In this study, an optical contactless laser speckle imaging technique for the early identification of bacterial colony-forming units was tested. The aim of this work is to compare the laser speckle imaging method for the early assessment of microbial activity with standard visual inspection under white light illumination. In presented research, the growth of Vibrio natriegens bacterial colonies on the solid medium was observed and analyzed. Both – visual examination under white light illumination and laser speckle correlation analysis were performed. Based on various experiments and comparisons with the theoretical Gompertz model, colony radius growth curves were obtained. It was shown that the Gompertz model can be used to describe both types of analysis. A comparison of the two methods shows that laser speckle contrast imaging, combined with signal processing, can detect colony growth earlier than standard CFU counting method under white light illumination.

中文翻译：

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激光散斑成像技术可及早发现微生物菌落形成单位

在这项研究中，测试了一种用于早期识别细菌菌落形成单位的光学非接触式激光散斑成像技术。这项工作的目的是将激光散斑成像方法与白光照射下的标准目视检查相比较，以便对微生物活性进行早期评估。在提出的研究中，纳氏弧菌的生长观察并分析固体培养基上的细菌菌落。都进行了白光照明下的目视检查和激光散斑相关性分析。基于各种实验并与理论Gompertz模型进行比较，获得了菌落半径生长曲线。结果表明，Gompertz模型可用于描述两种类型的分析。两种方法的比较表明，在斑点白光照射下，激光散斑对比度成像结合信号处理可以比标准CFU计数方法更早地检测菌落生长。