FIG. 1.

Positive impact of StkP on growth in lungs and bloodstream invasion. (A) Bacteria from the wild-type strains D39 and 23477 were used for intranasal infection of female MF1 outbred mice as described in reference 12. At 48 h, CFU were recovered from the lungs and blood as described in reference 12. inoc., inoculum. (B) CFU recovery from lungs after intranasal challenge with the wild-type strains and their stkP::aphA3 mutant derivatives. Infection was as described for panel A. CFU were recovered from lungs at 15 min (white bars), 24 h (dotted bars), and 48 h (grey bars). (C) CFU recovery from blood. The conditions of infection were as described for panel A, and CFU recovery was at 24 h (dotted bars) and 48 h (grey bars). Five mice were used at each time point, and suspensions of 10⁶ CFU in 50 μl of phosphate-buffered saline were used for infection. The results are expressed as numbers of CFU recovered per milliliter of blood (C) and per lung (B), and the standard error of the mean (SEM) is given.