Panagiotou, S 
ORCID: 0000-0001-9972-5068, Chaguza, C ORCID: 0000-0002-2108-1757, Yahya, R, Audshasai, T, Baltazar, M ORCID: 0000-0002-1972-2308, Ressel, L ORCID: 0000-0002-6614-1223, Khandaker, S, Alsahag, M, Mitchell, TJ, Prudhomme, M et al (show 2 more authors)
(2020)
Hypervirulent pneumococcal serotype 1 harbours two pneumolysin variants with differential haemolytic activity
Scientific Reports, 10 (1).
17313-.
ISSN 2045-2322, 2045-2322
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Text
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Abstract
Streptococcus pneumoniae is a devastating global pathogen. Prevalent in sub-Saharan Africa, pneumococcal serotype 1 is atypical in that it is rarely found as a nasopharyngeal coloniser, yet is described as one of the most common causes of invasive pneumococcal disease. Clonal sequence type (ST)-306 and ST615 are representative of the two major serotype 1 lineages A and C, respectively. Here we investigated the virulence properties and haemolytic activities of these 2 clonal types using in vivo mouse models and in vitro assays. A lethal dose of ST615 administered intranasally to mice led to the rapid onset of disease symptoms and resulted in 90% mortality. In contrast, mice exposed to the same infection dose of ST306 or a pneumolysin (Ply)-deficient ST615 failed to develop any disease symptoms. Interestingly, the 2 strains did not differ in their ability to bind the immune complement or to undergo neutrophil-mediated phagocytosis. Upon comparative genomic analysis, we found higher within-ST sequence diversity in ST615 compared with ST306 and determined that ZmpA, ZmpD proteins, and IgA protease, were uniquely found in ST615. Using cell fractionation and cell contact-dependent assay, we made the unexpected finding that ST615 harbours the expression of two haemolytic variants of Ply: a cell-wall restricted fully haemolytic Ply, and a cytosolic pool of Ply void of any detectable haemolytic activity. This is the first time such a phenomenon has been described. We discuss the biological significance of our observation in relation to the aptitude of the pneumococcus for sustaining its human reservoir.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Animals, Humans, Mice, Streptococcus pneumoniae, Hemolysis, Bacterial Proteins, Streptolysins, Virulence, Female, Serogroup |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 28 Oct 2020 10:03 |
| Last Modified: | 24 Jan 2026 02:43 |
| DOI: | 10.1038/s41598-020-73454-w |
| Open Access URL: | https://doi.org/10.1038/s41598-020-73454-w |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3105287 |
| Disclaimer: | The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate. |
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