Study suggests spread of drug-resistant bacteria from people to nature

A group of researchers at institutions including Japan's Hokkaido University says a study has found that drug-resistant bacteria may be spreading from human society to aquatic environments and wildlife. It is calling for urgent preventive measures.

Bacteria that are resistant to antibiotics have become a serious problem both in Japan and abroad. Drug-resistant bacteria are said to be increasingly prevalent due to the overuse or misuse of antibiotics, such as patients stopping taking the drugs while germs remain in their body.

The focus of the group's research was the E.coli clone ST131, which has high levels of antibiotic resistance.

The group isolated ST131 from samples of lake and river water as well as the feces of wildlife, including raccoon dogs and deer, taken in prefectures including Gifu and Shiga for six years through 2021. The researchers then analyzed the genetic features.

They also analyzed ST131 isolates derived from the urine samples of people in the same region to compare the genetic background of the environmental isolates.

The analyses showed a close genetic similarity of ST131 between humans and aquatic environments and wildlife, suggesting the possible spread of the bacteria from human society to the natural world.

The group says it is the first time in Japan that the spread of drug-resistant bacteria has been shown based on genetic information.

The group warns that if no measures are taken, drug-resistant bacteria could spread further in nature and then from animals back to people, causing an outbreak of new infectious diseases.

Associate Professor Sato Toyotaka of Hokkaido University's Graduate School of Veterinary Medicine said he wants to identify how drug-resistant bacteria spread from people to the natural world and stop the spread.

The World Health Organization says antimicrobial resistance is one of the top global public health and development threats.

The WHO and other entities say antimicrobial resistant bacteria were responsible for an estimated 1.27 million global deaths in 2019. They could cause 10 million deaths a year by 2050 if no measures are taken.