Correlating bacterial motility and infection capacity

Abstract

Gastrointestinal infections by pathogenic bacteria require the pathogens  to locate and invade target cells.  The result is that the bacterial infection capacity (IC), among other relevant factors, depends on the collision frequency with cells. Using experiments with bacteria and human T84 colonic cells and  mathematical models, we show that small morphological differences among individual bacteria, e.g. aspect ratio, lead to  giant range of diffusion coefficients (DC) within the same bacterial population. Furthermore, the study reveals that  speed fluctuations, which are not of thermal origin,  are fundamental to understand bacterial motility and account for to up to 40\% of the DC. Finally, we indicate how the DC is directly related to the IC, and illustrate the phenomenon in experiments with T84 colonic cells and various Salmonella mutants.