Comparative genomic analysis and in vivo modelling of Streptococcus pneumoniae ST3081 and ST618 isolates reveal key genetic and phenotypic differences contributing to clonal replacement of serotype 1 in The Gambia.



Bricio-Moreno, L, Ebruke, C, Chaguza, C ORCID: 0000-0002-2108-1757, Cornick, J, Kwambana-Adams, B, Yang, M, Mackenzie, G, Wren, BW, Everett, D, Antonio, M
et al (show 1 more authors) (2017) Comparative genomic analysis and in vivo modelling of Streptococcus pneumoniae ST3081 and ST618 isolates reveal key genetic and phenotypic differences contributing to clonal replacement of serotype 1 in The Gambia. The Journal of infectious diseases, 216 (10). 1318 - 1327.

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Abstract

Streptococcus pneumoniae serotype 1 is one of the leading causes of invasive pneumococcal disease (IPD) in West Africa, with ST618 being the dominant cause of IPD in The Gambia. Recently however, a rare example of clonal replacement was observed, where the ST3081 clone of serotype 1 replaced the predominant ST618 clone as the main cause of IPD. In this study, we seek to find the reasons for this unusual replacement event. Using whole genome sequence analysis and clinically relevant models of in vivo infection, we identify distinct genetic and phenotypic characteristics of the emerging ST3081 clone. We show that ST3081 is significantly more virulent than ST618 in models of invasive pneumonia, and is carried at higher densities than ST618 during nasopharyngeal carriage. We also observe ST-specific accessory genes and a unique ST-specific fixed mutation in the pneumococcal toxin pneumolysin which is associated with increased haemolytic activity in ST3081 and may contribute to increased virulence in this clone. Our study provides evidence that, within the same serotype 1 clonal complex, biological properties differ significantly from one clone to another in terms of virulence and host invasiveness, and that these differences may be the result of key genetic differences within the genome.

Item Type: Article
Uncontrolled Keywords: Pneumococcus, clonal replacement, infection models, pathogenesis
Depositing User: Symplectic Admin
Date Deposited: 21 Nov 2017 14:42
Last Modified: 18 Aug 2022 18:25
DOI: 10.1093/infdis/jix472
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3012628