Escherichia coli activity characterization using a laser dynamic speckle technique

TL;DR

This study demonstrates that laser dynamic speckle techniques can effectively characterize Escherichia coli activity in solid media, providing a non-invasive method to monitor bacterial activity over time.

Contribution

The paper introduces a novel application of laser dynamic speckle and temporal difference analysis for bacterial activity characterization in solid media.

Findings

Speckle activity correlates with bacterial inoculum concentration.

The technique differentiates between inoculated and control compartments.

Dynamic speckle can monitor bacterial activity over time.

Abstract

The results of applying a laser dynamic speckle technique to characterize bacterial activity are presented. The speckle activity was detected in two-compartment Petri dishes. One compartment was inoculated and the other one was left as a control blank. The speckled images were processed by the recently reported temporal difference method. Three inoculums of 0.3, 0.5, and 0.7 McFarland units of cell concentration were tested; each inoculum was tested twice for a total of six experiments. The dependences on time of the mean activity, the standard deviation of activity and other descriptors of the speckle pattern evolution were calculated for both the inoculated compartment and the blank. In conclusion the proposed dynamic speckle technique allows characterizing the activity of Escherichia coli bacteria in solid medium.