Development of antibodies to PspA families 1 and 2 in children after exposure to Streptococcus pneumoniae.

Pneumococcal surface protein A (PspA) is an important virulence factor of Streptococcus pneumoniae. PspA exists as two major families, which include variable but serologically cross-reactive proteins. Previous studies with a family 1 PspA antigen suggested that children develop low concentrations of anti-PspA after pneumococcal carriage or infection.

Distribution of pneumococcal surface protein A families 1 and 2 among Streptococcus pneumoniae isolates from children in finland who had acute otitis media or were nasopharyngeal carriers.

PspA is a structurally variable surface protein important to the virulence of pneumococci. PspAs are serologically cross-reactive and exist as two major families. In this study, we determined the distribution of PspA families 1 and 2 among pneumococcal strains isolated from the middle ear fluid (MEF) of children with acute otitis media and from nasopharyngeal specimens of children with pneumococcal carriage.