Fig. 1: Experimental trajectories in the absence of host cells (HCs) and estimation of motility parameters.
From: Statistics of pathogenic bacteria in the search of host cells
In a–c, we chose in each of them one motile bacterium, with a distinct angular speed Ω, from a population that includes motile as well as non-motile bacteria, and display its trajectory. The different panels illustrate the presence of different types of bacterial trajectories. d At short time-scales we observe that the longest axis of the bacterium oscillates, however, the center of mass of the bacterium moves along smooth paths. e Speed fluctuations: speed u— computed using two consecutive frame, i.e., n = 1—vs time in a representative trajectory. Error bars correspond to the experimental SE in the estimation of u, see details on the Supplementary Note 2. f Distribution of the speed u computed for n = 1 and 5 values. The red curve corresponds to Eq. (4). g Speed correlations A, using n = 1. The red curve corresponds to Eq. (1). h Moving direction correlations B, averaging over 1Δt and 5Δt. The red curve corresponds to Eq. (2). Note that correlations remain unchanged for n = 1 and n = 5. For further details, see Supplementary Note 1 and 2, as well as Supplementary Fig. 1.
