Quantification of the host pathogen interactions by image analysis

Ariane Kaeppeli

Semester Project

Section of Life Sciences and Technologies, EPFL

July 2014

Abstract

The aim of this project was to develop a semi-automatic image analysis tool in order to quantify the interaction between a bacterium and a cell. This could be useful to show the heterogeneity of bacteria, as it would allow a quantitative comparison between different types of bacteria. It could also help to understand why some bacteria replicate very fast compared to others and to determine the impact of potential drugs on bacteria. The method was developed as an ImageJ plugin and it is a pooling and an adaptation of already existing methods such as Hough spaces, oriented gradient, dynamic programming and backtracking. The cell segmentation and tracking is performed on phase contrast images and allows manual interventions for corrections. The bacteria segmentation is done on fluorescence images with a threshold. Finally, measurements such as cell and bacteria surfaces can be performed.