Genome evolution to penicillin resistance in serotype 3 streptococcus pneumoniae by capsular switching

Abstract

Streptococcus pneumoniae isolates of serotype 3 were collected from cases of invasive pneumococcal disease (n 124) throughout Japan between April 2010 and March 2013. A penicillin-resistant S. pneumoniae (PRSP) isolate from an adult patient, strain KK0981 of serotype 3, was identified among these strains. Whole-genome analysis characterized this PRSP as a recombinant strain derived from PRSP of serotype 23F with the cps locus (20.3 kb) replaced by that of a penicillin-susceptible strain of serotype 3.