Study finds vast diversity among viruses that infect bacteria

March 24, 2016

Viruses that infect bacteria are among the most abundant life forms on Earth. Our oceans and soils, and potentially even our own bodies, would be overrun with bacteria were it not for bacteria-eating viruses—called bacteriophages—that keep the microbial balance in check.

Now, a new study at Washington University School of Medicine in St. Louis suggests that bacteriophages made of RNA - a close chemical cousin of DNA - likely play a much larger role in shaping the bacterial makeup of worldwide habitats than previously recognized.

The research, publishing on March 24 in the Open Access journal PLOS Biology, identifies 122 new types of RNA bacteriophages in diverse ecological niches, providing an opportunity to define their contributions to ecology, and potentially to fight bacterial infections, particularly those resistant to antibiotics.

"Lots of DNA bacteriophages have been identified, but there's an incredible lack of understanding about RNA bacteriophages," explained senior author David Wang, PhD, associate professor of molecular microbiology. "They have been largely ignored - relatively few were known to exist, and for the most part scientists haven't bothered to look for them. This study puts RNA bacteriophages on the map and opens many new avenues of exploration."

Wang estimates that of the more than 1,500 bacteriophages that have been identified, 99 percent of them have DNA genomes. The advent of large-scale genome sequencing has helped scientists identify DNA bacteriophages in the human gut, skin and blood as well as in the environment, but few researchers have looked for RNA bacteriophages in those samples.

First author Siddharth Krishnamurthy and the team, including Dan Barouch, MD, PhD, Beth Israel Deaconess Medical Center and Harvard Medical School, identified RNA bacteriophages by analyzing data from oceans, sewage, soils, crabs, sponges and barnacles, as well as insects, mice and rhesus macaques.

RNA bacteriophages have been shown to infect , which have become increasingly resistant to antibiotics and are the source of many infections in health care settings. But the researchers also showed for the first time that these bacteriophages may also infect gram-positive bacteria, responsible for strep and staph infections as well as MRSA.

"What we know about RNA bacteriophages in any environment is limited," Wang said. "But you can think of bacteriophages and bacteria as having a predator-prey relationship. We need to understand the dynamics of that relationship. Eventually, we'd like to manipulate that dynamic to use phages to selectively kill particular ."

Explore further: Viruses help scientists battle pathogenic bacteria and improve water supply

More information: Krishnamurthy SR, Janowski AB, Zhao G, Barouch D, Wang D (2016) Hyperexpansion of RNA Bacteriophage Diversity. PLoS Biol 14(3): e1002409. DOI: 10.1371/journal.pbio.1002409

Related Stories

Fighting bacteria—with viruses

July 24, 2014

Research published today in PLOS Pathogens reveals how viruses called bacteriophages destroy the bacterium Clostridium difficile (C. diff), which is becoming a serious problem in hospitals and healthcare institutes, due to ...

Viruses join fight against harmful bacteria

September 23, 2015

In the hunt for new ways to kill harmful bacteria, scientists have turned to a natural predator: viruses that infect bacteria. By tweaking the genomes of these viruses, known as bacteriophages, researchers hope to customize ...

Electrically induced arrangement improves bacteria detectors

December 10, 2015

Viruses that attack bacteria—bacteriophages—can be fussy:They only inject their genetic material into the bacteria that suit them. The fussiness of bacteriophages can be exploited in order to detect specific species of ...

Research team recognizes predator-producing bacteria

December 11, 2012

Unique viruses called bacteriophages may play an important role in competition among bacterial strains, influencing the overall ecosystem of the human intestine, scientists at The University of Texas at Arlington and UT Southwestern ...

Using viruses to beat superbugs

March 26, 2012

Viruses that can target and destroy bacteria have the potential to be an effective strategy for tackling hard-to-treat bacterial infections. The development of such novel therapies is being accelerated in response to growing ...

Recommended for you

Protein disrupts infectious biofilms

December 8, 2016

Many infectious pathogens are difficult to treat because they develop into biofilms, layers of metabolically active but slowly growing bacteria embedded in a protective layer of slime, which are inherently more resistant ...

The song of silence

December 8, 2016

Like humans learning to speak, juvenile birds learn to sing by mimicking vocalizations of adults of the same species during development. Juvenile birds preferentially learn the song of their own species, even in noisy environments ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.