Department of Microbiology, Institute of Medical Sciences & SUM Hospital, Bhubaneswar, India.
Centre of Biotechnology, Siksha 'O' Anusandhan University, Bhubaneswar, India.
Indian J Med Res. 2017 Jul;146(Supplement):S23-S29. doi: 10.4103/ijmr.IJMR_575_16.
BACKGROUND & OBJECTIVES: The prevalence of multidrug-resistant (MDR) Escherichia coli isolates producing β-lactamase enzyme is a growing problem across the globe. Strain typing is an epidemiologically important tool not only for detecting the cross transmission of nosocomial pathogens but also for determining the source of infection. The present study was conducted to understand the clonal relationship among various β-lactamase-producing MDR E. coli isolates using enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR).
A total of 41 MDR E. coli isolates were randomly collected from various clinical samples and processed. Isolated organisms were tested for antibiotics resistance pattern. Phenotypic detection of metallo β-lactamases (MBL) was carried out by the imipenem-ethylenediaminetetraacetic acid disc diffusion/double-disc synergy test. AmpC enzyme production was tested by a modified three-dimensional extract test.
Almost all isolates were found sensitive to colistin. A high percentage of drug resistance was observed in these isolates against ceftazidime (100%), cefotaxime (100%), cefepime (100%), ofloxacin (97.56%), amoxicillin/clavulanic acid (97.56%) and norfloxacin (85.36%). Of the 41 isolates, ESBL producers were found to be predominant, i.e., 22 (53.65%), followed by AmpC (6, 14.63%) and MBL (5, 12.19%).
INTERPRETATION & CONCLUSIONS: At 60 per cent similarity cut-off value, the dendrogram analysis showed that there were a total of 14 unique clusters of ERIC (CL-1 - CL-14) within the 41 E. coli isolates, which revealed the genetic diversity existing between them.
全球范围内，产β-内酰胺酶的多药耐药（MDR）大肠杆菌分离株的流行率是一个日益严重的问题。菌株分型不仅是检测医院病原体交叉传播的重要流行病学工具，也是确定感染源的重要手段。本研究旨在使用肠杆菌重复基因间一致性（ERIC）聚合酶链反应（PCR）了解各种产β-内酰胺酶的 MDR 大肠杆菌分离株之间的克隆关系。
从各种临床样本中随机收集了 41 株 MDR 大肠杆菌分离株并进行处理。分离出的细菌进行抗生素耐药模式检测。采用亚胺培南-乙二胺四乙酸纸片扩散/双纸片协同试验进行金属β-内酰胺酶（MBL）的表型检测。采用改良三维提取试验检测 AmpC 酶的产生。
几乎所有分离株对黏菌素均敏感。这些分离株对头孢他啶（100%）、头孢噻肟（100%）、头孢吡肟（100%）、氧氟沙星（97.56%）、阿莫西林/克拉维酸（97.56%）和诺氟沙星（85.36%）的耐药率较高。在 41 株分离株中，发现 ESBL 产生菌为主，即 22 株（53.65%），其次是 AmpC（6 株，14.63%）和 MBL（5 株，12.19%）。
在 60%相似度截断值下，ERIC 聚类分析显示 41 株大肠杆菌分离株共有 14 个独特的 ERIC 聚类（CL-1 - CL-14），这表明它们之间存在遗传多样性。
