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 Medical Center say.
A team led by Lora V. Hooper, an
associate professor of immunology
and microbiology at The University of Texas Southwestern Medical Center,
and including UT Arlington assistant professor of biology Jorge Rodrigues
examined the bacteriophages, or phages, produced by genetic information
harbored in the chromosome of the mammalian gut bacterium Enterococcus faecalis. They found that a phage unique to Enterococcus faecalis strain V583 in
mice acts as a predator, infecting and harming other similar, competing
bacterial strains. They believe these lab results suggest what goes on in the
“This organism is using phage as
a way to compete in your gut. If the phage is released and gets rid of all the
other microbes, then strain V583 will have more nutrients available,” Rodrigues
said. “It opens up new questions about the role of phages in the gut system.
Ultimately, you could use this as a technique to control bacteria in a natural
The findings were presented in
October in the Proceedings of the National Academy of Sciences in a paper
called, “A composite bacteriophage alters colonization by an intestinal
commensal bacterium.” It is available online here. Other
co-authors were members of Hooper’s lab: Breck A. Duerkop, Charmaine V.
Clements and Darcy Rollins.
“Now that we’ve established the
role of these bacteriophages, our team is working on trying to discover the
specific triggers that lead to phage production in the gut,” said Hooper, a Howard Hughes Medical Institute investigator.
“We also want to understand whether there are other phages that play a role in
shaping the composition of gut bacterial communities.”
Bacteria are abundant in the
human gastrointestinal tract, and scientists are increasingly trying to
understand their role in human health. Of those bacteria, Enterococcus faecalis, also known as E. faecalis, can constitute as much as 0.5 to 0.9 percent of gut
microflora, according to the researchers. Outside of the gut, E. faecalis can cause dangerous
infections, such as endocarditis, and is often resistant to standard
antibiotics like vancomycin.
The Ruth L. Kirschstein National
Research Service Award, The Howard Hughes Medical Institute, the National
Institutes of Health and the Burroughs Wellcome Foundation supported the work
described in the recent paper.
Rodrigues’s work is an example
of the collaborative science research going on at UT Arlington, a
comprehensive research institution of more than 33,200 students and more than
2,200 faculty members in the heart of North Texas. Visit www.uta.edu to
The University of Texas at Arlington is an Equal Opportunity and Affirmative Action employer.