Antibiotics helps bacteria develop multi-drug tolerance
KU Leuven scientists have published a paper on the resistance of bacteria to antibiotics that goes beyond being resistant to one form of the drug
Because of overconsumption and misuse of antibiotics, said the researchers, resistant bacteria are increasingly common. But even when no resistant bacteria are involved, infections sometimes flare up again after a course of antibiotics. The scientists examined this phenomenon by treating the gut bacteria Escherichia coli with daily doses of antibiotics.
The researchers found that, although most bacteria were initially killed, some were able to very quickly adapt genetically. The result was the rapid development of many persister cells, which are tolerant to antibiotics. They survived the treatment and resumed reproduction afterwards. “Eventually, you end up with an entire population that is tolerant to several antibiotics,” said professor Jan Michiels in a statement.The researchers found that the number of tolerant cells in a population increases as bacteria are exposed to antibiotics more often: Daily doses have a bigger impact than weekly doses. Fortunately, the number of cells with multi-drug tolerance decrease again as soon as the antibiotic treatment ends.
“It’s common to screen for resistance during treatment with antibiotics, but not yet for tolerance,” said Michiels. “But as tolerant bacteria can go on to develop antibiotic resistance, it’s essential to figure out how and why more bacteria develop tolerance.”
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