Virulence and Genomic Feature of a Virulent Klebsiella pneumoniae Sequence Type 14 Strain of Serotype K2 Harboring bla(NDM-5) in China.
Virulence and Genomic Feature of a Virulent Klebsiella pneumoniae Sequence Type 14 Strain of Serotype K2 Harboring bla(NDM-5) in China.
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中国一株携带bla(NDM-5)的K2血清型肺炎克雷伯菌序列14型毒力及基因组特征
DOI：
10.3389/fmicb.2017.00335
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发表时间：
2017
影响因子：
5.2
通讯作者：
Cao XW
中科院分区：
文献类型：
--
作者：
Mei YF;Liu PP;Wan LG;Liu Y;Wang LH;Wei DD;Deng Q;Cao XW
本研究的目的是揭示K2肺炎克雷伯菌临床分离株24835对碳青霉烯类抗生素耐药和毒力的分子机制。通过体外和体内毒力测定方法对该菌株进行了毒力测定。采用全基因组测序技术和分子生物学方法，对克雷伯氏菌碳青霉烯类耐药和毒力相关基因组特征进行分析。pneumoniae 24835.菌株24835对碳青霉烯类抗生素高度耐药，属于ST 14，表现出高粘滞性和独特的K2-aerobactin-kfu-rmpA阳性表型。blaNDM-5是菌株24835中唯一的碳青霉烯酶基因，位于一个46-kb的IncX 3自传质粒上，该质粒与印度的pNDM-MGR 194非常接近。菌株24835中blaNDM-5的遗传背景与中国各种肠杆菌科物种中IncX 3质粒上的遗传背景密切相关。多个毒力基因的组合可能共同作用，赋予了克雷伯菌相对较高的毒力。pneumoniae 24835.产金属β-内酰胺酶（NDM）的新德里克雷伯氏菌对血清杀伤的抗性和小鼠死亡率显著增加。pneumoniae菌株与其他产NDM的K. pneumoniae菌株我们的研究提供了K的表型和基因组特征的基本信息。pneumoniae 24835是一株对碳青霉烯类抗生素耐药且毒力水平较高的菌株。这些发现是关于NDM样基因的潜力，传播之间的有毒K。肺炎分离株。
The objective of this study was to reveal the molecular mechanism involved in carbapenem resistance and virulence of a K2 Klebsiella pneumoniae clinical isolate 24835. The virulence of the strain was determined by in vitro and in vivo methods. The de novo whole-genome sequencing technology and molecular biology methods were used to analyze the genomic features associated with the carbapenem resistance and virulence of K. pneumoniae 24835. Strain 24835 was highly resistant to carbapenems and belonged to ST14, exhibited hypermucoviscous and unique K2-aerobactin-kfu-rmpA positive phenotype. As the only carbapenemase gene in strain 24835, blaNDM–5 was located on a 46-kb IncX3 self-transmissible plasmid, which is a very close relation of pNDM-MGR194 from India. Genetic context of blaNDM–5 in strain 24835 was closely related to those on IncX3 plasmids in various Enterobacteriaceae species in China. The combination of multiple virulence genes may work together to confer the relative higher virulence in K. pneumoniae 24835. Significantly increased resistance to serum killing and mice mortality were found in the virulent New Delhi metallo-β-lactamase (NDM)-producing K. pneumoniae strain compared to the other NDM-producing K. pneumoniae strain. Our study provides basic information of phenotypic and genomic features of K. pneumoniae 24835, a strain displaying carbapenem resistance and relatively high level of virulence. These findings are concerning for the potential of NDM-like genes to disseminate among virulent K. pneumoniae isolates.