Figure 2.
Phagocytosis of S. suis serotypes 2 and 14 by murine macrophages. Results for the well-encapsulated virulent serotype 2 strain P1/7 and its previously obtained isogenic capsule-deficient mutant Δcps2F (14) are depicted for comparison only. Bacteria, 1 × 107 colony-forming units (CFU)/mL, were incubated for 60 min with J774A.1 murine macrophage-like cells, at a multiplicity of infection of 100, and gentamicin/penicillin G was used to kill any extracellular bacteria remaining after incubation. Intracellular counts were done after 3 washes and cell lysis with water. Results represent the mean count + the standard error in 4 independent experiments. Each asterisk indicates a significant difference between strains (P < 0.05) according to the Mann–Whitney rank-sum test.