Data_Sheet_1_Phenotypic and genotypic characteristics of Escherichia coli strains isolated during a longitudinal follow-up study of chronic urinary tract infections.PDF

Worldwide, Urinary Tract Infections (UTIs) are an important health problem with many cases reported annually, women being the most affected. UTIs are relevant because they can become a recurrent condition, associated with different factors that contribute to the chronicity of the disease (cUTI). cUTI can be classified as persistent (peUTI) when the causative agent is the same each time the infection occurs or as reinfection (reUTI) when the associated microorganism is different. The purpose of this work was to characterize Escherichia coli isolates obtained in two prospective studies of patients with cUTI, to define which of them corresponded to peUTI and which to reUTI. A total of 394 isolates of E. coli were analyzed by agglutination with specific sera, antimicrobial susceptibility by diffusion disc test, and the phylogroups and presence of genes associated with virulence by PCR assays. Additionally, in some characterized strains adherence, invasiveness, and biofilm formation were analyzed by in vitro assays. The results showed that the peUTI strains belonged mainly to the classical UPEC serogroups (O25, O75, O6), were included in the B2 phylogroup, carried a great number of virulence genes, and were adherent, invasive, and biofilm-forming. Meanwhile, reUTI strains showed great diversity of serogroups, belonged mainly in the A phylogroup, and carried fewer virulence genes. Both peUTI and reUTI strains showed extensively drug-resistant (XDR) and multidrug-resistant (MDR) profiles in the antimicrobial susceptibility test. In conclusion, it appears that peUTIs are caused principally by classical UPEC strains, while reUTIs are caused by strains that appear to be a part of the common E. coli intestinal biota. Moreover, although both peUTI and reUTI strains presented different serotypes and phylogroups, their antimicrobial resistance profile (XDR and MDR) was similar, confirming the importance of regulating prophylactic treatments and seeking alternatives for the treatment and control of cUTI. Finally, it was possible to establish the features of the E. coli strains responsible for peUTI and reUTI which could be helpful to develop a fast diagnostic methodology.

全球范围内，尿路感染（UTIs）是一项重要的公共卫生问题，每年均有大量病例报告，女性受影响最为严重。尿路感染之所以重要，在于其可演变为反复发作的疾病状态，并与多种因素相关，这些因素共同促成了该疾病的慢性化（cUTI）。cUTI可被划分为持续性尿路感染（peUTI），即每次感染的原发病原体相同；或再感染（reUTI），即相关微生物种类不同。本研究旨在对慢性尿路感染患者中分离得到的大肠杆菌菌株进行特征描述，以确定其属于peUTI还是reUTI。共分析了394株大肠杆菌分离株，通过特异性血清的凝集反应、扩散圆盘法进行抗菌敏感性测试，以及PCR方法检测其系统发育群和与致病性相关的基因。此外，对部分特征菌株进行了体外实验，分析其粘附性、侵入性和生物膜形成能力。结果显示，peUTI菌株主要属于经典的UPEC血清群（O25、O75、O6），归属于B2系统发育群，携带大量致病基因，且具有粘附、侵入和形成生物膜的能力。与此同时，reUTI菌株在血清群上表现出高度多样性，主要分布于A系统发育群，携带的致病基因较少。peUTI和reUTI菌株在抗菌敏感性测试中均显示出广泛的耐药性（XDR）和多药耐药性（MDR）。综上所述，peUTI主要由经典的UPEC菌株引起，而reUTI则是由那些似乎构成常见大肠杆菌肠道共生生物群的部分菌株引起。此外，尽管peUTI和reUTI菌株在血清型和系统发育群上存在差异，但其抗菌耐药性特征（XDR和MDR）相似，这进一步证实了调节预防治疗和寻求慢性尿路感染治疗与控制的替代方案的重要性。最后，本研究成功确立了导致peUTI和reUTI的大肠杆菌菌株的特征，这有助于开发快速诊断方法。