A large conjugative Acinetobacter baumannii plasmid carrying the sul2 sulphonamide and strAB streptomycin resistance genes
A large conjugative Acinetobacter baumannii plasmid carrying the sul2 sulphonamide and strAB streptomycin resistance genes
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DOI：
10.1016/j.plasmid.2016.09.001
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发表时间：
2016-09-01
期刊：
影响因子：
2.6
通讯作者：
Hall, Ruth M.
中科院分区：
文献类型：
--
作者：
Hamidian, Mohammad;Ambrose, Stephanie J.;Hall, Ruth M.
鲍曼不动杆菌是一种重要的医院内病原菌，由于其对抗生素的高度耐药，常使治疗复杂化。尽管质粒可以潜在地将各种基因引入细菌菌株，但与其他革兰氏阴性细菌相比，关于鲍曼不动杆菌独特的质粒库的信息有限。在这里，使用全基因组序列数据来确定菌株A297(RUH875)的质粒含量，该菌株是全球播散的多重抗性鲍曼不动杆菌克隆、全球克隆I(GC1)的参考菌株。A297含有三个质粒。其中一种是携带庆大霉素、卡那霉素和妥布霉素抗性基因的pA297-1(PREST*)，另一种是在GC1分离株中常见的8.7kb的隐匿质粒。第三个质粒pA297-3全长200kb，在Tn6172上携带硫磺酰胺抗性基因和链霉素抗性基因，在其他地方携带汞离子抗性模块。PA297-3高频地将磺胺、链霉素和汞离子抗性转移给敏感的鲍曼不动杆菌受体，并含有几个可能参与接合转移的基因。然而，没有发现松弛酶基因。它还包括几个编码蛋白质的基因，这些蛋白质与DNA新陈代谢有关，例如分区。然而，没有发现编码复制起始蛋白的基因。PA297-3包括一个小型反向重复序列转座元件(MITE)的两个拷贝，命名为MITE-297，包含一个77.5 kb的片段，包含多个IS和Mer模块。它们在不同的鲍曼无性系中被发现，并且分布广泛。它们都含有Tn6172或与pA297-3中的Tn6172位于同一主干位置的变异体。一些相关的质粒丢失了尘螨297拷贝之间的片段，只保留了一个尘螨-297。其他的在两个MITE-297拷贝之间有不同长度的片段，这些片段可以从pA297-3中的区域通过与IS26相关的缺失而得到，例如1S1007或IS1007-like。PA297-3及其近亲代表了第三种类型的接合不动杆菌质粒，有助于在该物种中传播抗生素耐药性。(C)2016 Elsevier Inc.保留所有权利。
Acinetobacter baumannii is an important nosocomial pathogen that often complicates treatment because of its high level of resistance to antibiotics. Though plasmids can potentially introduce various genes into bacterial strains, compared to other Gram-negative bacteria, information about the unique A. baumannii plasmid repertoire is limited. Here, whole genome sequence data was used to determine the plasmid content of strain A297 (RUH875), the reference strain for the globally disseminated multiply resistant A. baumannii clone, global clone I (GC1). A297 contains three plasmids. Two known plasmids were present; one, pA297-1 (pRAY*), carries the aadB gentamicin, kanamycin and tobramycin resistance gene and another is an 8.7 kb cryptic plasmid often found in GC1 isolates. The third plasmid, pA297-3, is 200 kb and carries the sul2 sulphonamide resistance gene and strAB streptomycin resistance gene within Tn6172 and a mer mercuric ion resistance module elsewhere. pA297-3 transferred sulphonamide, streptomycin and mercuric ion resistance at high frequency to a susceptible A. baumannii recipient, and contains several genes potentially involved in conjugative transfer. However, a relaxase gene was not found. It also includes several genes encoding proteins involved in DNA metabolism such as partitioning. However, a gene encoding a replication initiation protein could not be found. pA297-3 includes two copies of a Miniature Inverted-Repeat Transposable Element (MITE), named MITE-297, bracketing a 77.5 kb fragment, which contains several IS and the mer module.Several plasmids related to but smaller than pA297-3 were found in the GenBank nucleotide database. They were found in different A. baumannii clones and are wide spread. They all contain either Tn6172 or a variant in the same position in the backbone as Tn6172 in pA297-3. Some related plasmids have lost the segment between the MITE 297 copies and retain only one MITE-297. Others have segments of various lengths between two MITE-297 copies, and these can be derived from the region in pA297-3 via a deletion adjacent to IS related to IS26 such as 1S1007 or IS1007-like. pA297-3 and its relatives represent a third type of conjugative Acinetobacter plasmid that contributes to the dissemination of antibiotic resistance in this species. (C) 2016 Elsevier Inc. All rights reserved.