Centre for Infectious Diseases and Microbiology, The University of Sydney, Westmead Hospital, Sydney, NSW 2145, Australia.
FEMS Microbiol Rev. 2011 Sep;35(5):820-55. doi: 10.1111/j.1574-6976.2011.00277.x. Epub 2011 Jun 16.
Antibiotic resistance in Gram-negative bacteria is often due to the acquisition of resistance genes from a shared pool. In multiresistant isolates these genes, together with associated mobile elements, may be found in complex conglomerations on plasmids or on the chromosome. Analysis of available sequences reveals that these multiresistance regions (MRR) are modular, mosaic structures composed of different combinations of components from a limited set arranged in a limited number of ways. Components common to different MRR provide targets for homologous recombination, allowing these regions to evolve by combinatorial evolution, but our understanding of this process is far from complete. Advances in technology are leading to increasing amounts of sequence data, but currently available automated annotation methods usually focus on identifying ORFs and predicting protein function by homology. In MRR, where the genes are often well characterized, the challenge is to identify precisely which genes are present and to define the boundaries of complete and fragmented mobile elements. This review aims to summarize the types of mobile elements involved in multiresistance in Gram-negative bacteria and their associations with particular resistance genes, to describe common components of MRR and to illustrate methods for detailed analysis of these regions.
革兰氏阴性菌的抗生素耐药性通常是由于从共享池中获得耐药基因。在多耐药分离株中，这些基因连同相关的移动元件，可能在质粒或染色体上的复杂聚集体中发现。对现有序列的分析表明，这些多耐药区域 (MRR) 是由有限数量的组件以有限的方式组合而成的模块化、镶嵌结构。不同 MRR 共有的组件为同源重组提供了目标，允许这些区域通过组合进化而进化，但我们对这一过程的理解还远远不够。技术的进步导致序列数据的数量不断增加，但目前可用的自动化注释方法通常侧重于通过同源性识别 ORFs 和预测蛋白质功能。在 MRR 中，基因通常特征明显，挑战在于准确识别存在的基因，并定义完整和碎片化移动元件的边界。本综述旨在总结革兰氏阴性菌多耐药性中涉及的移动元件类型及其与特定耐药基因的关联，描述 MRR 的常见组件，并举例说明分析这些区域的详细方法。
