Increased Virulence of an Encapsulated Streptococcus pneumoniae Upon Expression of Pneumococcal Surface Protein K

Current Streptococcus pneumoniae vaccines selectively target capsular polysaccharide of specific serotypes, leading to an increase in nonencapsulated S. pneumoniae (NESp). Cocolonization by encapsulated pneumococci and NESp increases the opportunity for intraspecies genetic exchange. Acquisition of NESp genes by encapsulated pneumococci could alter virulence and help vaccine-targeted serotypes persist in the host.Adhesion and invasion assays...