In vivo Emergence of Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae Mediated by Premature Termination of the mgrB Gene Regulator.
In vivo Emergence of Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae Mediated by Premature Termination of the mgrB Gene Regulator.
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mgrB 基因调节因子过早终止介导的耐碳青霉烯类肺炎克雷伯菌体内粘菌素耐药性的出现
DOI：
10.3389/fmicb.2021.656610
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发表时间：
2021
影响因子：
5.2
通讯作者：
Ruan Z
中科院分区：
文献类型：
--
作者：
Kong Y;Li C;Chen H;Zheng W;Sun Q;Xie X;Zhang J;Ruan Z
多药耐药肺炎克雷伯菌严重威胁着全球的公共健康。令人担忧的是，粘菌素耐药性是治疗耐多药肺炎克雷伯菌感染的最后一线抗生素之一，已有越来越多的报道。本研究旨在研究在粘菌素治疗过程中，对碳青霉烯类耐药肺炎克雷伯菌产生进化的粘菌素耐药性。在这项研究中，从同一患者身上分离到一对碳青霉烯类耐药肺炎克雷伯菌，分别命名为KP1-1和KP1-2。药敏试验采用微量肉汤稀释法。进行全基因组测序，并对两个分离株的基因组序列进行比较，分析可能的基因变异。用BacWGSTdb2.0服务器进行细菌全基因组序列分型和溯源分析。通过互补实验验证了这些变异在粘菌素耐药性中的作用。采用实时定量聚合酶链式反应(qRT-PCR)方法检测粘菌素抗性与Phop/PhoQ信号系统及其调控基因表达水平的关系。我们的研究表明，KP1-1具有广泛的抗生素耐药特性，但只对粘菌素敏感。KP1-2对粘菌素表现出额外的抗性。两株分离物均属于11号序列类型(ST11)。全基因组序列分析发现，两个分离物中都存在多个抗性基因和毒力基因。在粘菌素抗性分离物Kp1-2中，未检测到质粒介导的mcr基因，但检测到5个染色体基因的遗传变异，尤其是MgrB中的Gln30∗改变。此外，只有与野生型mgrB基因互补才能恢复粘菌素的敏感性，粘菌素MIC从32 mg/L降至1 mg/L。表达分析表明，与野生型分离株KP1-1相比，mgrB突变株KP1-2中Phop、PhoQ和pmrD基因过表达，证实MgrB突变是导致这些基因表达水平增加的原因。本研究提供了直接的体内证据，证明MgrB的Gln30∗改变是肺炎克雷伯菌临床分离株对粘菌素耐药的关键区域。
Multidrug-resistant (MDR) Klebsiella pneumoniae is a severe threat to public health worldwide. Worryingly, colistin resistance, one of the last-line antibiotics for the treatment of MDR K. pneumoniae infection, has been increasingly reported. This study aims to investigate the emergence of evolved colistin resistance in a carbapenem-resistant K. pneumoniae isolate during colistin treatment. In this study, a pair of sequential carbapenem-resistant K. pneumoniae isolates were recovered from the same patient before and after colistin treatment, named KP1-1 and KP1-2, respectively. Antibiotic susceptibility testing was performed by the microdilution broth method. Whole genome sequencing was performed, and putative gene variations were analyzed in comparison of the genome sequence of both isolates. The bacterial whole genome sequence typing and source tracking analysis were performed by BacWGSTdb 2.0 server. Validation of the role of these variations in colistin resistance was examined by complementation experiments. The association between colistin resistance and the expression level of PhoP/PhoQ signaling system and its regulated genes was evaluated by quantitative real-time PCR (qRT-PCR) assay. Our study indicated that KP1-1 displayed extensively antibiotic resistant trait, but only susceptible to colistin. KP1-2 showed additional resistance to colistin. Both isolates belonged to Sequence Type 11 (ST11). The whole genome sequence analysis uncovered multiple resistance genes and virulence genes in both isolates. No plasmid-mediated mcr genes were found, but genetic variations in five chromosomal genes, especially the Gln30∗ alteration in MgrB, were detected in colistin-resistant isolate KP1-2. Moreover, only complementation with wild-type mgrB gene restored colistin susceptibility, with colistin MIC decreased from 32 to 1 mg/L. Expression assays revealed an overexpression of the phoP, phoQ, and pmrD genes in the mgrB-mutated isolate KP1-2 compared to the wild-type isolate KP1-1, confirming the MgrB alterations was responsible for increased expression levels of those genes. This study provides direct in vivo evidence that Gln30∗ alteration of MgrB is a critical region responsible for colistin resistance in K. pneumoniae clinical strains.
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DOI：
10.1016/j.ijantimicag.2016.09.025
发表时间：
2016-12-01
影响因子：
10.8
作者：
Giamarellou, Helen
通讯作者：
Giamarellou, Helen
影响因子：
4.3
作者：
Wick, Ryan R.;Judd, Louise M.;Holt, Kathryn E.
通讯作者：
Holt, Kathryn E.
影响因子：
5.2
作者：
Olaitan AO;Morand S;Rolain JM
通讯作者：
Rolain JM
影响因子：
4.5
作者：
Lippa AM;Goulian M
通讯作者：
Goulian M
影响因子：
56.3
作者：
Liu, Yi-Yun;Wang, Yang;Shen, Jianzhong
通讯作者：
Shen, Jianzhong