Zinc Zipper

A team of University of Cincinnati (UC) researchers is exploring a “zinc zipper” that holds bacterial cells together and plays a key role in such infections. It is hoped that these studies will lead to new ways to prevent this growing public health danger.

Researchers in UC’s department of molecular genetics, biochemistry and microbiology have found that the presence of zinc is crucial to the formation of infection-causing biofilms. Their findings appeared in the December 1st 2008 online edition of Proceedings of the National Academy of Sciences.

UC researchers working with Andrew Herr, PhD, an assistant professor and Ohio Eminent Scholar in structural biology, found that zinc causes a protein on the bacterial surface to act like molecular Velcro, allowing the bacterial cells in the biofilm to stick to one another. Zinc chelation, or removal, prevented biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus. The researchers used a chelation agent called DTPA (diethylenetriamine pentaacetic acid) to remove the zinc from a sample biofilm.

Herr explains, “We’ve shown that if you remove the zinc, you prevent the biofilm from forming, and if you add zinc back, the biofilm can grow. So we’re hopeful that we can use this sort of approach to prevent these biofilms from ever taking hold in the first place.”

The Evolution Of Medical Device Coatings

Staphylococci are remarkably adhesive and can grow on many surfaces, including implanted medical devices. These new findings could be used to develop new coatings for implanted medical devices, or rinses that a surgeon could use to clear the area around the implant.

Because DTPA is approved by the U.S. Food and Drug Administration only for people with radio isotope poisoning, systemic removal of zinc, such as through an intravenous injection, is currently impractical.

Read more about zinc removal fighting MRSA.