Extraintestinal pathogenic Escherichia coli (ExPEC) strains are causing a great range of infections such as bacteriuria, bloodstream and urinary tract infections (1-3). Accordingly, it has been reported as the prevalent cause of bacteremia worldwide with the persistent growing rate accounting for 30% of all bacteremia (4, 5). Urinary tract infections (UTIs) has been indicated as the most frequent bacterial infectious diseases (6) under the effect of sex and age, mostly found in females of all ages (7). The involuted treatment of UTI due to the increasing prevalence of antibacterial resistance of E. coli strains of particular phylogenetic groups (8-11) has been considered Abstract Background: Escherichia coli as one of the most predominant pathogens is the major cause of urinary tract infections (UTI) worldwide. E. coli strains could be classified into distinct phylo-groups based on PCR method. Additionally, studying the antimicrobial resistance profiles of these strains is essential for finding the effective selection of treatment and evaluating the differences among resistance patterns of particular phylogenetic groups. This study aimed to determine the phylogroups of E. coli isolated from patients with UTI in Tehran, Iran. Methods: The urine samples were collected from patients suspected to UTI from four hospitals in Tehran, Iran; Mofid, Vali-Asr, Bu-Ali and Tehran Heart Center (THC) Hospitals during 2014-2016. Assessing the antimicrobial resistance profile of the identified strains was accomplished using ampicillin, ceftriaxone, cefotaxime, and ceftazidime among β-lactam group; gentamicin, and streptomycin among aminoglycosides; nalidixic acid and norfloxacin from quinolones; and chloramphenicol disks. The phylogenetic characterization of 60 E. coli isolates obtained from patients with UTI was done by triplex PCR method. Results: E. coli strains showed high resistance toward streptomycin (93.33%), ampicillin (86.6%) and nalidixic acid (73.33%) while resistance against chloramphenicol showed the lowest (10%). The prevalent groups were B2 (n=50/60, 83%), followed by D (n=6/60, 10%), B1 (n=3/60, 5%), and A (n=1, 1.6%). Conclusion: The most predominant phylogenetic group was B2 with the major frequent detected with the major drug resistant (48%) compared to other Phylogenetic groups.

中文翻译：

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从 UTI 疑似患者中分离出的大肠杆菌菌株的系统发育分析和抗菌素耐药性概况

肠外致病性大肠杆菌 (ExPEC) 菌株会引起范围广泛的感染，例如菌尿、血流和尿路感染 (1-3)。因此，据报道，它是全世界菌血症的普遍原因，其持续增长的速度占所有菌血症的 30% (4, 5)。在性别和年龄的影响下，尿路感染 (UTI) 已被认为是最常见的细菌感染性疾病 (6)，主要见于所有年龄段的女性 (7)。由于特定系统发育组 (8-11) 的大肠杆菌菌株的抗菌耐药性日益普遍，UTI 的卷曲治疗已被认为是抽象背景：大肠杆菌作为最主要的病原体之一是尿路感染的主要原因(UTI) 全球。E. 基于 PCR 方法，大肠杆菌菌株可分为不同的系统群。此外，研究这些菌株的抗菌素耐药性对于找到有效的治疗选择和评估特定系统发育组的耐药性模式之间的差异至关重要。本研究旨在确定从伊朗德黑兰的 UTI 患者中分离出的大肠杆菌的种系群。方法：收集伊朗德黑兰四家医院疑似尿路感染患者的尿样；2014-2016 年期间，Mofid、Vali-Asr、Bu-Ali 和德黑兰心脏中心 (THC) 医院。使用 β-内酰胺组中的氨苄青霉素、头孢曲松、头孢噻肟和头孢他啶对已鉴定菌株的抗菌素耐药性进行了评估；氨基糖苷类中的庆大霉素和链霉素；来自喹诺酮类的萘啶酸和诺氟沙星；和氯霉素磁盘。通过三重 PCR 方法对从 UTI 患者中获得的 60 株大肠杆菌分离株进行系统发育表征。结果：大肠杆菌菌株对链霉素（93.33%）、氨苄青霉素（86.6%）和萘啶酸（73.33%）耐药率较高，而对氯霉素耐药率最低（10%）。流行组是 B2 (n=50/60, 83%)，其次是 D (n=6/60, 10%)、B1 (n=3/60, 5%) 和 A (n=1, 1.6 %）。结论：与其他系统发育组相比，最主要的系统发育组是 B2，主要检测到主要耐药性（48%）。大肠杆菌菌株对链霉素（93.33%）、氨苄青霉素（86.6%）和萘啶酸（73.33%）的耐药性较高，而对氯霉素的耐药性最低（10%）。流行组是 B2 (n=50/60, 83%)，其次是 D (n=6/60, 10%)、B1 (n=3/60, 5%) 和 A (n=1, 1.6 %）。结论：与其他系统发育组相比，最主要的系统发育组是 B2，主要检测到主要耐药性（48%）。大肠杆菌菌株对链霉素（93.33%）、氨苄青霉素（86.6%）和萘啶酸（73.33%）的耐药性较高，而对氯霉素的耐药性最低（10%）。流行组是 B2 (n=50/60, 83%)，其次是 D (n=6/60, 10%)、B1 (n=3/60, 5%) 和 A (n=1, 1.6 %）。结论：与其他系统发育组相比，最主要的系统发育组是 B2，主要检测到主要耐药性（48%）。