Antibiotic resistance is a simple idea: Bacteria that might be expected to be wiped out by a drug are instead unaffected by it. But bacteria studied by a research group at Harvard University take the idea to a new level. With these bugs, what doesn’t kill them makes them thrive.
The researchers, led by George M. Church, a geneticist at Harvard Medical School, found hundreds of bacteria that can subsist on antibiotics as their sole source of carbon. They isolated strains from soils in 11 locations, including alfalfa fields in Minnesota and urban plots in Boston, and fed them 18 natural and synthetic antibiotics, including common ones like penicillin and ciprofloxacin. Bacterial growth was seen with almost all of them.
The researchers, who reported their findings in Science, say these microbes could be considered superresistant, since they can tolerate antibiotic concentrations that are 50 times the levels used to define bacteria as resistant.
None of the microbes studied by the team cause illness in people . And no human pathogens are known to have the ability to eat antibiotics.
But the findings represent an indirect threat to human health by showing that there’s a large reservoir of resistance in common bacteria in nature. And since bacterial resistance can be acquired through gene transfer, the possibility exists that human pathogens could pick up resistance from one of these relatives in the soil.
HENRY FOUNTAIN