Urinary tract infections (UTIs) are highly prevalent globally, and various antibiotics are employed for their treatment. However, the emergence of drug-resistant uropathogens towards these antibiotics causes a high rate of morbidity and mortality. This study was conducted at the Microbiology Laboratory of Grande International Hospital from November 2021 to May 2022 and aimed to assess the prevalence of UTI caused by Escherichia coli and their antibiotic susceptibility pattern with a focus on extended-spectrum beta-lactamases (ESBLs) and the prevalence of two genes (bla_CTX-M and bla_TEM) in cephalosporin-resistant E. coli. Altogether, 1050 urine samples were processed to obtain 165 isolates of E. coli. The isolates were identified by colony morphology and biochemical characteristics. Antimicrobial susceptibility tests (ASTs) were determined by the Kirby–Bauer disk diffusion method, and their ESBL enzymes were estimated by the combined disk method (CDM). Two ESBL genes (bla_CTX-M and bla_TEM) were investigated by polymerase chain reaction (PCR) in cefotaxime-resistant E. coli. Among the 1050 urine samples that were processed, 335 (31.9%) were culture-positive with 165 (49.2%) identified as E. coli. The age group ≥60 years (30.3%) had greater susceptibility to bacterial infections. AST revealed that meropenem was highly effective (95.7% susceptibility), while ampicillin showed the least sensitivity (42.4%). Among the E. coli isolates, 86 were multidrug resistant (MDR) and 10 were extensively drug resistant (XDR). Of these, 46 MDR (96%) and 2 XDR (4%) were ESBL producers. The prevalence of ESBL genes (bla_CTX-M and bla_TEM) was 49.3% and 54.8%, respectively. The overall accuracy of CDM as compared to PCR for the detection of the bla_CTX-M gene was 55.26%. The prevalence of MDR E. coli harboring the bla_CTX-M and bla_TEM genes underscores the imperative role of ESBL testing in accurately identifying both beta-lactamase producers and nonproducers.

中文翻译：

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尼泊尔中部三级医疗机构回收的头孢噻肟耐药大肠杆菌中 blaCTX-M 和 blaTEM 基因的流行率：一项描述性横断面研究

尿路感染（UTI）在全球范围内非常普遍，并且使用各种抗生素来治疗。然而，对这些抗生素产生耐药性的尿路病原体的出现导致高发病率和死亡率。这项研究于 2021 年 11 月至 2022 年 5 月在格兰德国际医院微生物学实验室进行，旨在评估大肠杆菌引起的尿路感染的患病率及其抗生素敏感性模式，重点关注超广谱 β-内酰胺酶 (ESBL) 和抗生素两种基因（bla _CTX-M和bla _TEM）在头孢菌素耐药大肠杆菌中的流行情况。总共处理了 1050 个尿液样本，获得了 165 个大肠杆菌分离株。通过菌落形态和生化特征来鉴定分离株。通过Kirby-Bauer纸片扩散法测定抗菌药物敏感性试验（AST），并通过组合纸片法（CDM）估计其ESBL酶。通过聚合酶链式反应 (PCR) 在头孢噻肟耐药大肠杆菌中研究了两种 ESBL 基因（bla _CTX-M和bla _TEM ） 。在处理的 1050 份尿液样本中，335 份（31.9%）培养呈阳性，其中 165 份（49.2%）被鉴定为大肠杆菌。≥60岁的年龄组（30.3%）更容易受到细菌感染。AST 显示美罗培南非常有效（敏感性为 95.7%），而氨苄青霉素的敏感性最低（42.4%）。在大肠杆菌分离株中，86 株具有多重耐药性 (MDR)，10 株具有广泛耐药性 (XDR)。其中，46 个 MDR (96%) 和 2 个 XDR (4%) 是 ESBL 生产者。ESBL基因（bla _CTX-M和bla _TEM）的患病率分别为49.3%和54.8%。与 PCR 相比，CDM 检测bla _CTX-M基因的总体准确率为 55.26%。携带bla _CTX-M和bla _{TEM基因的 MDR}大肠杆菌的流行强调了 ESBL 检测在准确识别 β-内酰胺酶生产者和非生产者方面的重要作用。