Minimal inhibitory concentration of antimicrobials, determined by the broth microdilution method, requires visual assessment or absorbance measurement using a spectrophotometer. Both procedures are usually performed manually, requiring the presence of an operator to assess the plates at specific time point. In order to increase the throughput of antimicrobial susceptibility testing, and concurrently convert into an automatic assay, the Biolog OmniLog® system was validated for a new, label-free application using standard 96-well microplates. OmniLog was evaluated for its signal strength to ensure that the signal intensity, detected and measured by the system's camera, was satisfactory. Variability due to the plate location inside the OmniLog incubator, as well as variation between wells, was investigated. Then the system was validated by determining the minimal inhibitory concentration of ciprofloxacin, piperacillin and linezolid against a selected Gram-negative and Gram-positive strains. No significant difference was observed in relation to position of the plates within the system. Plate edge effects were noticeable, thus the edge wells were not included in further experiments. Minimal inhibitory concentration results were comparable to those obtained by conventional protocol as well as to values defined by the Clinical Laboratory Standards Institute or published in the literature.

中文翻译：

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用于抗菌活性测定的 Biolog OmniLog ® 系统的评估和验证

通过肉汤微量稀释法确定的抗菌剂的最小抑制浓度需要使用分光光度计进行目视评估或吸光度测量。这两个过程通常都是手动执行的，需要操作员在场以在特定时间点评估板。为了提高抗菌药敏感性测试的通量，同时转换为自动检测，Biolog OmniLog® 系统使用标准 96 孔微孔板进行了新的无标记应用验证。对 OmniLog 的信号强度进行了评估，以确保系统摄像头检测和测量的信号强度令人满意。研究了由于 OmniLog 培养箱内的板位置以及孔之间的差异而导致的差异。然后通过确定环丙沙星、哌拉西林和利奈唑胺对选定的革兰氏阴性和革兰氏阳性菌株的最小抑制浓度来验证该系统。在系统内板的位置方面没有观察到显着差异。板边缘效应很明显，因此边缘孔不包括在进一步的实验中。最小抑制浓度结果与通过常规方案获得的结果以及临床实验室标准协会定义的或在文献中公布的值相当。板边缘效应很明显，因此边缘孔不包括在进一步的实验中。最小抑制浓度结果与通过常规方案获得的结果以及临床实验室标准协会定义的或在文献中公布的值相当。板边缘效应很明显，因此边缘孔不包括在进一步的实验中。最小抑制浓度结果与通过常规方案获得的结果以及临床实验室标准协会定义的或在文献中公布的值相当。