Zinc Found Effective Against Antibiotic-resistant Hospital-acquired Infections

by VR Sreeraman on Dec 6 2008 2:54 PM

Researchers at the University of Cincinnati (UC) in America have found that zinc plays a key role in hospital-acquired infections, which are resistant to traditional antibiotic treatment.

The researchers say that the presence of zinc is crucial to the formation of infection-causing biofilms.

About two-thirds of all hospital-acquired infections can be traced to two staphylococcal species, Staphylococcus aureus and Staphylococcus epidermidis, according to background information in an article published in the online edition of Proceedings of the National Academy of Sciences.

Staphylococci can grow as biofilms, which are specialized communities of bacteria that are highly resistant to antibiotics and immune responses. Since they are highly adhesive, they can grow on many surfaces, including implanted medical devices like pacemakers, heart valve replacements and artificial joints.

The UC researchers say that incidences of staph infections can be significantly reduced by inhibiting the growth of such biofilms.

Dr. Andrew Herr, an assistant professor and Ohio Eminent Scholar in structural biology, has discovered that zinc enables a protein on the bacterial surface to act like molecular Velcro, allowing the bacterial cells to stick to one another.

He also observed that the removal of zinc using an organic compound called diethylenetriamine pentaacetic acid (DTPA) prevented biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus.

"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," he says.

Given that zinc activates immune cells and plays many other important roles in the body, the researchers deem it impractical to use an intravenous injection to remove it, for it may disturb its balance.

Herr says that his lab will continue searching for a way to overcome this problem.