Abrupt Emergence of a Single Dominant Multidrug-Resistant Strain of Escherichia coli
Abrupt Emergence of a Single Dominant Multidrug-Resistant Strain of Escherichia coli
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DOI：
10.1093/infdis/jis933
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发表时间：
2013-03-15
影响因子：
6.4
通讯作者：
Sokurenko, Evgeni V.
中科院分区：
文献类型：
--
作者：
Johnson, James R.;Tchesnokova, Veronika;Sokurenko, Evgeni V.
背景资料。对氟喹诺酮类药物耐药的大肠杆菌日益流行。它们的克隆起源--可能对控制工作至关重要--仍未确定。对来自西雅图、华盛顿州和明尼苏达州5个临床实验室的236株不同来源的历史(1967-2009年)大肠埃希菌代表序列类型ST131的236株和近期(2010-2011年)连续分离的853株大肠埃希菌进行了耐药谱和精细克隆结构的测定。根据fimH序列(菌毛粘附素基因：H亚克隆分配)、多位点序列分型、gyrA和parc序列(氟喹诺酮类药物耐药决定基因)和脉冲场凝胶电泳法解析克隆结构。在最近对氟喹诺酮类药物耐药的临床分离株中，52%代表了单一的ST131亚克隆谱系，H30，它在2000年后突然扩大。该亚克隆具有独特且保守的gyrA/parc等位基因组合，支持其紧密克隆。与其他ST131亚克隆不同，H30与氟喹诺酮类耐药密切相关，是当前临床分离株中最常见的亚克隆，总耐药率为10.4%，每种耐药类型的耐药率均为11%~52%。目前大多数对氟喹诺酮类耐药的临床分离株，以及最大比例的多重耐药分离株，代表着一个高度克隆性的亚群，可能起源于单一的快速扩张和播散的ST131菌株。需要重点关注这种菌株，以控制氟喹诺酮类药物和耐多药大肠杆菌的流行。
Background. Fluoroquinolone-resistant Escherichia coli are increasingly prevalent. Their clonal origins-potentially critical for control efforts-remain undefined.Methods. Antimicrobial resistance profiles and fine clonal structure were determined for 236 diverse-source historical (1967-2009) E. coli isolates representing sequence type ST131 and 853 recent (2010-2011) consecutive E. coli isolates from 5 clinical laboratories in Seattle, Washington, and Minneapolis, Minnesota. Clonal structure was resolved based on fimH sequence (fimbrial adhesin gene: H subclone assignments), multilocus sequence typing, gyrA and parC sequence (fluoroquinolone resistance-determining loci), and pulsed-field gel electrophoresis.Results. Of the recent fluoroquinolone-resistant clinical isolates, 52% represented a single ST131 subclonal lineage, H30, which expanded abruptly after 2000. This subclone had a unique and conserved gyrA/parC allele combination, supporting its tight clonality. Unlike other ST131 subclones, H30 was significantly associated with fluoroquinolone resistance and was the most prevalent subclone among current E. coli clinical isolates, overall (10.4%) and within every resistance category (11%-52%).Conclusions. Most current fluoroquinolone-resistant E. coli clinical isolates, and the largest share of multidrug-resistant isolates, represent a highly clonal subgroup that likely originated from a single rapidly expanded and disseminated ST131 strain. Focused attention to this strain will be required to control the fluoroquinolone and multidrug-resistant E. coli epidemic.