ヨーテボリ大学の研究では、廃水環境がこれまで考えられていたよりも抗生物質耐性の進化を促しており、耐性遺伝子が無害な細菌から病気を引き起こす細菌に移行することを可能にする独特の特性を備えていることが明らかになりました。 この研究は、新たな抗生物質耐性菌の出現を防ぐために、人や動物における抗生物質の使用を減らす努力と並行して、廃棄物の流れにも注意を払う必要性を強調しています。
スウェーデンのヨーテボリ大学の最近の研究によると、廃水における抗生物質耐性の進化の可能性は大幅に過小評価されています。 この研究により、廃水には、耐性遺伝子が無害な細菌から病気を引き起こす細菌へと旅を始めることを可能にする独特の特性があることが明らかになりました。
人間が抗生物質を薬として利用するずっと前に、微生物はすでにこれらの分子の生産を開発していました。 その結果、環境中の多くの細菌が抗生物質に耐性を示す能力が古くから備わっています。
ファニー・ベルグルンド、ヨーテボリ大学サーグレンスカ・アカデミー。 クレジット: ヨーテボリ大学
抗生物質が診療所に導入されて以来、病気の原因となる細菌も体内にますます多くの耐性遺伝子を蓄積し始めています。[{” attribute=””>DNA. This still ongoing process requires that genes, that were previously well anchored in the chromosome of certain bacterial species, first gain the ability to move around and eventually jump between species.
In a study published in the journal Communications Biology, researchers at the Centre for Antibiotic Resistance Research (CARe) in Gothenburg, Sweden present evidence for where the genes could gain their ability to move.
Important to prevent the emergence
It is known that wastewaters contain residues of antibiotics that could favor the development of antibiotic-resistant bacteria. New evidence shows that wastewaters also have characteristics allowing the resistance genes to start their journey from harmless bacteria to disease-causing bacteria.
The researchers acknowledged that it is not sufficient with antibiotics to drive the process. The species carrying the resistance genes in their chromosome also needs to be present, as well as specific sequences of DNA that could provide the ability to move the resistance genes.
By studying DNA from thousands of samples from different environments, the researchers could identify where all the key components came together. To the authors’ surprise, it was not in the gut of humans or animals, it was in wastewater sampled across the world.
“In order to fight antibiotic resistance we cannot focus only on preventing the spread of those types of resistant bacteria that are already in circulation, we also need to prevent or delay the emergence of new ones,” says Fanny Berglund, a researcher at the Sahlgrenska academy at University of Gothenburg, and the lead author of the study.
More focus on wastewater
The same research team has published several other studies showing that the environment harbors a huge variety of different resistance genes, many more than the resistance genes that we see today in bacteria causing disease.
This makes the environment a vast source for new resistance genes that one after the other acquire the ability to jump between species, to eventually end up in pathogens. The authors conclude that favoring this development by polluting the environment with antibiotics is not a good idea.
“There is a lot of focus on reducing antibiotic use in humans and animals. This is of course important, but our study shows that we also need to pay attention to our waste streams, as this seems to be a place where new variants of antibiotic resistance could emerge,” concludes Fanny Berglund.
Reference: “Evidence for wastewaters as environments where mobile antibiotic resistance genes emerge” by Fanny Berglund, Stefan Ebmeyer, Erik Kristiansson and D. G. Joakim Larsson, 25 March 2023, Communications Biology.
DOI: 10.1038/s42003-023-04676-7