What do intestinal bacteria tell us about drug resistance?

A bacterium found in leeches becomes resistant only after a small exposure to conventional antibiotics.

According to researchers on mBio on July 24, a bacterium found in leech intestines that only needs to touch 0.01 micrograms / ml of ciprofloxacin antibiotics will become resistant to this drug. Study co-author Joerg Graf, a biologist from the University of Connecticut in Storrs, said that the dose was less than the amount of antibiotics thought to cause resistance in the bacterium 400 times.

Certain leeches are approved for medical purposes by the US Food and Drug Administration to help patients recover from recovery surgery. These slimy creatures suck blood and secrete antifreeze, supporting tissue growth.

Contacting only a small amount of ciprofloxacin antibiotic is a leukemia that becomes resistant to this drug.

In the early 2000s, researchers noticed a small increase in antibiotic-resistant infections in these patients caused by Aeromononas bacteria , found at Hirudo Verbana, a leech species used medicinal. Scientists analyzed the intestinal substances by mass spectrometry, and found drug-resistant bacteria as well as small amounts of ciprofloxacin and enrofloxacin, a veterinary antibiotic used in poultry farms. . Researchers say leeches may have been exposed to these antibiotics through poultry blood used to feed leeches.

Graf suggested that leech farmers should remove ciprofloxacin and other antibiotics from their activities. But Aeromonas is also found in freshwater environments. He said: 'Very worrying because small amounts of antibiotics are detected in the environment.'

It is unclear whether Aeromonas alone has this low level of drug resistance, or whether other bacteria may also become less resistant. If so, it could cause problems for global efforts to prevent drug-resistant infectious diseases.