Molecular Epidemiological Analysis of Escherichia coli Sequence Type ST131 (O25:H4) and blaCTX-M-15 among Extended-Spectrum-β- Lactamase-Producing E. coli from the United States, 2000 to 2009
Molecular Epidemiological Analysis of Escherichia coli Sequence Type ST131 (O25:H4) and blaCTX-M-15 among Extended-Spectrum-β- Lactamase-Producing E. coli from the United States, 2000 to 2009
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DOI：
10.1128/aac.05824-11
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发表时间：
2012-05-01
影响因子：
4.9
通讯作者：
Kuskowski, Michael A.
中科院分区：
文献类型：
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作者：
Johnson, James R.;Urban, Carl;Kuskowski, Michael A.
大肠埃希菌ST131(来源于系统发育群B2)，常携带超广谱β-内酰胺酶(ESBL)基因blA(CTX-M-15)，是一种新出现的全球性传播的病原体，在美国受到的关注相对较少。因此，从15个美国中心(2000年至2009年收集)收集的351株产超广谱β-内酰胺酶(ESBL)的大肠埃希菌样本进行了基于聚合酶链式反应的系统分类和ST131和BLA(CTX-M-15)的检测。共分离到200株细菌，每组50株，分别为(I)bla(CTX-M-15)阴性的non-ST131、(Ii)bla(CTX-M-15)阳性的non-ST131、(Iii)bla(CTX-M-15)阴性的ST131或(Iv)bla(CTX-M-15)阳性的ST131。总体而言，201株(57%)分离株显示BLA(CTX-M-15)，而165株(47%)为ST131。ST131在bla(CTX-M-15)阳性菌株中占56%，而在bla(CTX-M-15)阴性菌株中占35%(P<；0.001)。在175株B2组分离株中，ST131株占94%，非ST131株按BLA(CTX-M-15)状态分布，以A组(BLA(CTX-M-15)阳性株)和D组(BLA(CTX-M-15)阴性株)为主。BLA(CTX-M-15)和ST131都发生在所有参与中心，从儿童和成人中恢复，在2003年后患病率显著增加，并与分子推断的毒力有关。与非ST131分离株相比，ST131分离株具有更高的毒力评分、独特的毒力图谱和更同质的PFGE图谱。BLA(CTX-M-15)与广泛耐药有关，ST131与氟喹诺酮类耐药相关。因此，大肠杆菌ST131和BLA(CTX-M-15)在美国ESBL阳性的大肠杆菌菌株中很常见，分布广泛，在儿童和成人中都是如此。毒力和抗菌素耐药性的增强可能促进了这些新出现的公共卫生威胁的流行病学成功。
Escherichia coli sequence type ST131 (from phylogenetic group B2), often carrying the extended-spectrum-beta-lactamase (ESBL) gene bla(CTX-M-15), is an emerging globally disseminated pathogen that has received comparatively little attention in the United States. Accordingly, a convenience sample of 351 ESBL-producing E. coli isolates from 15 U.S. centers (collected in 2000 to 2009) underwent PCR-based phylotyping and detection of ST131 and bla(CTX-M-15). A total of 200 isolates, comprising 4 groups of 50 isolates each that were (i) bla(CTX-M-15) negative non-ST131, (ii) bla(CTX-M-15) positive non-ST131, (iii) bla(CTX-M-15) negative ST131, or (iv) bla(CTX-M-15) positive ST131, also underwent virulence genotyping, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis (PFGE). Overall, 201 (57%) isolates exhibited bla(CTX-M-15), whereas 165 (47%) were ST131. ST131 accounted for 56% of bla(CTX-M-15)-positiveversus 35% of bla(CTX-M-15)-negative isolates (P < 0.001). Whereas ST131 accounted for 94% of the 175 total group B2 isolates, non-ST131 isolates were phylogenetically distributed by bla(CTX-M-15) status, with groups A (bla(CTX-M-15)-positive isolates) and D(bla(CTX-M-15)negative isolates) predominating. Both bla(CTX-M-15) and ST131 occurred at all participating centers, were recovered from children and adults, increased significantly in prevalence post-2003, and were associated with molecularly inferred virulence. Compared with non-ST131 isolates, ST131 isolates had higher virulence scores, distinctive virulence profiles, and more-homogeneous PFGE profiles. bla(CTX-M-15) was associated with extensive antimicrobial resistance and ST131 with fluoroquinolone resistance. Thus, E. coli ST131 and bla(CTX-M-15) are emergent, widely distributed, and predominant among ESBL-positive E. coli strains in the United States, among children and adults alike. Enhanced virulence and antimicrobial resistance have likely promoted the epidemiological success of these emerging public health threats.