可转移黏菌素耐药基因mcr:控制革兰阴性菌感染“最后一道防线”的严峻挑战

Mobile Colistin Resistance Gene(mcr):a Severe Challenge to the“Last-line Defense”of Gram-Negative Bacterial Infections

可转移黏菌素耐药基因(mobile colistin resistance,mcr)于2016年由中国学者首次报道,随后陆续在全球50余个国家及20余种宿主细菌中检测到10类43个突变体,其编码蛋白MCR具有2个保守的结构域和相似的预测蛋白结构,氨基酸序列相似性为32%~82.93%。研究发现,mcr可随宿主细菌在动物、人类和环境中广泛传播,严重降低了黏菌素这一控制兽医临床多重耐药革兰阴性菌感染“最后一道防线”的治疗效果及使用价值。mcr的全球传播可能基于其复杂的遗传背景,目前共发现14种阳性质粒,其水平转移也与插入序列ISApl1等众多可移动遗传元件有关。mcr在不同菌株甚至菌属间的传播已对全球公共卫生安全构成威胁,如何防控其传播尚需进一步关注。

Mobile colistin resistance(mcr)gene was first reported by Chinese scholars in 2016.Subsequently,43 mutants of 10 mcrs were detected in more than 50 countries and 20 host bacteria worldwide.The coding protein MCRs have two conserved domains and similar predictive protein structure,and the amino acid sequence homology is about 32%-82.93%.It was found that mcr can spread widely with host bacteria in animals,humans and the environment,seriously reducing the therapeutic efficacy and use value of colistin,the“last line of defense”to control multidrug-resistant Gram-negative bacterial infections in veterinary clinics.The global transmission of mcr may be based on its complex genetic background.A total of 14 positive plasmid-species have been identified so far,further more,the horizontal transfer of mcr is also related to many mobile genetic elements such as insertion sequence ISApl1.The horizontal dissemination of mcr among different bacteria and species is posing a global threat to the public health safety,and how to control the spread of mcr needs further attention.