A new rapid and cost-effective method for detection of phages, ICEs and virulence factors encoded by Streptococcus
Anna L Borek1, Joanna Wilemska, Radosław Izdebski
1Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland.
Abstract:
Streptococcus pyogenes (group A Streptococcus, GAS) is a human pathogen that causes diseases of various intensity, from mild strep throat to life threatening invasive infections and postinfectional sequelae. S. pyogenes encodes multiple, often phage encoded, virulence factors and their presence is related to severity of the disease. Acquisition of mobile genetic elements, carrying virulence factors, as phages or ICEs (integrative and cojugative elements) has been shown previously to promote selection of virulent clones. We designed the system of eight low volume multi- and one singleplex PCR reactions to detect genes encoding twenty virulence factors (spd3, sdc, sdaB, sdaD, speB, spyCEP, scpA, mac, sic, speL, K, M, C, I, A, H, G, J, smeZ and ssa) and twenty one phage and ICE integration sites described so far for S. pyogenes. Classification of strains based on the phage and virulence factors absence or presence, correlates with PFGE MLST and emm typing results. We developed a novel, fast and cost effective system that can be used to detect GAS virulence factors. Moreover, this system may become an alternative and effective system to differentiate between GAS strains.
Insights
This study introduces a new PCR method to detect virulence factors in Streptococcus pyogenes (group A Streptococcus). This rapid, cost-effective system aids in differentiating GAS strains and understanding disease severity.
Area of Science:
- Microbiology and Infectious Diseases
- Molecular Biology and Genetics
Background:
- Streptococcus pyogenes (group A Streptococcus, GAS) is a significant human pathogen causing a spectrum of illnesses, from mild pharyngitis to severe invasive infections.
- Virulence factors, often encoded by mobile genetic elements like phages and integrative conjugative elements (ICEs), play a crucial role in GAS pathogenicity and disease severity.
- Existing methods for strain differentiation and virulence factor detection can be time-consuming and costly.
Purpose of the Study:
- To develop a novel, rapid, and cost-effective multiplex PCR system for the simultaneous detection of multiple GAS virulence factor genes.
- To identify and characterize phage and ICE integration sites associated with S. pyogenes virulence.
- To establish a system for differentiating GAS strains based on their virulence factor and mobile genetic element profiles.
Main Methods:
- Design and implementation of eight low-volume multiplex PCR and one singleplex PCR reactions.
- Detection of genes encoding twenty specific virulence factors (e.g., speB, spyCEP, scpA) and twenty-one known phage/ICE integration sites in S. pyogenes.
- Correlation of PCR-based classification with established typing methods such as PFGE, MLST, and emm typing.
Main Results:
- A comprehensive PCR system was successfully developed to detect twenty GAS virulence factors and twenty-one mobile genetic element integration sites.
- Strain classification based on the presence or absence of detected virulence factors and integration sites showed strong correlation with PFGE, MLST, and emm typing data.
- The developed system provides a fast and cost-effective means for identifying GAS virulence determinants.
Conclusions:
- The novel multiplex PCR system offers an efficient and effective tool for detecting Streptococcus pyogenes virulence factors.
- This system serves as a valuable alternative for differentiating GAS strains, aiding in epidemiological surveillance and understanding pathogen evolution.
- The findings highlight the importance of mobile genetic elements in shaping GAS virulence and disease potential.
Related Concept Videos
01:24Automated Microbial Diagnostics
01:28Methods of Classification and Identification