Figure 6. Nasopharyngeal infection is adversely affected by covR/S mutation.

Five week old female FVB/n mice were inoculated intranasally with either emm75 S. pyogenes, or ΔcovR/S S. pyogenes. To determine the duration of shedding, direct nasal samples were taken over a 21 day period. The wild type strain was shed over a significantly longer time period than the ΔcovR/S strain (A, 1.5×10⁸ cfu per dose, n = 20 per group, Logrank Mantel Cox p<0.05). Shedding intensity maps display the data from direct nasal samples throughout the time course from the groups infected with the wild type emm75 strain (B) and the mice infected with the ΔcovR/S strain (C). Rows indicate individual mice throughout the time course, colours indicate the numbers of S. pyogenes recovered from direct nasal samples with red indicating the highest recorded levels of carriage (≥5000 cfu) and green indicates the lowest levels of carriage (1 cfu) and blank blocks indicate no recovery of S. pyogenes. Black line indicates survival based on the first loss of carriage.