Figure 2. Persistent upper airway colonisation following neonatal co-infection.

Bacterial burden in the upper airways (nasopharynx, (A)) and lower airways (whole lung, (B)) was assessed at 20, 30 and 40 days of age in SP and SP/IAV treated mice (n = 6−9). Data are expressed as total colony-forming units in whole lung tissues that were homogenised and grown on horse-blood agar plates. *p < 0.05 compared to day 40 SP alone.