Bacterial genome-wide association study of hyper-virulent pneumococcal serotype 1 identifies genetic variation associated with neurotropism

Commun Biol. 2020 Oct 8;3(1):559. doi: 10.1038/s42003-020-01290-9.

Abstract

Hyper-virulent Streptococcus pneumoniae serotype 1 strains are endemic in Sub-Saharan Africa and frequently cause lethal meningitis outbreaks. It remains unknown whether genetic variation in serotype 1 strains modulates tropism into cerebrospinal fluid to cause central nervous system (CNS) infections, particularly meningitis. Here, we address this question through a large-scale linear mixed model genome-wide association study of 909 African pneumococcal serotype 1 isolates collected from CNS and non-CNS human samples. By controlling for host age, geography, and strain population structure, we identify genome-wide statistically significant genotype-phenotype associations in surface-exposed choline-binding (P = 5.00 × 10-08) and helicase proteins (P = 1.32 × 10-06) important for invasion, immune evasion and pneumococcal tropism to CNS. The small effect sizes and negligible heritability indicated that causation of CNS infection requires multiple genetic and other factors reflecting a complex and polygenic aetiology. Our findings suggest that certain pathogen genetic variation modulate pneumococcal survival and tropism to CNS tissue, and therefore, virulence for meningitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Central Nervous System / microbiology
  • Child
  • Child, Preschool
  • Genetic Variation / genetics*
  • Genome-Wide Association Study
  • Humans
  • Infant
  • Meningitis, Pneumococcal / microbiology*
  • Phylogeny
  • Polymorphism, Single Nucleotide
  • Sequence Analysis, DNA
  • Streptococcus pneumoniae / genetics
  • Streptococcus pneumoniae / isolation & purification
  • Streptococcus pneumoniae / pathogenicity*
  • Streptococcus pneumoniae / physiology
  • Viral Tropism / genetics*