They believe the combination of antibiotics will be successful when used in humans. Gautam Dantas, PhD, an associate professor of pathology and immunology, and the principal investigator in the study, said, “Using the drug combination to treat people has the potential to begin quickly because all three antibiotics are approved by the FDA.”

The three antibiotics in question — meropenem, piperacillin and tazobactam — are members of a broad class of drugs called beta-lactams that have proven to not be effective against MRSA when used alone.

Dantas’ team worked with scientists in the microbiology laboratory at Barnes-Jewish Hospital in St. Louis, testing and genetically analysing 73 different variants of the methicillin-resistant Staphylococcus aureus bacteria, including hospital-acquired and community-acquired forms of the pathogen.

The research had an exciting outcome. When the different variants of the MRSA bacteria were treated with a trio of the three drugs in test tubes, the antibiotics killed the bacteria every time. The next step was to test the combination of drugs in mice.

Dantas’ team then worked with researchers at the University of Notre Dame conducting experiments using mice infected with the different variants of the MRSA bacteria. The team found that the trio of antibiotics used to cure the mice was as effective as the strongest drug on the market.

“Without treatment, these MRSA-infected mice tend to live less than a day, but the three-drug combination cured the mice,” Dantas said. “After the treatment, the mice were thriving.” Dantas explained that the drugs attack the cell walls of the bacteria, and by working in a synergistic manner, they are more effective.

An important finding in the study was that the trio of drugs did not produce resistance in MRSA bacteria. The development of antibiotic-resistance has been a huge problem as more and more pathogens develop resistance to drugs that have in the past, been effective in treating infections.

“We started with MRSA because it’s such a difficult bug to treat,” Dantas said. “But we are optimistic the same type of approach may work against other deadly pathogens, such as Pseudomonas and certain virulent forms of E. coli.”