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Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae
Published on: February 24, 2023
Comparative M-protein analysis of Streptococcus pyogenes from pharyngitis and skin infections in New Zealand:
Deborah A Williamson1,2, Pierre R Smeesters3, Andrew C Steer3
1Institute of Environmental Science and Research, Wellington, New Zealand. deborah.williamson@unimelb.edu.au.
Background:
Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are responsible for a significant disease burden amongst Māori and Pacific populations in New Zealand (NZ). However, contemporary data are lacking regarding circulating group A Streptococcal (GAS) strains in NZ. Such information is important in guiding vaccine development.
Methods:
GAS isolates from April to June 2015 were recovered from skin and pharyngeal samples from children living in areas of high social deprivation in Auckland, NZ, a significant proportion of which are Māori or Pacific. These children are among the highest risk group for developing ARF. Isolates were compared to concurrently collected pharyngeal isolates from Dunedin, NZ, where both the proportion of Māori and Pacific children and risk of developing ARF is low. Emm typing, emm cluster typing and theoretical coverage of the 30-valent vaccine candidate were undertaken as previously described.
Results:
A high diversity of emm types and a high proportion of emm-pattern D and cluster D4 isolates were detected amongst both skin and pharyngeal isolates in children at high risk of ARF. Pharyngeal isolates from children at low risk of ARF within the same country were significantly less diverse, less likely to be emm pattern D, and more likely to be theoretically covered by the 30-valent M protein vaccine.
Conclusions:
The high proportion of emm pattern D GAS strains amongst skin and pharyngeal isolates from children at high risk of ARF raises further questions about the role of skin infection in ARF pathogenesis. Emm types and emm clusters differed considerably between ARF endemic and non-endemic settings, even within the same country. This difference should be taken into account for vaccine development.
Insights
Group A Streptococcus strains in New Zealand show high diversity in high-risk populations for acute rheumatic fever (ARF). These findings are crucial for developing effective ARF vaccines.
Area of Science:
- Microbiology
- Epidemiology
- Vaccinology
Background:
- Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) disproportionately affect Māori and Pacific peoples in New Zealand.
- Current data on circulating Group A Streptococcus (GAS) strains in New Zealand are limited, hindering vaccine development.
Purpose of the Study:
- To investigate the diversity of GAS strains in high-risk populations in New Zealand.
- To inform the development of a GAS vaccine by characterizing circulating strains.
Main Methods:
- GAS isolates were collected from skin and pharyngeal samples of children in Auckland (high-risk) and Dunedin (low-risk) between April and June 2015.
- Emm typing, emm cluster typing, and assessment of theoretical coverage by a 30-valent vaccine candidate were performed.
Main Results:
- High diversity of emm types and a prevalence of emm-pattern D and cluster D4 isolates were found in both skin and pharyngeal samples from high-risk children.
- Pharyngeal isolates from low-risk children exhibited less diversity, were less likely to be emm pattern D, and had higher theoretical vaccine coverage.
Conclusions:
- The prevalence of emm pattern D GAS strains in high-risk children suggests a potential role for skin infections in ARF pathogenesis.
- Significant differences in emm types and clusters between ARF-endemic and non-endemic settings within New Zealand necessitate consideration in vaccine design.
