Bacteria by antibiotics

Antibiotics work to kill bacteria, not to nourish them. But scientists at Harvard have discovered hundreds of bacteria in the soil that can take advantage of drugs as the sole source of nutrition and proliferate.

On the other hand, this work also explains why soil does not contain a large amount of biocides despite the use of drugs on pets as well as human wastes. According to microbiologist Jo Handelsman, University of Wisconsin-Madison, 'Luckily we have those bacteria to consume less antibiotics. Nature works effectively. '

The discovery was published in Science and was discovered by accident.

A research team led by Harvard Medical School geneticist George Church received a grant from the Department of Energy to develop ways to generate bioenergy from agricultural waste. Plants are full of natural toxins, so the goal of this work is to find microorganisms in the soil that are capable of breaking some of these chemicals. To identify the most potential candidates, they try to introduce bacteria into a much more toxic chemical: antibiotics.

Soil bacteria (Photo: Michael T. Holmes, Oregon State University, Corvallis)

The fact that bacteria can sometimes consume very strange things is the foundation for biological therapy. For example, some beetles help clean up oil spills. So it is not too surprising if the bacteria in the soil can withstand antibiotics, some species have been discovered. After all, some antibiotics are naturally derived like penicillin. Some drugs are also made from the soil.

Instead, the surprise is that many types of bacteria not only survive but also reproduce when raised with 18 different drugs, including natural and artificial - including substances such as getamicin, vancomycin and Cipro. - Mainly used in treating humans and animals. Church's team gathered land from 11 locations in Massachusetts, Minnesota and Pennsylvania, from city parks to wild forests and corn fields fertilized with antibiotic-containing fertilizers.

Bacteria like sugar, like ripe fruit. Only fed with antibiotics in laboratory plates, the bacteria grew a little slower but scientists found that all the drugs tested could support the development of some bacteria.

The annoying thing is that some bacteria can tolerate 50 to 100 times higher doses than patients."They are not only resistant, but super-resistant. I guess we never thought of the possibility that this would be a good bait for bacteria. They can live on this for a long time."

This finding raises concerns that many infectious diseases will soon be incurable, as more and more bacteria are immune to current antibiotics even though some new drugs are being processed. create.

But the medical impact of this new project is still unclear. Bacteria in the soil are not a major threat to humans and there is no source of infection for those who express this ability. However, many soil bacteria are tested as relatives with infectious sources, such as E. coli particularly dangerous.

So the next step, currently underway in Church's lab, is to identify the true genes that cause bacteria to consume and decompose antibiotics. Then the question will be about the possibility that the gene mechanism can turn to human sources, thus making them more resistant to the drug.

Handelsman argues that genes are more extensive and more complex than resistance to drugs because only one dominant gene is common in pathogens. And the Church agrees that his work 'is not entirely bad news. It gives us time to go ahead and find out if this is really a risk. '