新型抗生素抗性基因传播元件ISCR及其生态风险

抗生素抗性基因(antibiotic resistance genes, ARGs)作为一种新型的环境污染物，成为多个学科关注的焦点.其在不同环境介质中的扩散和传播具有极大的环境危害性，对人类健康造成严重威胁.插入序列共同区(insertion sequence common region, ISCR)，是一种新发现的抗性基因传播元件，因其特殊的遗传结构，能够通过滚环复制及同源重组等机制移动邻近的任何DNA序列，是ARGs在不同DNA分子或不同种属细菌间水平传播的高效媒介.目前世界上发现了27种ISCR元件.大量间接证据表明，ISCR可能与许多耐药基因的移动和扩散有关，特别是多重耐药性(multiple drug resistance, MDR)形成与传播.因此，ISCR很可能是抗生素抗性基因在环境中扩散传播的关键因子.本文就ARGs水平传播、ISCR结构特征、ISCR种类及其相关ARGs及其研究方法等进行综述，并揭示ISCR元件可能的生态风险，提出了今后的研究重点，以期为今后深入开展相关研究打下基础.

Novel transmission element of antibiotic resistance genes ISCR and its ecological risk.

Antibiotic resistance genes (ARGs) as emerging environmental pollutants have become the focus of attention of many disciplines. The transmission and dissemination of ARGs in various environmental media has great hazards to environment and poses serious threat to human health. ISCR (insertion sequence common regions) elements are newly discovered resistance genes transmission elements. Because of the special genetic structure, ISCR elements can move any adjacent DNA sequences by rolling circle replication and homologous recombination, and have become the efficient transmission elements of ARGs among different DNA molecules or bacterial species. Around the world, 27 members of the ISCR family have been discovered up to now. A lot of circumstantial evidence has indicated that ISCR elements may be associated with the mobility and transmission of kinds of ARGs, especially multiple drug resistance genes (MDR). In this review, we described some aspects of ISCR elements, including the horizontal transfer of ARGs, structural characteristics of ISCRs, classification of ISCRs and their related ARGs, research methods of these elements, possible ecological risk of ISCRs and proposal of research directions, hoping to provide help for further related research in the future.