Contribution of serotype and genetic background to virulence of serotype 3 and serogroup 11 pneumococcal isolates.

ABSTRACT: The capsular serotype has long been associated with the virulence of Streptococcus pneumoniae. Here we present an in-depth study of phenotypic and genetic differences between serotype 3 and serogroup 11 S. pneumoniae clinical isolates from both the general and indigenous populations of Australia. Both serotypes/groups included clonally unrelated strains with differences in well-known polymorphic virulence genes, such as nanA and pspA, as demonstrated by multilocus sequence typing and Western blot analysis. Nonetheless, the serotype 3 strains were consistently and significantly more virulent in mice than the serogroup 11 strains. Despite extensive genomic analysis, noncapsular genes common to one serotype/group but not the other were not identified. Nevertheless, following the conversion of

SUBMITTER: McAllister LJ 

PROVIDER: S-EPMC3232656 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature