This study aimed to evaluate the accuracy of disk diffusion and Etest methods, compared to that of the broth dilution reference method for identifying beta-lactam susceptibilities of Penicillin-Resistant, Ampicillin-Susceptible Enterococcus faecalis (PRASEF) isolates. Fifty-nine PRASEF and 15 Penicillin-Susceptible, Ampicillin-Susceptible E. faecalis (PSASEF) clinical nonrepetitive isolates were evaluated. The effectiveness of five beta-lactams (ampicillin, amoxicillin, imipenem, penicillin, and piperacillin) was tested. All antimicrobial susceptibility tests were performed and interpreted according to the Clinical and Laboratory Standards Institute guidelines. Interpretative discrepancies, such as essential agreement, categorical agreement, and errors, were assessed. The acceptability was ≥ 90% for both categorical agreement and essential agreement. Etest proved to be an accurate method for testing beta-lactam susceptibilities of the emerging PRASEF isolates, disk diffusion presented poor performance, particularly for imipenem and piperacillin.

中文翻译：

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耐青霉素，对氨苄西林敏感的粪肠球菌菌株的β-内酰胺敏感性测试：针对肉汤稀释的Etest和圆盘扩散方法的比较评估。

与肉汤稀释参考方法相比，本研究旨在评估纸片扩散和Etest方法的准确性，以鉴定抗青霉素，易受氨苄青霉素的粪便肠球菌（PRASEF）分离物的β-内酰胺敏感性。评价了59种PRASEF和15种对青霉素敏感的，对氨苄西林敏感的粪肠球菌（PSASEF）的临床非重复性分离株。测试了五种β-内酰胺（氨苄青霉素，阿莫西林，亚胺培南，青霉素和哌拉西林）的有效性。根据临床和实验室标准协会的指导原则进行了所有抗菌药敏感性试验并进行了解释。评估了解释性差异，例如基本一致性，分类一致性和错误。绝对同意和基本同意的可接受性均≥90％。Etest被证明是一种测试新兴PRASEF分离物的β-内酰胺敏感性的准确方法，磁盘扩散表现较差，特别是对亚胺培南和哌拉西林。