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Streptococcus pneumoniae contains 3 rlrA pilus variants that are clonally related

Monica Moschioni1, Claudio Donati, Alessandro Muzzi

  • 1Novartis Vaccines, Siena, Italy.

The Journal of Infectious Diseases
|February 14, 2008
PubMed
Abstract

Insights

The rlrA pilus operon, found in 30.6% of Streptococcus pneumoniae isolates, is linked to specific bacterial genotypes. This finding aids in predicting its presence for developing new protein vaccines against pneumococcal infections.

Area of Science:

  • Microbiology
  • Vaccinology
  • Genetics

Background:

  • Pilus components of Streptococcus pneumoniae encoded by rlrA show protective potential in animal models.
  • Limited data exist on the prevalence and variation of the rlrA operon in disease-causing pneumococcal strains.

Purpose of the Study:

  • To investigate the distribution and antigenic variation of the rlrA operon in a global collection of Streptococcus pneumoniae isolates.
  • To determine the association of rlrA prevalence with pneumococcal serotype and genotype.

Main Methods:

  • Evaluated the prevalence of rlrA in 424 pneumococcal isolates using multilocus sequence typing.
  • Analyzed sequence variation within the rlrA operon across different isolates.
  • Correlated rlrA presence with pneumococcal serotype and genotype.

Main Results:

  • The rlrA islet was detected in 30.6% of the isolates, with 3 distinct clade types identified.
  • The presence of the pilus-encoding operon significantly correlated with Streptococcus pneumoniae genotype (P < .001), but not serotype.
  • A positive trend was observed for rlrA occurrence in antimicrobial-resistant pneumococci.

Conclusions:

  • Pneumococcal genotype can predict the incidence of the rlrA pilus operon.
  • This predictability is valuable for the development of novel protein-based vaccines against Streptococcus pneumoniae.

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