FIG 1.

Shedding and persistence of emm3 serotype GAS in infant CD-1 mice are inoculum dependent. (a and b) Shedding titers (CFU) of MGAS10870 from inoculated infant mice in CD-1 litters were enumerated daily over the period of days 1 to 9 postinoculation, and the median shed titers were detected throughout this period (a) and during the acute shedding phase of infection (days 1 to 3 postinoculation) (b). (c) Intranasal MGAS10870 tissue burden (left axis) and rate of persistence (right axis) in CD-1 litters were assessed at day 11 postinoculation and quantified as streptococcal CFU per milligram of homogenized nasal tissue. The medians and ranges of detected titers (box-and-whisker plot) are shown to indicate the median shedding titer and rate (a and b). The geometric mean GAS burdens (red lines) are shown to indicate the mean colonization burden and persistence rate (green line) (c). Litters are indicated by the inocula (CFU) administered, shown on the x axis. The limit of detection is indicated by the dotted line (shedding titer, 1 CFU; colonization burden, 0.1 CFU/mg). Significance was determined by a Mann-Whitney U test (**, P < 0.01).