發(fā)布者：抗性基因網(wǎng) 時(shí)間：2023-06-12 瀏覽量：299
摘要
? ? ? 自然生活在生物膜中的水性細(xì)菌不斷暴露于藥物殘留物中，并定期釋放到淡水環(huán)境中。在源頭層面，抗生素排入河流已經(jīng)多次與抗微生物耐藥性的發(fā)展聯(lián)系在一起。但是遠(yuǎn)離排放點(diǎn)的生物膜呢？作為高收入和中等收入國(guó)家的典型代表，研究了兩條河流，這些河流的地點(diǎn)受到中等強(qiáng)度的分散污染。在河流原生巖石上形成的生物膜是環(huán)境暴露的完美代表。我們的研究結(jié)果表明，在遠(yuǎn)離熱點(diǎn)的地方，所研究的生物膜中抗生素的數(shù)量有利于維持和富集現(xiàn)有的耐藥菌株以及選擇新的耐藥突變體，并且這些有利條件會(huì)持續(xù)一段時(shí)間。因此，在這種類(lèi)型的河流中，選擇壓力的環(huán)境風(fēng)險(xiǎn)不僅存在于城市化地區(qū)的下游，而且也可能存在于污水處理廠排放的上游和下游。盡管如此，相關(guān)性分析發(fā)現(xiàn)抗生素濃度與所測(cè)整合素及其相應(yīng)抗性基因的豐度之間沒(méi)有強(qiáng)烈的正相關(guān)性。盡管如此，這項(xiàng)工作也強(qiáng)調(diào)了考慮抗生素在熱點(diǎn)以外的風(fēng)險(xiǎn)的必要性。
Abstract
Waterborne bacteria that naturally live in biofilms are continuously exposed to pharmaceutical residues, regularly released into the freshwater environment. At the source level, the discharge of antibiotics into rivers has already been repeatedly linked to the development of antimicrobial resistance. But what about biofilms away from the discharge point? Two rivers, with sites subject to dispersed contamination of medium intensity, were studied as typical representatives of high- and middle-income countries. The biofilms developed on rocks indigenous to rivers are perfectly representative of environmental exposure. Our results show that away from the hotspots, the amount of antibiotics in the biofilms studied favours the maintenance and enrichment of existing resistant strains as well as the selection of new resistant mutants, and these favourable conditions remain over a period of time. Thus, in this type of river, the environmental risk of selection pressure is not only present downstream of urbanized areas but is also possible upstream and far downstream of wastewater treatment plant discharges. Despite this, correlation analysis found no strong positive correlation between antibiotic concentrations and the abundance of measured integrons and their corresponding resistance genes. Nevertheless, this work highlights the need to consider the risks of antibiotics beyond hotspots as well.
https://www.sciencedirect.com/science/article/abs/pii/S0043135423000465