FIG 2 .
NESp adherence and invasion of human epithelial cells. Detroit 562 pharyngeal (A and B) or A549 pulmonary (C and D) epithelial cells were incubated with 107 pneumococci. Adhered or intracellular bacteria were enumerated by plating on BA. A deletion of aliC and aliD in MNZ41 significantly increased adherence to both cell lines (A and C) but did not affect invasion into epithelial cells (B and D). Values are means plus standard errors of the means (error bars) from three independent studies performed in triplicate. Values that are significantly different are indicated by asterisks as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001.