THURSDAY, SEPTEMBER 29, 2016

C. difficile requires specific amounts of iron to grow--but not too much

C. difficile requires specific amounts of iron to grow | Courtesy of cdc.gov
A team of researchers recently discovered that Clostridium difficile, known as C. difficile, requires a specific amount of iron to grow, but too much iron will oxidize the bacteria.

Bacteria that need iron to grow can receive damage to their enzymes and DNA if they have too much iron. To outmaneuver this, specific machinery inside bacteria operates to maintain the bacteria’s intracellular iron level into a range that is most healthful for them. C. difficile has one of these machines, and the researchers hypothesized that studying it may help scientists develop better treatments for the illness.

Fur, or the Ferric-uptake regulator, is a compound proven to control the homeostasis of intracellular iron. C. difficile as well as other bacteria use Fur to repress iron-acquiring protein production as soon as there is enough iron in the environment.

The scientists created a mutant C. difficile without Fur. This helped them recognize the iron-importing proteins. The researchers discovered that C. difficile has many ways to important ferrous iron compounds, and the bacteria flourishes when it does not have oxygen.

The scientists concluded that this research most likely will not produce C. difficile therapeutics.

"We hypothesized that C. difficile must tightly control the production of its iron-acquisition mechanisms so that just the right amount of iron is brought into the bacteria," said Craig D. Ellermeier, an associate professor in microbiology at the University of Iowa.

"But in the long term," Ellermeier said, "if iron transport is critical one could imagine the development of drugs which would inhibit iron transport in C. diff.”

Further details are available in the printed edition of the Journal of Bacteriology, published by the American Society for Microbiology.