摘要

医院InfantildeMéxicoFedericoGómez（HIMFG）是墨西哥城的一家三级医院，经常从患有尿路感染的儿科患者的尿液样本中分离出大肠杆菌。在该研究中评估了与复杂和不复杂的尿路感染相关的178种尿中大肠杆菌（UEc）分离物的集合。对9种抗生素类别的抗性模式显示，60.7％的UEc分离株具有高度多药耐药性（MDR）特征。 UEc分离株的遗传多样性分析显示出高度的变异性，并揭示了与4个系统发育组相关的16个簇，即A，B1，B2和D组。系统发育组B2与16个簇以及毒力和适应性广泛相关。基因。 UEc分离株中的毒力和适合度基因（包括菌毛，铁载体，毒素和迁移相关基因）被分组为低频率，可变频率或高频率。有趣的是，只有papF基因可以从一些UEc分离株中扩增出来，并且pap操纵子的序列分析鉴定了插入序列（IS）元件和基因缺失。这些数据表明病原适应性和免疫系统逃避的发展，这通过UEc分离株中P菌毛相关凝集的丧失得到证实。大肠杆菌克隆O25-ST131在UEc分离株中的流行率为20.2％;这些分离株显示出高MDR谱和papGII，fimH，papGIII，iutD，sat，hlyA和motA基因的存在。总之，UEc从复杂的尿路感染（cUTI）中分离出来的特征是MDR，高度遗传多样性，并且与系统发育组B2和许多毒力和适应性基因相关。另外，在鉴定为克隆O25-ST131的一些UEc分离物中鉴定出基因缺失和IS元件。

The Hospital Infantil de México Federico Gómez (HIMFG) is a tertiary care hospital in Mexico City where Escherichia coli is frequently isolated from the urine samples of pediatric patients with urinary tract infections. A collection of 178 urinary Escherichia coli (UEc) isolates associated with complicated and uncomplicated urinary tract infections were evaluated in this study. The patterns of resistance to 9 antibiotic classes showed that 60.7% of the UEc isolates had a highly multidrug-resistant (MDR) profile. Genetic diversity analyses of the UEc isolates showed a high variability and revealed 16 clusters associated with four phylogenetic groups, namely, groups A, B1, B2, and D. Phylogenetic group B2 was widely associated with the 16 clusters as well as with virulence and fitness genes. The virulence and fitness genes in the UEc isolates, which included fimbriae-, siderophore-, toxin-, and mobility-associated genes, were grouped as occurring at a low, variable, or high frequency. Interestingly, only the papF gene could be amplified from some UEc isolates, and the sequence analysis of the pap operon identified an insertion sequence (IS) element and gene loss. These data suggested pathoadaptability and the development of immune system evasion, which was confirmed by the loss of P fimbriae-associated agglutination in the UEc isolates. E. coli clone O25-ST131 had a prevalence of 20.2% among the UEc isolates; these isolates displayed both a highly MDR profile and the presence of the papGII, fimH, papGIII, iutD, sat, hlyA, and motA genes. In conclusion, the UEc isolates from complicated urinary tract infection (cUTI) were characterized as being MDR, highly genetically diverse, and associated with phylogenetic group B2 and many virulence and fitness genes. Additionally, gene loss and IS elements were identified in some UEc isolates identified as clone O25-ST131.

https://www.ncbi.nlm.nih.gov/pubmed/30286185