Drug-Resistant ‘Superbugs’: Alternating Antibiotics May Help Suppress Deadly Bacteria, Study Finds

Scientists looking for new ways of combating the rise of drug-resistant “superbugs” in hospitals have found that alternating antibiotic treatments could prove effective in killing such deadly bacteria. Varying antibiotic use, as opposed to taking so-called antibiotic cocktails -- treatments containing multiple drugs in one -- could even stop bacteria from developing resistance in the first place, according to a new study published Wednesday in the journal PLOS Biology.

“Our study finds a complex relationship between dose, bacterial population densities and drug resistance,” Robert Beardmore, a researcher with the University of Exeter in the U.K. and lead author of the study, said in a statement. In test tube experiments, scientists found that the first drug administered to fight a bacterium “sensitized” the bug to the second treatment, making it more likely to be killed off. “As we demonstrate, it is possible to reduce bacterial load to zero at dosages that are usually said to be sub lethal and, therefore, are assumed to select for increased drug resistance,” said Beardmore.

Researchers have blamed the growing prevalence of drug-resistant superbugs on the over-prescription of antibiotics in North America and Europe. The overuse of such drugs, especially when taken for infections not treatable with antibiotics, promotes antibiotic resistance by allowing the stronger bacterium to survive and multiply, passing on its traits to the next generation. Over time, some bacteria stop responding to treatment altogether. Recent deadly outbreaks in U.S. hospitals of a superbug known as carbapenem-resistant Enterobacteriaceae, or CRE, put a spotlight on the threat posed by drug-resistant superbugs.

Despite the promising results of the recent University of Exeter study, scientists say more research is needed to develop new and better antibiotic treatments against superbugs. “One outcome of this highly surprising result will be to set in motion a series of studies to determine ways of using antibiotics not only in combination, but sequentially and with the potential for lower dosages than is currently thought possible,” Jessica Plucain, who was part of the research team that studied the alternating dose treatment, said in a statement.