Laser Speckle Image analysis for identifying the minimum lethal concentration of ampicillin in Escherichia coli...

Understanding a pathogen's sensitivity to antimicrobial drugs through Minimum Lethal Concentration (MLC) is crucial for effective treatment planning for bactericidal drugs. In this paper, we propose a novel approach using Laser Speckle Imaging (LSI) to determine the MLC of Escherichia coli (E. coli), a common pathogenic bacterial species. LSI enables the capture and analysis of the dynamic changes in speckle patterns caused by alterations in optical scattering and shape alterations of bacterial cells as a response to antibiotic treatments through a label-free approach. The observed speckle pattern changes are correlated with the gold standard method to determine the MLC, representing the lowest concentration at which E. coli is lethally affected. The results demonstrate the potential of LSI as a reliable and rapid method for determining the MLC of E. coli. This method has much potential for antimicrobial research since it provides a quick, non-destructive evaluation of bacterial responses to various bactericidal antibiotic doses without requiring labor-intensive processes like pour plate tests to calculate the MLC.