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Understanding immunity in humans to Group A Streptococcus (Strep A) is critical for the development of successful vaccines to prevent the morbidity and mortality attributed to Strep A infections. Despite decades of effort, no licensed vaccine against Strep A exists and immune correlates of protection are lacking; a major impediment to vaccine development.
Impetigo is a highly contagious bacterial infection of the superficial layer of skin. Impetigo is caused by group A Streptococcus (Strep A) and Staphylococcus aureus, alone or in combination, with the former predominating in many tropical climates. Strep A impetigo occurs mainly in early childhood, and the burden varies worldwide. It is an acute, self-limited disease, but many children experience frequent recurrences that make it a chronic illness in some endemic settings.
Pharyngitis, more commonly known as sore throat, is caused by viral and/or bacterial infections. Group A Streptococcus (Strep A) is the most common bacterial cause of pharyngitis. Strep A pharyngitis is an acute, self-limiting disease but if undertreated can lead to suppurative complications, nonsuppurative poststreptococcal immune-mediated diseases, and toxigenic presentations.
Described antimicrobial resistance mechanisms enable bacteria to avoid the direct effects of antibiotics and can be monitored by in vitro susceptibility testing and genetic methods. Here we describe a mechanism of sulfamethoxazole resistance that requires a host metabolite for activity.
Acute poststreptococcal glomerulonephritis (APSGN) is an immune complex-induced glomerulonephritis that develops as a sequela of streptococcal infections. This article provides guidelines for the surveillance of APSGN due to group A Streptococcus (Strep A). The primary objectives of APSGN surveillance are to monitor trends in age- and sex-specific incidence, describe the demographic and clinical characteristics of patients with APSGN, document accompanying risk factors, then monitor trends in frequency of complications, illness duration, hospitalization rates, and mortality.
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.
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.
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.
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.
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.