Virulence phenotypes of S. pneumoniae strains harboring deletion of individual ccn genes.

Survival curve of ICR outbred mice after infection with ~10⁷ CFU in a 50 μL inoculum of the following S. pneumoniae strains: (A) IU781 (D39), NRD10073 (ΔccnA), and NRD10077 (ΔccnE); (B) IU781 (D39), NRD10074 (ΔccnB), NRD10075 (ΔccnC), and NRD10076 (ΔccnD). Eight mice were infected per strain. Disease progression of animals was monitored, the time at which animals reached a moribund state was recorded, and these mice were subsequently euthanized as described in Materials and Methods. A survival curve was generated from this data and analyzed by Kaplan-Meier statistics and log rank test to determine P-values.

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