"It's almost as if the bacterium sense when to strike," said John Alverdy, corresponding author of the study and professor of surgery at the University of Chicago Medical Center. "That should come as no surprise since the bacteria are smart, having been around for 2 billion years."
Bacteria seek phosphate as an important nutrient, Alverdy explained. And rather than try to look for it in the blood steam of critically ill patients, where they would encounter armies of antibiotics and disease-fighting white blood cells, they find it inside organ tissues. This process damages and sometimes even kills their host.
Experiments with mice showed that the harm caused when P. aeruginosa becomes activated to express lethal toxins inside the intestinal tract can be mitigated by providing excess phosphate.
The research findings could lead to a pharmaceutical product that would restore healthy phosphate levels in the intestines of such stressed and compromised patients, Alverdy said.
"Antibiotics attempt to kill harmful bacteria, but in the process they often kill beneficial bacteria," said Olga Zaborina, an associate professor at the University of Chicagos Department of Surgery and another key researcher in this study. "A more sensible approach to fighting infectious diseases may be to try to understand the circumstances that provoke a microbe to cause harm in the first place and then find ways to pacify them without destroying them."
Containment on a case-by-case basis might be a more effective and longer-lasting strategy than a scorched earth policy, Alverdy said. Midway Pharmaceuticals, which Alverdy founded in 2005, is developing a pipeline of non-antibiotic compounds that contain or disarm specific bacteria.
Appreciation of the subtle mechanisms in pathogens that colonize the intestinal tract of
|Contact: Greg Borzo|
University of Chicago Medical Center