Urban river pollution by multidrug-resistant (MDR) bacteria constitutes an important public health concern. Epidemiologically important strains of MDR Escherichia coli transmissible at the human-animal-environment interfaces are especially worrying. Quantifying and characterizing MDR E. coli at a molecular level is thus imperative for understanding its epidemiology in natural environments and its role in the spread of resistance in precise geographical areas. Cefotaxime-resistant E. coli was characterized along the watercourse of the major urban river in Quito. Our results showed high quantities of cefotaxime-resistant E. coli (2.7 × 103-5.4 × 105 CFU/100 mL). The antimicrobial resistance index (ARI) revealed the exposure of the river to antibiotic contamination, and the multiple antibiotic resistance index indicated a high risk of contamination. The blaCTX-M-15 gene was the most prevalent in our samples. Isolates also had class 1 integrons carrying aminoglycoside-modifying enzymes and folate pathway inhibitors. The isolates belonged to phylogroups A, B1 and D. Clonal complex 10 was found to be the most prevalent (ST10, ST44 and ST 167), followed by ST162, ST394 and ST46. Our study provides a warning about the high potential of the major urban river in Quito for spreading the epidemiologically important MDR E. coli.

中文翻译：

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厄瓜多尔基多的Machángara城市河流中存在大量的耐多药大肠杆菌。

耐多药（MDR）细菌污染城市河流构成了重要的公共卫生问题。在人类-动物-环境界面上可传播的MDR大肠杆菌的流行病学重要菌株尤其令人担忧。因此，在分子水平上定量和鉴定MDR大肠杆菌对于了解其在自然环境中的流行病学及其在精确地理区域中耐药性传播中的作用非常重要。耐头孢噻肟大肠埃希菌的特征是基多主要城市河流沿河道。我们的结果表明，耐头孢噻肟的大肠杆菌数量很多（2.7×103-5.4×105 CFU / 100 mL）。抗菌素耐药性指数（ARI）显示河流受到抗生素污染，多重抗生素耐药性指数表明污染的风险很高。blaCTX-M-15基因在我们的样本中最为普遍。分离物还具有携带氨基糖苷修饰酶和叶酸途径抑制剂的1类整联蛋白。该分离物属于系统群A，B1和D。发现克隆复合体10是最普遍的（ST10，ST44和ST 167），其次是ST162，ST394和ST46。我们的研究为基多主要城市河流在传播具有流行病学意义的耐多药大肠埃希氏菌方面具有巨大潜力提供了警告。