Department of Basic Medical Sciences, Faculty of Medicine, The Hashemite University, Zarqa, Jordan.
Department of Pediatrics and Neonatology, Faculty of Medicine, The Hashemite University, Zarqa, Jordan.
Ann Clin Microbiol Antimicrob. 2022 May 22;21(1):20. doi: 10.1186/s12941-022-00508-4.
Detection of Extended-Spectrum Beta-Lactamases (ESBLs) depends on screening for resistance to certain cephalosporins, confirmation with selective ESBL inhibitors, and ESBL genes detection. New tests are required for accurate ESBL detection.
To test the ability of cefixime (CFM) and cefixime-amoxicillin/clavulanate (CFM-AMC) as a screening and confirmatory test for ESBL identification.
246 clinical isolates of Escherichia coli were tested by an ESBL screening test, a double-disk synergy test (DDST), a disk replacement test, the Vitek 2 ESBL test, and an ESBL genes test by PCR. CFM ESBL Screening was performed by disk diffusion, while CFM-AMC confirmation was performed by DDST and a disk replacement test.
246 E. coli clinical isolates from two referral hospitals were collected over 2 years. The mean age ± standard deviation of patients was 43.8 ± 27.7 years and 76.8% were females. Resistance rates to penicillins, first, second, and third generation cephalosporins, and monobactams were very high at 97%, 84%, 100% and 97%, respectively. ESBL screening was positive in 81.3% of isolates, DDST was positive in 74.8%, disk replacement was positive in 79%, Vitek 2 ESBL test was positive in 67.3%, and ESBL genes were detected in 85.8% of isolates (CTX-M 75%, TEM 42.5%, SHV 4.6%). Compared to genotyping, screening with CFM achieved 87.7% sensitivity and 64.7% specificity. CFM-AMC DDST achieved 75.8% sensitivity and 75.4% specificity, and CFM-AMC disk replacement had 73% sensitivity and 70% specificity.
High prevalence of ESBLs was noted among E. coli isolates, dominated by CTX-M genotype. ESBL screening and confirmation using CFM and CFM-AMC is a new and accurate method for ESBLs detection.
检测超广谱β-内酰胺酶（ESBLs）依赖于对某些头孢菌素的耐药性筛选、用选择性 ESBL 抑制剂进行确认，以及 ESBL 基因检测。需要新的测试来准确检测 ESBL。
测试头孢克肟（CFM）和头孢克肟-阿莫西林/克拉维酸（CFM-AMC）作为 ESBL 鉴定的筛选和确认试验的能力。
对 246 株大肠埃希菌临床分离株进行 ESBL 筛选试验、双碟协同试验（DDST）、碟片替换试验、Vitek 2 ESBL 试验和 PCR 检测 ESBL 基因。CFM ESBL 筛选通过纸片扩散法进行，而 CFM-AMC 确认通过 DDST 和碟片替换试验进行。
在两年多的时间里，从两家转诊医院收集了 246 株大肠埃希菌临床分离株。患者的平均年龄±标准差为 43.8±27.7 岁，女性占 76.8%。青霉素、第一代、第二代和第三代头孢菌素以及单酰胺类抗生素的耐药率非常高，分别为 97%、84%、100%和 97%。81.3%的分离株 ESBL 筛选阳性，74.8%的 DDST 阳性，79%的碟片替换阳性，67.3%的 Vitek 2 ESBL 试验阳性，85.8%的分离株检测到 ESBL 基因（CTX-M 75%，TEM 42.5%，SHV 4.6%）。与基因分型相比，CFM 筛查的敏感性为 87.7%，特异性为 64.7%。CFM-AMC DDST 的敏感性为 75.8%，特异性为 75.4%，CFM-AMC 碟片替换的敏感性为 73%，特异性为 70%。
大肠埃希菌分离株中 ESBLs 的流行率很高，以 CTX-M 基因型为主。使用 CFM 和 CFM-AMC 进行 ESBL 筛选和确认是一种新的、准确的 ESBL 检测方法。
