发布者：抗性基因网 时间：2020-04-16 浏览量：850
摘要
背景：
整合子，尤其是1类整合子，是获得和传播抗生素耐药基因（ARGs）的主要因素。然而，对细菌类群中整合子的类型、含量和分布的全面了解还不足以评价它们的贡献。
结果：
我们构建了一个新的integrase数据库，并开发了一个管道，提供了1类整数的全面恢复。以前基于PCR的技术可能只检测到四分之一的整合子整合酶和整合子在本研究中恢复。通过对现有73000多个完整和草图细菌基因组中1类整合子的研究，评价了1类整合子在ARGs传播和获得中的作用。首先，1类整合子的宿主物种在Gammaprotobacteria中高度保守（96%），以四种致病性的“ESKAPE”为主；其次，超过一半的1类整合子嵌入染色体中，水平基因转移的可能性较小。最后，这些整合子获得的ARGs只覆盖了细菌基因组中所有精氨酸基因型的11%。
结论：
上述观察结果表明，1类整合子在不同种类的域细菌中获得和传播arg既有生物学上的限制，也有生态学上的限制。
Integrons, especially the class 1 integrons, are major contributors to the acquisition and dissemination of antibiotic resistance genes (ARGs). However, comprehensive knowledge of the types, content, and distribution of integrons in bacterial taxa is lacking to evaluate their contribution.
We have constructed a new integrase database and developed a pipeline that provides comprehensive recovery of class 1 integrons. Previous PCR-based techniques might only detect one fourth of the integron-integrases and integrons recovered in this study. By exploring the class 1 integrons in over 73,000 currently available complete and draft bacterial genomes, the contribution of class 1 integrons in spreading and acquiring ARGs was evaluated. Firstly, the host species of class 1 integrons are highly conserved within (96%) in class Gammaproteobacteria, dominated by four pathogenic species of "ESKAPE." Secondly, more than half of class 1 integrons are embedded in chromosomes with less potential for horizontal gene transfer. Finally, ARGs that have been acquired by these integrons only cover 11% of all the ARG genotypes detected in bacterial genomes.
The above observations indicated that there are both biological and ecological limitations to class 1 integrons in acquiring and spreading ARGs across different classes of the domain Bacteria.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6054849/