Analysis of protein antigens as a potential marker for Streptococcus pneumoniae

Protein antigens of the five more common Streptococcus pneumoniae serotypes in Spain-1, 3, 4, 5 and 23 -were studied by crossed immunoelectrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Most protein antigens defined by crossed immunoelectrophoresis appeared to be common to the five serotypes studied since the degree of cross-reaction was high. Using gel electrophoresis a considerable degree of similarity in the patterns of protein bands was also observed. Thus, protein antigens would not appear to be epidemiological marker for typing pneumococci.