Fig. 2

Validation of the role of selected bacterial genes in the coinfection mouse model. Intranasal challenge of 8 to 10-week-old female BALB/c mice (n = 4−11 in each group), without (A; solid symbol) or with (B; open symbol) inoculation of 250 PFUs IAV for four days. Fifty microliters of S. pneumoniae Taian-S3 goi deletion mutant (2.5 × 10⁴ CFU) was used for intranasal inoculation. Two days post bacterial infection, the mice were sacrificed and the bacterial burdens of the mouse lung was calculated via plate counting. Each symbol represents the bacterial burdens value of an individual animal (*, p < 0.01, Mann–Whitney U test compare to WT). CFU colony forming unit, Goi gene of interest, Mock without pre-challenged with IAV