A refined model of how Yersinia pestis produces a transmissible infection in its flea vector
Fig 9
RpiA activity is needed for the production of a thick Y. pestis biofilm that blocks the flea proventriculus.
(A) the percentage of fleas showing no masses (white), a brownish mass anchored within the proventriculus (red), or only a free-floating mass within the midgut (black) [see Fig 1], (B) the percentage of fleas containing one (grey), two (black) or more than 2 (red) proventricular casts in the midgut (regardless of the presence of a mass associated with the proventriculus), and (C) proventriculi containing no (white), very few (grey), few (black) or many (red) bacteria were determined at 2, 6 and 13 days post-infection, before (b) and immediately after (a) feeding. The stacked data from 4 independent experiments (the ΔrpiA ΔrpiA2 mutant and WT, D13, after feeding) and 5 independent experiments (WT and ΔrpiA mutant) using >15 to 20 fleas are presented (see S7 Fig). *, p <0.05 using 2-way analysis of variance with Tukey's multiple comparisons test.