Phenotypic and genotypic characterization of enteroaggregative Escherichia coli isolates from pediatric population in Pakistan
Phenotypic and genotypic characterization of enteroaggregative Escherichia coli isolates from pediatric population in Pakistan
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DOI：
10.1111/apm.12577
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发表时间：
2016-11-01
期刊：
影响因子：
2.8
通讯作者：
Bokhari, Habib
中科院分区：
文献类型：
--
作者：
Khalil, Uzma;Younus, Mahwish;Bokhari, Habib
肠聚集性大肠杆菌（EAEC）是儿童腹泻的主要原因。本研究的目的是确定洪水受灾地区的EAEC儿童以及散发病例中EAEC的频率，确定多药耐药性，并使用体内致病模型评价毒力。从2010年至2011年从受洪水影响的地区以及巴基斯坦的零星病例中收集了225名腹泻儿童的粪便样本。对分离的EAEC菌株进行分型、超广谱β-内酰胺酶谱、gyrA和parC基因单核苷酸多态性检测及蜡虫G.梅隆内拉在225株大肠杆菌中，共鉴定出35株（12.5%）EAEC。大肠杆菌分离株。EAEC分离株对四环素、氨苄青霉素和头孢克洛具有高度耐药性。ESBL阳性率为34.28%。单核苷酸多态性（SNP）检测结果显示，gyrA（A（660）-T-660）和parC（C-330-T-330）的SNP阳性率分别为37.14%和68.57%。系统发育分析表明，B2亚型在所有EAEC分离株中更为普遍，其次是D、A、B1和不可分型（NT）。感染G.用EAEC对大蜡螟的杀灭感染剂量比大肠杆菌高100%。coli DH 5 α对照。EAEC在患有腹泻的巴基斯坦儿童中流行，他们对抗生素具有高度耐药性，主要属于B2群。流行病学监测EAEC和其他E.大肠杆菌致病型不仅对评估这些病原体在大肠杆菌病中的作用至关重要，而且对确定人群中的多药耐药性程度也至关重要。
Enteroaggregative Escherichia coli (EAEC) are a leading cause of diarrhea among children. The objective of this study was to define the frequency of EAEC among diarrheal children from flood-affected areas as well as sporadic cases, determine multidrug resistance, and evaluation of virulence using an in vivo model of pathogenesis. Stool samples were collected from 225 diarrheal children from 2010 to 2011 from flood-affected areas as well as from sporadic cases in Pakistan. Identified EAEC isolates were characterized by phylogrouping, antibiotic resistance patterns including the extended-spectrum beta lactamase spectrum, single nucleotide polymorphism detection in gyrA and parC, and virulence potential using wax worm, G. mellonella. A total of 35 (12.5%) confirmed EAEC isolates were identified among 225 E. coli isolates. EAEC isolates displayed high resistance to tetracycline, ampicillin, and cefaclor. A total of 34.28% were ESBL positive. Single nucleotide polymorphism detection revealed 37.14% and 68.57% isolates were positive for SNPs in gyrA (A(660)-T-660) and parC (C-330-T-330), respectively. Phylogrouping revealed that B2 phylogroup was more prevalent among all EAEC isolates tested followed by D, A, B1, and non-typeable (NT). Infection of G. mellonella with EAEC showed that killing infective dose was 100% higher than E. coli DH5 alpha control. EAEC are prevalent among Pakistani children with diarrhea, they are highly resistant to antibiotics, and predominantly fall into B2 phylogroup. Epidemiologic surveillance of EAEC and other E. coli pathotypes is critical to assess not only the role of these pathogens in diarrheal disease but also to determine the extent of multidrug resistance among the population.