Zinc Plays Key Role

Hospital-acquired infections that are resistant to traditional antibiotic treatment have become increasingly common in recent years. The latest research results of University of Cincinnati (UC) scientists could lead to new ways to prevent this growing public health danger.

About two-thirds of all hospital-acquired infections in the United States can be traced to two staphylococcal species, Staphylococcus aureus - including methicillin-resistant strains (MRSA) that are particularly difficult to treat - and Staphylococcus epidermidis.

Researchers in UC's department of molecular genetics, biochemistry and microbiology detailed findings that the presence of zinc is crucial to the formation of infection-causing biofilms.

Staphylococci can grow as biofilms, which are specialized communities of bacteria that are highly resistant to antibiotics and immune responses. They are remarkably adhesive and can grow on many surfaces, including implanted medical devices such as pacemakers, heart valve replacements and artificial joints. Preventing or inhibiting the growth of such biofilms would dramatically reduce the incidence of staph infections.

UC researchers in the lab of 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.

The most practical applications, Herr says, might involve coatings for implanted medical devices, or rinses that a surgeon could use to clear the area around the implant.

Systemic removal of zinc, such as through an intravenous injection, is impractical for now because DTPA is approved by the U.S. Food and Drug Administration only for people with radio isotope poisoning. In addition, zinc is known to activate immune cells and play many other important roles in the body, so a proper balance would need to be developed.

COMPAMED.de; Source: University of Cincinatti