Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli clinical isolates from northern Colombia, South America.
Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli clinical isolates from northern Colombia, South America.
复制标题
肠毒素大肠杆菌临床分离株的表型和基因型表征来自北美北部。
DOI：
10.1155/2014/236260
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发表时间：
2014
影响因子：
--
通讯作者：
Gómez-Duarte OG
中科院分区：
文献类型：
--
作者：
Guerra JA;Romero-Herazo YC;Arzuza O;Gómez-Duarte OG
产肠毒素大肠杆菌（ETEC）是低收入和中等收入国家（包括哥伦比亚、南美洲）儿童腹泻的主要原因。为了了解该地区ETEC菌株的多样性，对从哥伦比亚北方儿童中获得的临床分离株进行了多位点测序分型、血清分型、经典和非经典毒力基因以及抗生素敏感性评价。在评价的40株ETEC临床分离株中，21株（52.5%）LT基因阳性，13株（32.5%）ST基因阳性，6株（15%）ST和LT均阳性。最常见的定植表面抗原（CS）分别为21株（50%）和13株（32.5%）。eatA、irp 2和fyuA是超过60%的分离株中最常见的非经典毒力基因。氨苄青霉素耐药（80%的菌株）是ETEC菌株中最常见的表型，其次是甲氧苄啶-磺胺甲恶唑耐药（52.5%）。基于多位点测序分型（MLST），我们发现在哥伦比亚流行的ETEC临床分离株有6个克隆组。来自哥伦比亚北方儿童的ETEC临床分离株具有高度多样性，但社区中传播的一些分离株属于明确定义的克隆群，这些克隆群具有一组独特的毒力因子、血清型和MLST序列类型。
Enterotoxigenic Escherichia coli (ETEC) are major causes of childhood diarrhea in low and middle income countries including Colombia, South America. To understand the diversity of ETEC strains in the region, clinical isolates obtained from northern Colombia children were evaluated for multiple locus sequencing typing, serotyping, classical and nonclassical virulence genes, and antibiotic susceptibility. Among 40 ETEC clinical isolates evaluated, 21 (52.5%) were positive for LT gene, 13 (32.5%) for ST gene, and 6 (15%) for both ST and LT. The most prevalent colonization surface antigens (CS) were CS21 and CFA/I identified in 21 (50%) and 13 (32.5%) isolates, respectively. The eatA, irp2, and fyuA were the most common nonclassical virulence genes present in more than 60% of the isolates. Ampicillin resistance (80% of the strains) was the most frequent phenotype among ETEC strains followed by trimethoprim-sulfamethoxazole resistance (52.5%). Based on multiple locus sequencing typing (MLST), we recognize that 6 clonal groups of ETEC clinical isolates circulate in Colombia. ETEC clinical isolates from children in northern Colombia are highly diverse, yet some isolates circulating in the community belong to well-defined clonal groups that share a unique set of virulence factors, serotypes, and MLST sequence types.