Streptococcus pneumoniae antibody

Background of Streptococcus pneumoniae antibody

Streptococcus pneumoniae are Gram positive diplococci , alpha hemolytic aerotolerant anaerobes. S. pneumoniae is a significant human pathogen, being recognized as a major cause of pneumonia in the late 19th century, and is currently the subject of many humoral immunity studies.
S. pneumoniae is a transient member of the normal flora, colonizing the nasopharynx of 40% of healthy adults and children with no adverse effects. There are more than 90 serotypes: serotypes 6, 14, 18, 19, and 23 are the most prevalent accounting for 60-80% of infections depending on the area of the world. Pneumococcal infection accounts for more deaths than any other vaccine preventable bacterial disease.
S. pneumoniae can express several different virulence factors which contribute to some of the clinical manifestations seen during infection.
PspA, a surface protein and virulence factor found on all isolates of S. pneumoniae, is highly immunogenic. PspAs share many cross-reactive epitopes, and immunization with a single PspA is cross-protective in mice against fatal infection with strains of the mouse virulent capsular types. Mucosal immunization with PspA can also elicit immunity to carriage.