Harvard Study: Germs in soil thrive on antibiotics

A study just completed by Harvard geneticist, George Church, has discovered hundreds of germs that live in soil are thriving on antibiotics as their only source of nutrition, raising concern that, if dangerous pathogens were to develop this ability, they could render antibiotics useless.
These bacteria outwit antibiotics in a disturbingly novel way, and now the race is on to figure out just how they do it — in case more dangerous germs that sicken people could develop the same ability.

On the other hand, the work explains why the soil doesn't harbor big antibiotic buildups despite use of the drugs in livestock plus human disposal and, well, excretion, too.

The study, as reported last Friday in the journal, Science, was conducted by Harvard Medical School geneticist George Church as part of his Department of Energy grant to research the development of biofuels from agriculture waste; one of many research projects underway to determine if microbes have uses that range from alternative fuels to oil spill remediation.

The surprise was how many bacteria didn't just survive but flourished when fed 18 different antibiotics, natural and manmade ones — including such staples as gentamicin, vancomycin and Cipro — that represent the major classes used in treating people and animals.

The team used soil from parks, forests and antibiotic laden barnyards in Massachusetts, Minnesota and Pennsylvania, where they found the bacteria was able to absorb antibiotic levels up to 100 times more than would be prescribed to a human.

"They were not only resistant, they were super-resistant," Church said, "they are capable of living on this stuff for a long, long time."

The soil bearing germs have not, thus far, presented a danger to humans, although some are related to the e. coli strain. More studies are needed to determine if actual human pathogens, such as MERSA, have the same potential; a serious concern in light of their increasing antibiotic resistance of late.

One encouraging aspect is that the process required for the antibiotic consumption is more complex than the single-gene resistance seen in the human pathogens.

"It gives us some time to get ahead of it and figure out if it really poses a threat," Church explained.

More research is planned.