most soot — and where.
The Genetic Roots of Adolescent Scoliosis
Scientists at the RIKEN Center for Integrative Medical Sciences in collaboration with Keio University in Japan have discovered a gene that is linked to susceptibility of Scoliosis.
A Gene-Sequence Swap Using CRISPR to Cure Haemophilia
For the first time chromosomal defects responsible for hemophilia have been corrected in patient-specific iPSCs using CRISPR-Cas9 nucleases
Experimental MERS Vaccine Shows Promise in Animal Studies
A two-step regimen of experimental vaccines against Middle East respiratory syndrome (MERS) prompted immune responses in mice and rhesus macaques, report National Institutes of Health scientists who designed the vaccines.
New Tool Uses 'Drug Spillover' to Match Cancer Patients with Treatments
Researchers have developed a new tool that improves the ability to match drugs to disease: the Kinase Addiction Ranker (KAR) predicts what genetics are truly driving the cancer in any population of cells and chooses the best "kinase inhibitor" to silence these dangerous genetic causes of disease.
Understanding the Molecular Origin of Epigenetic Markers
Researchers at IRB Barcelona discover the molecular mechanism that determines how epigenetic markers influence gene expression.
HIV Susceptibility Linked to Little-Understood Immune Cell Class
High levels of diversity among immune cells called natural killer cells may strongly predispose people to infection by HIV, and may be driven by prior viral exposures, according to a new study.
Diagnostic Test Developed for Enterovirus D68
researchers at Washington University School of Medicine in St. Louis have developed a diagnostic test to quickly detect enterovirus D68 (EV-D68), a respiratory virus that caused unusually severe illness in children last year.
How a Kernel Got Naked and Corn Became King
Ten thousand years ago, a golden grain got naked, brought people together and grew to become one of the top agricultural commodities on the planet.
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
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!