Development of a flow cytometry based assay to determine the invasion of enteropathogenic Yersiniae into C2BBe1 cells

A rapid method was developed to determine the invasion frequency of enteropathogenic Yersinia into intestinal C2BBe1 cells by means of flow cytometry. Bacteria are labelled with a thiol-cleavable amine-reactive biotin and subsequently incubated with the fluorochrome-labelled biotin-ligand neutravidin. After infection of the intestinal cells with the labelled bacteria, the neutravidin-coupled fluorochrome is detached by breaking up the linker through reduction of the disulphide. Despite reduced adhesion and invasion frequencies of the labelled bacteria into C2BBe1 cells this procedure offers the basis for the development of a fast single-step staining protocol for the recovery of invading bacteria in in a host-pathogen system for further transcriptome or proteome analysis.