Anorue Micheal, Ejikeugwu Chika, Iroha Chidinma Stacy, David Ebuka Elijah, Nwabueze Ejike Francis, Iroha Ifeanyichukwu Romanus
Medical Laboratory Unit Alex, Ekwueme Federal University Teaching Hospital, Abakaliki, Nigeria.
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Science, Enugu State University of Science and Technology, Enugu, Nigeria.
BMC Infect Dis. 2025 Sep 26;25(1):1171. doi: 10.1186/s12879-025-11561-7.
Escherichia coli causing urinary tract infections (UTIs) remains the most common bacterial infection diagnosed among outpatients as well as hospitalized patients. This study aimed to detect the extended-spectrum beta-lactamase-producing E. coli habouring aminoglycosides and fluoroquinolone-resistant genes in UTI patients. A total of 372 clean-catch midstream urine samples of patients with UTI attending Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria (AE-FUTHA) was collected. The collected urine samples were processed using standard microbiology and molecular methods to isolate and identify E. coli. Detection of ESBL-producing E. coli was performed using the double-disk synergy test. The ESBL-producing E. coli were subjected to antimicrobial susceptibility testing following the standard Kirby-Bauer disk diffusion method. PCR-specific primers were used to screen for the ESBL, aminoglycosides and fluoroquinolone-resistant genes. Out of the 372 urine samples collected, 84 (22.58%) distinct E. coli isolates were recovered, out of which 24 (28.57%) were ESBL positive. While all the isolates were resistant to amoxicillin/clavulanic acid 24 (100%), others were highly resistant to aztreonam and sulfamethoxazole/trimethoprim 22 (91.7%), ceftriaxone 21 (87.5%), ceftazidime and cefotaxime 16 (66.7%). Resistance to a fluoroquinolone, a ciprofloxacin was observed in 15 (62.5%). Out of the 24 ESBL-positive isolates, 12 were selected based on their resistance to both aminoglycosides and fluoroquinolones antibiotics used. These ESBL-producing E. coli encoded OXA-1 3 (25%), SHV 3 (25%) and TEM 8 (66.7%). Fluoroquinolone genes, qnrA and qnrC were detected in all the isolates 12 (100%), while qnrB was detected in 10 (83.35). Aminoglycoside gene, ant (4')-la was detected in all the isolates 12 (100%), while aph (2")-ld was haboured by 10 (83.3%). Co-resistance of ESBL, fluoroquinolone and aminoglycoside (blaTEM + qnrA + qnrB + qnrC + ant (4')-la + aph (2")-lb) was observed in 8(66.7%). E. coli is one of the predominant bacteria isolated from UTI patients in Abakaliki. A high proportion have the ability to produce ESBL and predominantly encoded blaTEM with co-existence of fluoroquinolone gene, qnr and aminoglycoside, ant (4')-la.
引起尿路感染（UTIs）的大肠杆菌仍然是门诊患者以及住院患者中诊断出的最常见细菌感染。本研究旨在检测尿路感染患者中携带氨基糖苷类和氟喹诺酮耐药基因的产超广谱β-内酰胺酶大肠杆菌。收集了尼日利亚阿巴卡利基亚历克斯·埃克乌梅联邦大学教学医院（AE - FUTHA）372例尿路感染患者的清洁中段尿样本。使用标准微生物学和分子方法对收集的尿样进行处理，以分离和鉴定大肠杆菌。使用双盘协同试验检测产ESBL的大肠杆菌。按照标准的 Kirby - Bauer 纸片扩散法对产ESBL的大肠杆菌进行药敏试验。使用 PCR 特异性引物筛选ESBL、氨基糖苷类和氟喹诺酮耐药基因。在收集的372份尿样中，共分离出84株（22.58%）不同的大肠杆菌菌株，其中24株（28.57%）ESBL呈阳性。虽然所有菌株对阿莫西林/克拉维酸均耐药（24株，100%），但其他菌株对氨曲南和磺胺甲恶唑/甲氧苄啶耐药率较高（22株，91.7%），对头孢曲松耐药率为21株（87.5%），对头孢他啶和头孢噻肟耐药率为16株（66.7%）。观察到15株（62.5%）对氟喹诺酮类药物环丙沙星耐药。在24株ESBL阳性菌株中，基于它们对所使用的氨基糖苷类和氟喹诺酮类抗生素均耐药，选择了12株。这些产ESBL的大肠杆菌编码OXA - 1的有3株（25%），SHV的有3株（25%），TEM的有8株（66.7%）。在所有12株（100%）分离株中均检测到氟喹诺酮基因qnrA和qnrC，而qnrB在10株（83.35%）中被检测到。氨基糖苷类基因ant(4') - la在所有12株（100%）分离株中均被检测到，而aph(2") - ld在10株（83.3%）中存在。观察到8株（66.7%）存在ESBL、氟喹诺酮和氨基糖苷类的共同耐药（blaTEM + qnrA + qnrB + qnrC + ant(4') - la + aph(2") - lb）。大肠杆菌是阿巴卡利基从尿路感染患者中分离出的主要细菌之一。很大一部分具有产生ESBL的能力，且主要编码blaTEM，同时存在氟喹诺酮基因qnr和氨基糖苷类基因ant(4') - la。
