Abstract

Group A Streptoccocus (GAS) is among the most diverse of all human pathogens, responsible for a range of clinical manifestations, from mild superficial infections such as pharyngitis to serious invasive infections such as necrotising fasciitis and sepsis. The drivers of these different disease phenotypes are not known. The GAS cholesterol-dependent cytolysin, Streptolysin O (SLO), has well established cell and tissue destructive activity. We investigated the role of SLO in determining disease outcome in vivo, by using two different clinical lineages; the recently emerged hypervirulent outbreak emm type 32.2 strains, which result in sepsis, and the emm type 1.0 strains which cause septic arthritis. Using clinically relevant in vivo mouse models of sepsis and a novel septic arthritis model, we found that the amount and activity of SLO was vital in determining the course of infection. The emm type 32.2 strain produced large quantities of highly haemolytic SLO that resulted in rapid development of sepsis. By contrast, the reduced concentration and lower haemolytic activity of emm type 1.0 SLO led to translocation of bacteria from blood to joints. Importantly, sepsis associated strains that were attenuated by deletion or inhibition of SLO, then also translocated to the joint, confirming the key role of SLO in determining infection niche. Our findings demonstrate that SLO is key to in vivo phenotype and disease outcome. Careful consideration should be given to novel therapy or vaccination strategies that target SLO. Whilst neutralising SLO activity may reduce severe invasive disease, it has the potential to promote chronic inflammatory conditions such as septic arthritis.

Details

Title
Streptolysin O concentration and activity is central to in vivo phenotype and disease outcome in Group A Streptococcus infection
Author
Clarke, Jenny 1 ; Baltazar Murielle 1 ; Alsahag Mansoor 2 ; Panagiotou Stavros 1 ; Pouget Marion 1 ; Paxton, William A 1 ; Pollakis Georgios 1 ; Everett, Dean 3 ; French, Neil 4 ; Kadioglu Aras 1 

 University of Liverpool, Department of Clinical Immunology, Microbiology and Immunology, Institute of Infection and Global Health, Liverpool, UK (GRID:grid.10025.36) (ISNI:0000 0004 1936 8470) 
 University of Liverpool, Department of Clinical Immunology, Microbiology and Immunology, Institute of Infection and Global Health, Liverpool, UK (GRID:grid.10025.36) (ISNI:0000 0004 1936 8470); University of Al Baha, Faculty of Applied Medical Sciences, Al Baha, Saudi Arabia (GRID:grid.10025.36) 
 Queen Elizabeth Central Hospital, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi (GRID:grid.415487.b) (ISNI:0000 0004 0598 3456) 
 University of Liverpool, Department of Clinical Immunology, Microbiology and Immunology, Institute of Infection and Global Health, Liverpool, UK (GRID:grid.10025.36) (ISNI:0000 0004 1936 8470); Queen Elizabeth Central Hospital, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi (GRID:grid.415487.b) (ISNI:0000 0004 0598 3456) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2576111936
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.