Fig. 5.

Adhesion of Y. pestis chaperone/usher mutants to tissue culture cells. Y. pestis strains were added to HEp-2 (a–c), THP-1 (d–f) and RAW264.7 (g–i) cells at an m.o.i. of about 10. Cells were cultured at pH 7 28 °C (a, d, g), pH 7 37 °C (b, e, h) or pH 6 37 °C (c, f, i). THP-1 and RAW264.7 cells were blocked for phagocytosis by addition of 5 μg cytochalasin-D ml⁻¹. Results are means±sd of duplicates of three experiments on different days. *P≤0.0003.