Mechanisms of the spread of penicillin resistance in Streptococcus pneumoniae strains causing meningitis in children in France.

The molecular epidemiology of penicillin-resistant Streptococcus pneumoniae strains causing meningitis in children was studied in France. Typing procedures included analysis of total DNA polymorphism by random amplification of polymorphic DNA, restriction fragment length polymorphism (RFLP) analysis of the ribosomal RNA gene regions, and pulsed-field gel electrophoresis. Penicillin-binding protein (PBP) genes pbp2b and pbp2x were studied by RFLP analysis and DNA sequencing in selected cases. Statistical analysis of the data by factorial analysis of correspondence established that the emergence of penicillin-resistant pneumococci in this pathology is the result of the spread of two highly resistant closely related clusters and a cluster of serotype 23 strains with an intermediate level of resistance, the spread of genes confering high resistance to penicillin between the two highly resistant clusters, and complex genetic events involving the pbp genes in a heterogeneous population of strains leading to an intermediate level of resistance.