New compounds could restore antibiotic efficacy against superbug MRSA: study
Xinhua, March 10, 2016 Adjust font size:
Scientists said Wednesday they have successfully created compounds able to restore antibiotics' therapeutic efficacy against the methicillin-resistant Staphylococcus aureus (MRSA), one of the most notorious superbugs.
The compounds have no antimicrobial activity on their own, but become lethal when combined with existing antibiotics, offering a potential combination strategy against MRSA, they reported in the U.S. journal Science Translational Medicine.
MRSA poses a major public health crisis worldwide and is the second leading cause of death from drug-resistant bacterial infections in the United States.
The bacteria have grown resistant to the entire class of beta-lactam antibiotics, which includes penicillin and methicillin, creating an urgent need to develop new drugs or boost the efficacy of existing ones, according to researchers at the Merck Research Laboratories.
In the new study, they conducted a drug screen for inhibitors of wall teichoic acid, a major structural component of the bacterial cell wall that is thought to buffer MRSA against the antimicrobial effects of beta-lactams.
The researchers identified two synthetic compounds, which they named tarocin A and tarocin B, that block an enzyme that kickstarts wall teichoic acid production.
In culture, the compounds on their own had no effect on MRSA growth, but when paired with beta-lactams, killed various clinical strains of MRSA, they said.
While mice succumbed to MRSA infection when treated with either tarocin or beta-lactam alone, those treated with both drugs showed markedly reduced infection and improved survival.
"In conclusion, tarocins are an important new class of nonbioactive synthetic chemical inhibitors that are mechanistically suitable to serve as adjuvants when paired with existing b-lactam antibiotics, thus potentially restoring the therapeutic efficacy of this important class of antibiotics against methicillin-resistant staphylococci," their paper wrote. Enditem