FIG. 1.

Actin tail phenotypes of rickettsiae and comparison to tails of L. monocytogenes. Dual fluorescent staining of intracellular bacteria and F-actin was conducted on Vero cells. F-actin was stained with rhodamine phalloidin (red), and intracellular bacteria were stained by indirect immunofluorescence (green). Cells were visualized by laser scanning confocal microscopy. (A) R. rickettsii showing long actin tails that are frequently comprised of multiple, twisting, distinct F-actin bundles. (B) High magnification of an R. rickettsii actin tail in panel A comprised of two F-actin bundles. (C) Truncated hook-shaped tail of R. typhi (arrow). (D) R. prowazekii with no actin tails. (E) Actin comet tails of L. monocytogenes. Bars, 5 μm.