Within-host microevolution of Streptococcus pneumoniae is rapid and adaptive during natural colonisation.

10 Jul 2020
Respiratory conditions
  • Pneumonia
Type of resource
Peer-reviewed article
Author(s)
Chaguza C, Senghore M, Bojang E, Gladstone RA, Lo SW, Tientcheu PE, Bancroft RE, Worwui A, Foster-Nyarko E, Ceesay F, Okoi C, McGee L, Klugman KP, Breiman RF, Barer MR, Adegbola RA, Antonio M, Bentley SD, Kwambana-Adams BA

 

Genomic evolution, transmission and pathogenesis of Streptococcus pneumoniae, an opportunistic human-adapted pathogen, is driven principally by nasopharyngeal carriage. However, little is known about genomic changes during natural colonisation. Here, we use whole-genome sequencing to investigate within-host microevolution of naturally carried pneumococci in ninety-eight infants intensively sampled sequentially from birth until twelve months in a high-carriage African setting. We show that neutral evolution and nucleotide substitution rates up to forty-fold faster than observed over longer timescales in S. pneumoniae and other bacteria drives high within-host pneumococcal genetic diversity. Highly divergent co-existing strain variants emerge during colonisation episodes through real-time intra-host homologous recombination while the rest are co-transmitted or acquired independently during multiple colonisation episodes. Genic and intergenic parallel evolution occur particularly in antibiotic resistance, immune evasion and epithelial adhesion genes. Our findings suggest that within-host microevolution is rapid and adaptive during natural colonisation.

Read more at:

Within-host microevolution of Streptococcus pneumoniae is rapid and adaptive during natural colonisation | Nature Communications

https://www.nature.com/articles/s41467-020-17327-w