Compound increases antibiotic effectiveness against MSRA

Researchers recently discovered a means of restoring the effectiveness of antibiotics to treat methicillin-resistant Staphylococcus aureus, a notoriously difficult to treat form of Staphylococcus.

Scientists from North Carolina State University have developed a compound that removes the bacteria's antibiotic resistance, making antibiotics once again effective at normal dosage levels, according to

NC State chemist Christian Melander previously worked with the compound to reactivate antibiotics against resistant bacterial strains, but the new research takes his work one step closer to in vivo testing.

"You measure antibiotic effectiveness by growing bacteria in the presence of an antibiotic," Melander said, reports. "The concentration you typically want to observe is about one microgram per milliliter or less of the antibiotic to halt bacterial growth. At that point the bacterial strain is considered susceptible to and treatable by that antibiotic.

"If a higher concentration of antibiotic is required to halt bacterial growth, the bacterial strain in question is considered untreatable. Some of the MRSA strains we work with require 512 micrograms per milliliter of the antibiotic of choice to control growth - 500 times over the limit. Adding our compound brought the level down to one microgram per milliliter again."

The compound works by disabling MSRA's ability to counter the antibiotic. Typically, once MSRA identifies a threat, it creates a biofilm or makes genetic changes to prevent the antibiotic from disrupting its cell structure. Melander said that his compound renders the bacteria unable to recognize the antibiotic as harmful, stopping any defense process before it can begin.