中国9家三级医院产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌引起腹腔感染的分子特征
Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae causing intra-abdominal infections from 9 tertiary hospitals in China.
作者信息
Liao Kang, Chen Yili, Wang Menghe, Guo Penghao, Yang Qiwen, Ni Yuxing, Yu Yunsong, Hu Bijie, Sun Ziyong, Huang Wenxiang, Wang Yong, Wu Anhua, Feng Xianju, Luo Yanping, Hu Zhidong, Chu Yunzhuo, Chen Shulan, Cao Bin, Su Jianrong, Gui Bingdong, Duan Qiong, Zhang Shufang, Shao Haifeng, Kong Haishen, Xu Yingchun
机构信息
Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing 100730, China.
出版信息
Diagn Microbiol Infect Dis. 2017 Jan;87(1):45-48. doi: 10.1016/j.diagmicrobio.2016.10.007. Epub 2016 Oct 7.
BACKGROUND
Recently, the emergence of multidrug-resistant organisms such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has raised considerable concern regarding the appropriate treatment of intra-abdominal infections (IAIs). In this study, we investigated the molecular characteristics of ESBL among clinical isolates of Escherichia coli and Klebsiella pneumoniae causing IAIs and their pattern of antimicrobial resistance, which can provide useful information about the epidemiology and risk factors associated with these infections.
MATERIALS AND METHODS
One hundred sixty-seven E.coli and 47 K. pneumoniae ESBL-producing strains causing IAIs were collected from 9 hospitals in China, during 2012 and 2013. The antimicrobial susceptibility profile of these strains was determined. Polymerase chain reaction and sequencing were performed to identify genes for β-lactamase (blaTEM, blaSHV, blaOXA-1-like, and blaCTX-M). The isolates were also analyzed by pulsed-field gel electrophoresis (PFGE).
RESULTS
In 167 ESBL-producing E. coli strains, 104 strains (62.3%) were positive for CTX-M, and 9 strains (5.39%) were positive for SHV. Among the 47 K. pneumoniae strains, 35 strains (74.5%) were positive for SHV-2a, 12 strains (25.5%) were positive for CTX-M. No TEM-type and OXA-1-like strain was detected among all the ESBL-producing strains. Regarding the CTX-M-positive E. coli and K. pneumoniae strains, CTX-M-15 was the most common genotype in E. coli and K. pneumoniae strains, accounting for 28.7% and 17.0%, respectively, followed by CTX-M-55 accounting for 16.2% and 2.13%, respectively; the remaining genotypes included CTX-M-123 and CTX-M-82. PFGE showed that E.coli and K. pneumoniae ESBL-producing strains causing IAIs were diverse and that emerging resistance may not be due to the dissemination of national clones.
CONCLUSION
The present study revealed that in ESBL-producing strains causing IAIs in China, the most common genotype for E.coli was CTX-M-15 and for K. pneumoniae was SHV-2a. However, there was a wide diversity of strains causing IAIs among the ESBL-producing E. coli and K. pneumoniae.
背景
近年来，多种耐药菌的出现，如产超广谱β-内酰胺酶（ESBL）的肠杆菌科细菌，引发了人们对腹腔内感染（IAIs）恰当治疗的极大关注。在本研究中，我们调查了引起IAIs的大肠埃希菌和肺炎克雷伯菌临床分离株中ESBL的分子特征及其抗菌耐药模式，这可为这些感染相关的流行病学和危险因素提供有用信息。
材料与方法
2012年至2013年期间，从中国9家医院收集了167株引起IAIs的产ESBL大肠埃希菌和47株产ESBL肺炎克雷伯菌。测定了这些菌株的抗菌药敏谱。进行聚合酶链反应和测序以鉴定β-内酰胺酶基因（blaTEM、blaSHV、blaOXA-1-like和blaCTX-M）。还通过脉冲场凝胶电泳（PFGE）对分离株进行了分析。
结果
在167株产ESBL大肠埃希菌菌株中，104株（62.3%）CTX-M阳性，9株（5.39%）SHV阳性。在47株肺炎克雷伯菌菌株中，35株（74.5%）SHV-2a阳性，12株（25.5%）CTX-M阳性。在所有产ESBL菌株中均未检测到TEM型和OXA-1-like菌株。对于CTX-M阳性的大肠埃希菌和肺炎克雷伯菌菌株，CTX-M-15是大肠埃希菌和肺炎克雷伯菌菌株中最常见的基因型，分别占28.7%和17.0%，其次是CTX-M-55，分别占16.2%和2.13%；其余基因型包括CTX-M-123和CTX-M-82。PFGE显示，引起IAIs的产ESBL大肠埃希菌和肺炎克雷伯菌菌株具有多样性，新出现的耐药性可能并非源于国内克隆株的传播。
结论
本研究表明，在中国引起IAIs的产ESBL菌株中，大肠埃希菌最常见的基因型是CTX-M-15，肺炎克雷伯菌是SHV-2a。然而，产ESBL大肠埃希菌和肺炎克雷伯菌中引起IAIs的菌株具有广泛的多样性。
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