Extraintestinal pathogenic E. coli (ExPEC) is the most frequent etiological agent of urinary tract infections (UTIs). Particular evolutionary successful lineages are associated with severe UTIs and higher incidences of multidrug resistance. Most of the resistance genes are acquired by horizontal transfer of plasmids and other mobile genetic elements (MGEs), and this process has been associated with the successful dissemination of particular lineages. Here, we identified the presence of MGEs and their role in virulence and resistance profiles of isolates obtained from the urine of hospitalized patients in Brazil. Isolates belonging to the successful evolutionary lineages of sequence type (ST) 131, ST405, and ST648 were found to be multidrug-resistant, while those belonging to ST69 and ST73 were often not. Among the ST131, ST405, and ST648 isolates with a resistant phenotype, a high number of mainly IncFII plasmids was identified. The plasmids contained resistance cassettes, and these were also found within phage-related sequences and the chromosome of the isolates. The resistance cassettes were found to harbor several resistance genes, including bla_CTX-M-15. In addition, in ST131 isolates, diverse pathogenicity islands similar to those found in highly virulent ST73 isolates were detected. Also, a new genomic island associated with several virulence genes was identified in ST69 and ST131 isolates. In addition, several other MGEs present in the ST131 reference strain EC958 were identified in our isolates, most of them exclusively in ST131 isolates. In contrast, genomic islands present in this reference strain were only partially present or completely absent in our ST131 isolates. Of all isolates studied, ST73 and ST131 isolates had the most similar virulence profile. Overall, no clear association was found between the presence of specific MGEs and virulence profiles. Furthermore, the interplay between virulence and resistance by acquiring MGEs seemed to be lineage dependent. Although the acquisition of IncF plasmids, specific PAIs, GIs, and other MGEs seemed to be involved in the success of some lineages, it cannot explain the success of different lineages, also indicating other (host) factors are involved in this process. Nevertheless, the detection, identification, and surveillance of lineage-specific MGEs may be useful to monitor (new) emerging clones.

肠外致病性大肠杆菌（ExPEC）是最常见的尿路感染（UTI）病因。特定的进化成功谱系与严重的UTI和更高的多药耐药性发生率相关。大多数抗性基因是通过质粒和其他可移动遗传元件（MGE）的水平转移获得的，该过程与成功传播特定谱系有关。在这里，我们确定了MGE的存在及其在巴西住院患者尿液中分离株的毒力和耐药性谱中的作用。发现属于成功的序列类型（ST）131，ST405和ST648进化谱系的分离株具有多重耐药性，而属于ST69和ST73的分离株通常不具有耐药性。在具有抗性表型的ST131，ST405和ST648菌株中，鉴定到大量主要是IncFII质粒。质粒包含抗性盒，并且它们也存在于噬菌体相关序列和分离株的染色体内。发现抗性盒包含几个抗性基因，包括bla _CTX-M-15。此外，在ST131分离物中，发现了与高毒力ST73分离物中相似的多种致病岛。此外，在ST69和ST131分离物中鉴定出了与几个毒力基因相关的新基因岛。此外，在我们的分离株中还鉴定出了ST131参考菌株EC958中存在的其他MGE，其中大多数仅在ST131分离株中存在。相反，在我们的ST131分离物中，该参考菌株中存在的基因组岛仅部分存在或完全不存在。在研究的所有分离株中，ST73和ST131分离株的毒力谱最相似。总体而言，在特定MGE的存在与毒力特征之间没有明确的关联。此外，通过获得MGE引起的毒力和抗性之间的相互作用似乎与血统有关。尽管获得IncF质粒，特定的PAI，GI和其他MGE似乎与某些谱系的成功有关，但它不能解释不同谱系的成功，也表明其他（宿主）因素也参与了这一过程。但是，检测，鉴定和监视谱系特异性MGE可能对监视（新）新兴克隆有用。