中文摘要：

最近,我国科学家发现一类由质粒携带的多黏菌素耐药新基因mcr-1.该基因随着细菌质粒在不同菌株之间水平转移,并赋予细菌抵抗多黏菌素类抗生素的能力.一旦MCR-1阳性细菌在全球蔓延,势必给＂全球公共卫生＂带来全新挑战,将意味着人类社会进入＂后抗生素＂时代.因此,mcr-1基因一经发现便引发全球关注,本文重点综述了MCR-1的全球分布和传播,携带该基因的质粒的多样性和复杂性以及MCR-1耐药性的生化机制等.希望通过加深对该基因的了解而寻求应对之策.

英文摘要：

Antibiotic resistance is becoming a global public health priority. The emergence of the notorious super-bugs that can produce the New Delhi β-1actamase 1 （NDM-1） had ever pushed us on the cusp of post-antibiotic era. The expression of NDM-1 （and its variants like NDM-5） allows the gut microbiota to gain the robust resistance to both extended spectrum β-1actamases （ESBL） and carbapenems, the two types of antibiotics extensively used for treatment of the multidrug- resistant bacteria. Colistin, referred to polymyxin E, belongs to a family of cationic polypeptide antibiotics, and acts as a final line of refuge against fatal infections by gram-negative pathogens with pan-drug resistance. Unfortunately, it seems likely that this last-resort antibiotics has been defied greatly by the appearance of colistin resistance. To the best of knowledge, three types of chemical modifications of the lipid A have been associated with the bacterial colistin resistance Generally, the lipid A anchor of lipid polysaccharide （LPS） can be modified with amine-containing substitutes including （i） addition of phosphoethanolamine to 4＇-phosphate position of sugar; （ii） modification of sugar with amino-arabinose at the 4＇-phosphate position; and （iii） glycine （and/or diglycine） modification at 3＇-linked secondary acyl chain. Consequently, the alteration of the LPS-lipid A moiety reduces the net negative charge of the bacterial outer-membrane, which in turn attenuates the binding of the cationic antimicrobial peptide colistin to bacterial surface. Thus, it is very true that divergent metabolic mechanisms are involved into bacterial colistin resistance. Very recently, a new mobilized colistin resistance gene （mcr-1） is reported by a research group in China. The transferability of the MCR-1 by gene horizontal transfer enables a variety of bacteria to be tolerant with the antibiotic polymyxin, a last line of resort against multi-drug resistant enterobacteria. The global dissemination of the MCR-1 might