PCR fingerprinting analysis for differentiation of Streptococcus pneumoniae reinfection versus relapse.

Polymerase chain reaction fingerprint profiles of isolates obtained during an episode of pneumococcal pneumonia with bacteremia differed significantly from profiles of isolates obtained from the same patient during a subsequent episode of pneumococcal meningitis with bacteremia. Polymerase chain reaction fingerprinting provides a means of differentiating new infection from relapse, and may be a simple molecular tool for comparison of Streptococcus pneumoniae isolates.