Population structure, virulence potential and antibiotic susceptibility of uropathogenic Escherichia coli from Northwest England
Population structure, virulence potential and antibiotic susceptibility of uropathogenic Escherichia coli from Northwest England
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DOI：
10.1093/jac/dkr451
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发表时间：
2012-02-01
影响因子：
5.2
通讯作者：
Upton, Mathew
中科院分区：
文献类型：
--
作者：
Gibreel, Tarek M.;Dodgson, Andrew R.;Upton, Mathew
目的：多位点序列分型（MLST）已被用于表征多种病原体，包括尿路致病性大肠杆菌（UPEC）。人们对O25b: H4-ST131谱系在UPEC疾病中的作用非常感兴趣，因为这些分离株通常具有高毒力并表现出多药耐药性。为了揭示序列型（ST） 131的更广泛影响，我们研究了它对非根据毒力或抗生素耐药性选择的UPEC分离株的总体种群结构的贡献。方法：对2007年6月和2009年6月在英国西北地区临床微生物实验室检测的社区和医院尿液中分离到的300株UPEC分离株进行分析。通过易感谱、MLST和毒力基因PCR对其进行鉴定。采用PFGE对关键克隆的分离株进行检测。结果：最常见的是ST73(16.6%)，其次是ST131（13.3%）、ST69（9%）、ST95（6.3%）、ST10（4.3%）和ST127（3.6%）。ST131分离株更有可能表现出高水平的抗生素耐药性（35%为CTX-M-15 PCR阳性），ST127分离株最容易感染，但携带的毒力基因数量最多。只有在检测ctx - m -15- o25b阳性菌株时，才观察到ST131分离株的高毒力。PFGE表明ST131正在进行局部进化。结论：ST131分离株在更广泛的UPEC人群中已经建立。这种克隆仍在进化，我们进一步支持有关它对健康构成真正威胁的建议。我们认为ST127是最近出现的一种与社区相关的毒性克隆，值得进一步研究。
Objectives: Multilocus sequence typing (MLST) has been used to characterize diverse pathogens, including uropathogenic Escherichia coli (UPEC). There has been significant interest in the contribution of the O25b: H4-ST131 lineage to UPEC disease, as these isolates are often highly virulent and exhibit multidrug resistance. To reveal the wider impact of sequence type (ST) 131, we have examined its contribution to the overall population structure of UPEC isolates that were not selected on the basis of virulence or antibiotic resistance.Methods: Three hundred UPEC isolates were recovered from community and hospital urine samples examined by clinical microbiology laboratories in the Northwest region of England in June 2007 and June 2009. They were characterized by susceptibility profiling, MLST and virulence gene PCR. PFGE was used to examine isolates from key clones.Results: The most common lineage was ST73 (16.6%) followed by ST131 (13.3%), ST69 (9%), ST95 (6.3%), ST10 (4.3%) and ST127 (3.6%). ST131 isolates were significantly more likely to exhibit high levels of antibiotic resistance (35% being CTX-M-15 PCR positive) and those of ST127 were the most widely susceptible but carried the highest number of virulence genes. Only when the CTX-M-15-O25b-positive strains were examined was a high level of virulence observed for ST131 isolates. PFGE indicated ongoing local evolution in ST131.Conclusions: ST131 isolates are well established in the wider UPEC population. This clone is still evolving and we further support suggestions that it represents a real threat to health. We suggest that ST127 is a recently emerged, community-associated, virulent clone that warrants further study.