Thousands of illnesses attributed to Staphylococcus aureus infections could be prevented among hospitalized patients if doctors used medical devices coated with a peptide called RIP, according to new research published in the June 24th issue of the Journal of Infectious Diseases.

Staphylococcus aureus infections (Staph.) is a pathogen for numerous animal species and humans. There have been veterinary reports of methicillin-resistant (MRSA) infections in dairy herds with mastitis and in companion animals, said Naomi Balaban, PhD, assistant professor at Tufts School of Veterinary Medicine and an author of the study.

Currently veterinarians and human doctors rely on sterile tools and the use of antibiotics to limit and treat exposure to Staph. infections, though an increasing number of the infections are antibiotic-resistant. In humans, Staph. infections cause approximately 90,000 deaths in hospitals annually. In addition, mastitis is the most common and costly disease of dairy cattle worldwide.

Antibiotic therapies formulated for intra-mammary use are generally unsuccessful in eliminating S. aureus infections and preventing the establishment of chronic udder disease, Balaban said. "Moreover, with increasing public concern over food safety, there is regulatory pressure to use therapeutic drugs more judiciously in dairy cattle," she added. 

Balaban discovered the RIP molecule in 1993 while studying the way that bacteria recognizes neighbors. If a cell communicates or if bacteria senses another molecule it will produce toxins (like proteases) to help itself survive. She likened the scenario to several people sitting in a cramped room with a limited oxygen, space and food supply. During this process, she realized that RIP could prevent bacterial cell to cell communication.

 “The more of us there are the more suffocated we will feel and one of us will get up to open the window,” Balaban explained. Likewise, if the molecules of bacteria don’t sense each other (to open the door by use of one of the toxins) they will die, she said. “RIP interferes with the natural course of events."