The overlooked value of viruses - Keystone Symposia

material from the infecting bacteriophage, make copies of it and then insert it into an enzyme
complex designed to destroy genetic material. The captured genetic material then acts as a
template to guide the enzyme complex onto the bacteriophage genes and destroy them. In
other words, the bacteria use the bacteriophages’ own genetic material to target them with a
gene-seeking missile. This is a highly sophisticated and efficient protective mechanism. But it
has now emerged that some bacteriophages have hijacked the idea and developed a similar
mechanism, one that is targeted against their bacterial hosts. In particular, it was found that
bacteriophages which infect cholera-causing bacteria have acquired the technology to re-target
the degrading enzyme complex back onto bacterial genes responsible for controlling the antiviral
response. And so the race continues.
The potent anti-bacterial activity of bacteriophages has naturally led scientists to consider using
them as “natural” antibiotics. As early 1896, this idea arose when Ernest Hanbury Hankin
observed that water from the Ganges and Yamuna rivers in India was active against the cholera
bacteria. While those early attempts to use river water to cure disease were a little premature,
modern science offers tremendous hope for harnessing these viruses for good. It is important to
note here that bacteriophages are not able to infect human cells since the physiologies of
bacterial and human cells are very different. Therefore, bacteriophages would be very safe to
use in a clinical setting. Indeed, bacteriophages offer considerable hope in our own arms race
against the bacterial world, especially as we begin to run out of antibiotics against some types of
pathogenic bacteria. In addition to clinical applications, bacteriophages have been used to
control bacterial infections in a variety of food products, including meat and cheese, and they
have been considered as potential antidotes to bio-terror weapons containing the bacteria that
cause diseases such as anthrax.
While the potential benefits of bacteriophages are many, there are some negative aspects.
Biotechnology companies that rely on the mass culture of bacteria to produce products are
frequently impacted by bacteriophage infections. Even the dairy fermentation industry is
impacted, with bacteriophages causing significant problems in yogurt production. In an
evolutionary war, it seems you can’t win them all.
David L. “Woody” Woodland, Ph.D. is the Chief Scientific Officer of Silverthorne-based Keystone
Symposia on Molecular and Cellular Biology, a nonprofit dedicated to accelerating life science discovery
by convening internationally renowned research conferences in Summit County and worldwide. Woody
can be reached at 970-262-1230 ext. 131 or woody@keystonesymposia.org.