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Knowledge gaps regarding human immunity to Streptococcus pyogenes have impeded vaccine development. To address these gaps and evaluate vaccine candidates, we established a human challenge model of S. pyogenes pharyngitis. Here, we analyse antibody responses in serum and saliva against 19 antigens to identify characteristics distinguishing 19 participants who developed pharyngitis and 6 who did not.
Group A streptococcus (GAS) infections, such as pharyngitis and impetigo, can lead to rheumatic fever and rheumatic heart disease (RHD). Australian Aboriginal and Torres Strait Islander populations experience high rates of RHD and GAS skin infection, yet rates of GAS pharyngitis are unclear.
Among genes present in all group A streptococci (GAS), those encoding M-fibril and T-pilus proteins display the highest levels of sequence diversity, giving rise to the two primary serological typing schemes historically used to define strain. A new genotyping scheme for the pilin adhesin and backbone genes is developed and, when combined with emm typing, provides an account of the global GAS strain population.
Streptococcus dysgalactiae subspecies equisimilis and Streptococcus pyogenes share skin and throat niches with extensive genomic homology and horizontal gene transfer possibly underlying shared disease phenotypes.
This paper presents a comprehensive cardiac safety framework for early clinical development of Streptococcus pyogenes (Group A Streptococcus) vaccines, endorsed by the Strep A Vaccine Global Consortium and the Australian Strep A Vaccine Initiative. Given historical concerns about vaccine-associated acute rheumatic fever, we have established standardized echocardiography protocols integrated with clinical assessment for monitoring cardiac safety in early-phase vaccine trials.
Jonathan Carapetis AM AM MBBS FRACP FAFPHM PhD FAHMS Co-Head, Strep A Translation; Co-Founder of REACH 08 6319 1000 contact@thekids.org.au Head,
Streptococcus pyogenes (Group A Streptococcus, Strep A) is a Gram-positive bacterium and one of the most significant global bacterial pathogens, with disproportionate disease burden affecting low and middle-income countries. Despite substantial mortality and immune sequelae caused by Strep A, no licensed vaccines exist, and correlates of protection remain unestablished.
Over 5 days, 120 schoolchildren from two schools in the remote Kimberley region of Australia were screened for Strep A pharyngitis. Molecular point-of-care testing identified Strep A pharyngitis in 13/18 (72.2%) symptomatic children. The portability and feasibility of molecular point-of-care testing was highly practical for remote settings.
Controlled human infection (CHI) models can provide insights into transmission of pathogens such as Streptococcus pyogenes (Strep A). As part of the Controlled Human Infection with Penicillin for Streptococcus pyogenes (CHIPS) trial, we explored the potential for transmission among participants deliberately infected with the Strep A emm75 strain.
Group A Streptococcus (GAS) causes pharyngitis (sore throat) and impetigo (skin sores) GAS pharyngitis triggers rheumatic fever (RF) with epidemiological evidence supporting that GAS impetigo may also trigger RF in Australian Aboriginal children. Understanding the concurrent burden of these superficial GAS infections is critical to RF prevention. This pilot study aimed to trial tools for concurrent surveillance of sore throats and skins sore for contemporary studies of RF pathogenesis including development of a sore throat checklist for Aboriginal families and pharynx photography.