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通常认为多粘菌素是抵御多药耐受的革兰阴性病原菌严重感染的最后一道防线.最新研究表明在动物类食品和人体肠道菌群中存在一种多粘菌素抗性基因(mcr-1).这一发现对上述传统观点提出了严重挑战.更为惊讶的是,mcr-1基因可与其他抗生素抗性基因共存,极大增加了产生具有广泛耐药的超级细菌的可能性.但是,关于mcr-1阳性细菌的基因组学特征鲜见报道.本研究对3株mcr-1阳性人源大肠杆菌(E15004,E15015和E15017)开展了全基因组测序,并通过比较基因组学描述了其基因组学特征.基因组深入挖掘和序列分型实验揭示了序列型为ST648的大肠杆菌E15017不仅编码MCR-1多粘菌素耐药基因,而且携带超广谱β-内酰胺耐药(ESBL)基因.鉴于序列型ST648的大肠杆菌通常与新德里β-内酰胺耐药-1t(NDM-1)t或ESBL紧密关联这一事实,我们的研究结果提示了具有MCR-1和ESBL耐药的ST648细菌发展成流行性克隆的潜在风险.
Polymyxins are generally considered to be the last line of defense against severe infections with multi-drug resistant Gram-negative pathogens. Recent studies show that there is a polymyxin resistance gene (mcr) in animal food and human intestinal flora -1) .This finding poses a serious challenge to the traditional viewpoints mentioned above.More surprising is that the mcr-1 gene co-exist with other antibiotic resistance genes, greatly increasing the possibility of producing a broad-spectrum resistant superbugs However, there are few reports on the genomics of mcr-1-positive bacteria.In this study, genome-wide sequencing of three mcr-1 positive human Escherichia coli strains (E15004, E15015 and E15017) was carried out and compared by genomics Its genomics characteristics: Genomic digging and sequence typing experiments revealed that E. coli E15017 with sequence type ST648 not only encoded MCR-1 polymyxin resistance genes, but also extended-spectrum β-lactamase-resistant (ESBL) In view of the fact that the E. coli strain ST648 is usually closely associated with New Delhi’s beta-lactamase-resistant (NDM-1) or ESBL, our findings suggest that MCR-1 and ESBL resistant The drug ST648 bacteria developed into a pandemic Potential risk of sexual cloning.