Ungphakorn Wanchana, Malmberg Christer, Lagerbäck Pernilla, Cars Otto, Nielsen Elisabet I, Tängdén Thomas
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden; Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
J Microbiol Methods. 2017 Jan;132:69-75. doi: 10.1016/j.mimet.2016.11.001. Epub 2016 Nov 9.
This study aimed to evaluate the potential of a new time-lapse microscopy based method (oCelloScope) to efficiently assess the in vitro antibacterial effects of antibiotics. Two E. coli and one P. aeruginosa strain were exposed to ciprofloxacin, colistin, ertapenem and meropenem in 24-h experiments. Background corrected absorption (BCA) derived from the oCelloScope was used to detect bacterial growth. The data obtained with the oCelloScope were compared with those of the automated Bioscreen C method and standard time-kill experiments and a good agreement in results was observed during 6-24h of experiments. Viable counts obtained at 1, 4, 6 and 24h during oCelloScope and Bioscreen C experiments were well correlated with the corresponding BCA and optical density (OD) data. Initial antibacterial effects during the first 6h of experiments were difficult to detect with the automated methods due to their high detection limits (approximately 10CFU/mL for oCelloScope and 10CFU/mL for Bioscreen C), the inability to distinguish between live and dead bacteria and early morphological changes of bacteria during exposure to ciprofloxacin, ertapenem and meropenem. Regrowth was more frequently detected in time-kill experiments, possibly related to the larger working volume with an increased risk of pre-existing or emerging resistance. In comparison with Bioscreen C, the oCelloScope provided additional information on bacterial growth dynamics in the range of 10 to 10CFU/mL and morphological features. In conclusion, the oCelloScope would be suitable for detection of in vitro effects of antibiotics, especially when a large number of regimens need to be tested.
本研究旨在评估一种基于延时显微镜的新方法（oCelloScope）有效评估抗生素体外抗菌效果的潜力。在24小时实验中，将两株大肠杆菌和一株铜绿假单胞菌暴露于环丙沙星、黏菌素、厄他培南和美罗培南。利用从oCelloScope获得的背景校正吸收值（BCA）检测细菌生长。将oCelloScope获得的数据与自动Bioscreen C方法和标准时间杀菌实验的数据进行比较，在6至24小时的实验中观察到结果具有良好的一致性。在oCelloScope和Bioscreen C实验中1、4、6和24小时获得的活菌计数与相应的BCA和光密度（OD）数据高度相关。由于自动方法的检测限较高（oCelloScope约为10CFU/mL，Bioscreen C约为10CFU/mL）、无法区分活菌和死菌以及在暴露于环丙沙星、厄他培南和美罗培南期间细菌的早期形态变化，在实验的前6小时难以用自动方法检测到初始抗菌效果。在时间杀菌实验中更频繁地检测到再生长，这可能与工作体积较大以及存在预先存在或新出现的耐药性风险增加有关。与Bioscreen C相比，oCelloScope提供了关于10至10CFU/mL范围内细菌生长动力学和形态特征的额外信息。总之，oCelloScope适用于检测抗生素的体外效果，特别是当需要测试大量方案时。
