Quantification of Neisseria meningitidis Adherence to Human Epithelial Cells by Colony Counting

Abstract

To cause an infection, the human specific pathogen <i>Neisseria meningitides</i> must first colonize the nasopharynx. Upon tight interaction with the mucosal epithelium, <i>N. meningitidis</i> may cross the epithelial cellular barrier, reach the bloodstream and cause sepsis and/or meningitis. Since <i>N. meningitidis</i> niche is restricted to humans the availability of relevant animal models to study host-pathogen interactions are limiting. Therefore, most findings that involve <i>N. meningitidis</i> colonization derive from studies using cultured human cell lines. Human epithelial cells have been successfully used to examine and identify molecular effectors involved in initial adherence of the pathogen. Here, we describe a standard protocol to quantify the adherence of <i>N. meningitidis</i> to epithelial pharyngeal FaDu cells. Colony counts of cell lysates collected after infection are used to quantify adherence to the epithelial cells.