CCNE1 and Sepsis: To determine the contribution of the Ccn sRNAs to S. pneumoniae virulence, we initially made single deletions of ccnA, ccnB, ccnC, ccnD, or ccnE and a quintuple deletion of all five ccn genes in the archetypal serotype 2 S. pneumoniae strain D39, which causes rapid killing of mice by sepsis [20].