FIG 6.

Transmission efficiency of a uvrA mutant. Litters of 4-day-old, C57BL/6 mice were split into two groups. The first group was colonized with a wild type (n = 11) or mutant (n = 14) strain of serotype 2 S. pneumoniae (D39), while the second half was left uncolonized. All mice were then returned to the cage, and uncolonized mice were surveyed daily for transmission by tapping the nares of each mouse against a blood agar plate. A colonization event was defined as detectable CFU on two subsequent days. (A) Transmission of the wild type (D39) and the ΔuvrA mutant was tracked over the course of 10 days. (B) Colonization levels of all donor mice were assessed at the end of the experiment. Statistics were performed with Mantel-Cox log-rank test for the transmission assay and Mann-Whitney U two-sample rank test for the colonization assay (*, P = 0.0348; ns, nonsignificant).