|
A
vampire-like bacteria that leeches onto specific other bacteria –
including certain human pathogens – has the potential to serve as a
living antibiotic for a range of infectious diseases, a new study
indicates.
The
bacterium, Micavibrio aeruginosavorus, was discovered to inhabit
wastewater nearly 30 years ago, but has not been extensively studied
because it is difficult to culture and investigate using traditional
microbiology techniques. However, biologists in the University of Virginia’s College of Arts & Sciences, Martin Wu and graduate student Zhang Wang, have decoded its genome and are learning “how it makes its living,” Wu said.
The
bacterium “makes its living” by seeking out prey—certain other
bacteria—and then attaching itself to its victim’s cell wall and
essentially sucking out nutrients. Unlike most other bacteria, which
draw nutrients from their surroundings, M. aeruginosavorus can survive
and propagate only by drawing its nutrition from specific prey bacteria.
This kills the prey—making it a potentially powerful agent for
destroying pathogens.
One
bacterium it targets is Pseudomonas aeruginosavorus, which is a chief
cause of serious lung infections in cystic fibrosis patients.
“Pathologists
may eventually be able to use this bacterium to fight fire with fire,
so to speak, as a bacterium that will aggressively hunt for and attack
certain other bacteria that are extremely harmful to humans,” Wu said.
His study, detailing the DNA sequence of M. aeruginosavorus, is published online in the journal BMC Genomics.
It provides new insights to the predatory lifestyle of the bacterium
and a better understanding of the evolution of bacterial predation in
general.
“We
used cutting-edge genomic technology in our lab to decode this
bacterium’s genome,” Wu said. “We are particularly interested in the
molecular mechanisms that allow it to hunt for and attack prey. This
kind of investigation would have been extremely difficult and expensive
to do only a few years ago.”
He
noted that overuse of traditional antibiotics, which work by either
inhibiting bacteria propagation or interfering with cell wall formation,
are creating so-called “super bugs” that have developed resistances to
treatment strategies. He suggests that new approaches are needed for
attacking pathogens without building up their resistance.
Martin Wu (left) and Zhang Wang. |
Additionally,
because M. aeruginosavorus is so selective a feeder, it is harmless to
the thousands of beneficial bacteria that dwell in the general
environment and in the human body.
“It
is possible that a living antibiotic such as M. aeruginosavorus—because
it so specifically targets certain pathogens—could potentially reduce
our dependence on traditional antibiotics and help mitigate the
drug-resistance problem we are now facing,” Wu said.
Another
benefit of the bacterium is its ability to swim through viscous fluids,
such as mucus. P. aeruginosavorus, the bacterium that colonizes the
lungs of cystic fibrosis patients, creates a glue-like biofilm,
enhancing its resistance to traditional antibiotics. Wu noted that the
living cells of M. aeruginosavorus can swim through mucus and biofilm
and attack P. aeruginosavorus.
M.
aeruginosavorus also might have industrial uses, such as reducing
bacteria that form biofilms in piping, and for medical devices, such as
implants that are susceptible to the formation of biofilms.
Wu
said M. aeruginosavorus requires further study for a more thorough
understanding of its gene functions. He said genetic engineering would
be required to tailor the predatory attributes of the bacterium to
specific uses in the treatment of disease.
“We have a map now to work with, and we will see where it leads,” he said.
Wu
and Wang’s co-author is Daniel E. Kadouri, a researcher at the New
Jersey Dental School. Kadouri is interested in M. aeruginosavorus as an
agent for fighting oral biofilms, such as plaque.
