MLVA-typing on Streptococcus pneumoniae serotype 1 isolated from meningitis cases in Niger before the introduction of PCV-13 revealed a low genetic diversity

Abstract

Background: Serotype 1 was the most prevalent pneumococcal meningitis serotype encountered in Niger over the period 2003-2011 (pre-vaccination era), accounting for 45.3% of infections.

Methods: Multiple locus VNTR analysis (MLVA) was used to create a genotypic snapshot of a representative subset of the pneumococcal population of serotype 1.

Results: MLVA using 16 markers revealed a homogeneous genetic background of pneumococci serotype 1 from Niger, which clustered with few serotype 1 pneumococci from some African countries, while other African countries displayed different clonal complexes. DNA from Niger and from other African countries were different from pneumococci serotype 1 from European countries.

Conclusions: MLVA-typing revealed a low genetic diversity among pneumococci serotype 1 from meningitis cases in Niger in the pre-vaccination era.

Keywords: Genetic diversity; Multiple locus VNTR analysis; Niger; Serotype 1; Streptococcus pneumoniae.