Clinical Snapshot of Group A Streptococcal Isolates from an Australian Tertiary Hospital
Phoebe K. Shaw,
Andrew J. Hayes,
Maree Langton,
Angela Berkhout,
Keith Grimwood,
Mark R. Davies,
Mark J. Walker,
Stephan Brouwer
Affiliations
Phoebe K. Shaw
Australian Infectious Diseases Research Centre, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4067, Australia
Andrew J. Hayes
Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
Maree Langton
Gold Coast Laboratory, Pathology Queensland, Gold Coast, QLD 4215, Australia
Angela Berkhout
Infection Management and Prevention Service, Queensland Specialist Immunisation Service, Children’s Health Queensland, South Brisbane, QLD 4101, Australia
Keith Grimwood
Gold Coast and Departments of Infectious Diseases and Paediatrics, Gold Coast Health, School of Medicine and Dentistry, Griffith University, Gold Coast, QLD 4215, Australia
Mark R. Davies
Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
Mark J. Walker
Australian Infectious Diseases Research Centre, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4067, Australia
Stephan Brouwer
Australian Infectious Diseases Research Centre, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4067, Australia
Streptococcus pyogenes (Group A Streptococcus, GAS) is a human-restricted pathogen that causes a wide range of diseases from pharyngitis and scarlet fever to more severe, invasive infections such as necrotising fasciitis and streptococcal toxic shock syndrome. There has been a global increase in both scarlet fever and invasive infections during the COVID-19 post-pandemic period. The aim of this study was the molecular characterisation of 17 invasive and non-invasive clinical non-emm1 GAS isolates from an Australian tertiary hospital collected between 2021 and 2022. Whole genome sequencing revealed a total of nine different GAS emm types with the most prevalent being emm22, emm12 and emm3 (each 3/17, 18%). Most isolates (14/17, 82%) carried at least one superantigen gene associated with contemporary scarlet fever outbreaks, and the carriage of these toxin genes was non-emm type specific. Several mutations within key regulatory genes were identified across the different GAS isolates, which may be linked to an increased expression of several virulence factors. This study from a single Australian centre provides a snapshot of non-emm1 GAS clinical isolates that are multiclonal and linked with distinct epidemiological markers commonly observed in high-income settings. These findings highlight the need for continual surveillance to monitor genetic markers that may drive future outbreaks.
