據(jù)一項新的研究報告稱，土壤細(xì)菌和人類病原體會快速地交換藥耐藥性基因,，提示環(huán)境中的細(xì)菌可促進(jìn)抗生素耐藥性危機(jī)。這些發(fā)現(xiàn)可改變目前的有關(guān)抗生素耐藥性及對付它的方法的想法,。土壤是地球上最大,、最多元的微生物生境之一；它被人們越來越多地認(rèn)識到是抗生素耐藥基因的一個巨大的來源,。土壤不但會直接與廣泛用于牲畜飼養(yǎng)和種植農(nóng)業(yè)的抗生素接觸,，它也是鏈霉菌的一個天然棲息地；鏈霉菌中的各種類型占了所有自然產(chǎn)生的抗生素中的主體,。Kevin Forsberg及其同事用元基因組測序來尋找與在沙門氏菌,、肺炎克雷伯菌及其它致病病原體等不同菌株中有著完全同一性的農(nóng)田土壤細(xì)菌中的7種抗藥基因。 他們還發(fā)現(xiàn),，多種抗藥基因簇集在一起并在其兩側(cè)有已知能夠使細(xì)菌之間發(fā)生基因轉(zhuǎn)移的移動DNA元件,。 盡管這一研究的設(shè)立并非是為了確定土棲生物體與人類病原體之間是如何交換基因的，但這些結(jié)果提示,，含有高濃度抗生素的排泄物對土壤和水的污染,，以及在牲畜飼養(yǎng)中過度使用抗生素可能是在環(huán)境細(xì)菌中出現(xiàn)抗生素耐藥基因選擇的促成因素。（生物谷Bioon.com）
doi: 10.1126/science.1220761
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The Shared Antibiotic Resistome of Soil Bacteria and Human Pathogens
Kevin J. Forsberg, Alejandro Reyes, Bin Wang, Elizabeth M. Selleck, Morten O. A. Sommer, Gautam Dantas
Soil microbiota represent one of the ancient evolutionary origins of antibiotic resistance and have been proposed as a reservoir of resistance genes available for exchange with clinical pathogens. Using a high-throughput functional metagenomic approach in conjunction with a pipeline for the de novo assembly of short-read sequence data from functional selections (termed PARFuMS), we provide evidence for recent exchange of antibiotic resistance genes between environmental bacteria and clinical pathogens. We describe multidrug-resistant soil bacteria containing resistance cassettes against five classes of antibiotics (β-lactams, aminoglycosides, amphenicols, sulfonamides, and tetracyclines) that have perfect nucleotide identity to genes from diverse human pathogens. This identity encompasses noncoding regions as well as multiple mobilization sequences, offering not only evidence of lateral exchange but also a mechanism by which antibiotic resistance disseminates.
