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Rapid detection of zoonotic Streptococcus suis serotype 2 and 14 by enzyme-activated probe fluorescence quantitative
Yaxing Su1, Jiajia Meng1, Mingwei Zhao1
1College of Veterinary Medicine, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
Abstract:
Streptococcus suis serotypes 2 and 14 are the most common zoonotic strains, but previous identification methods made distinguish these two serotypes from other S. suis serotypes difficult. To effectively prevent and control them, there is an urgent need for a highly sensitive and specific method to identify these two serotypes. In this study, a fluorescent probe was designed for the single nucleotide polymorphism site at cpsK 483 of Streptococcus suis type 2 and type 14 compared with other serotypes, and an enzyme-activated probe quantitative PCR (EA-probe qPCR) method was established for the detection of Streptococcus suis type 2 and type 14 by combining with the specific hydrolysis characteristics of the RNase H2 enzyme. The results showed that the optimal probe concentration for this method was 0.5 µM and the optimal RNase H2 enzyme concentration was 25 mU.This method showed no reactivity with genomic DNA from Streptococcus suis strains 1/2, 5, 7, 9, 23, 28, 29, and 31, confirming its high specificity. And its sensitivity can reach 18.4 CFU. In addition, 19 clinical strains of Streptococcus suis type 2 or type 1/2 were tested. The results showed 100% agreement with the gene sequencing method. In conclusion, this method can meet the needs of accurate laboratory testing of Streptococcus suis serotypes 2 and 14 and has value for clinical prevention.
Insights
A new enzyme-activated probe quantitative PCR method accurately identifies Streptococcus suis serotypes 2 and 14. This highly sensitive and specific technique aids in preventing and controlling these common zoonotic bacterial strains.
Area of Science:
- Microbiology
- Molecular Biology
- Veterinary Science
Background:
- Streptococcus suis serotypes 2 and 14 are significant zoonotic pathogens.
- Distinguishing these serotypes from others using traditional methods is challenging.
- Accurate identification is crucial for effective disease prevention and control.
Purpose of the Study:
- To develop a highly sensitive and specific method for identifying Streptococcus suis serotypes 2 and 14.
- To address the limitations of existing identification techniques for these common zoonotic strains.
Main Methods:
- Design of a fluorescent probe targeting a single nucleotide polymorphism (SNP) at cpsK 483.
- Establishment of an enzyme-activated probe quantitative PCR (EA-probe qPCR) method.
- Utilizing the specific hydrolysis characteristics of the RNase H2 enzyme for detection.
Main Results:
- Optimized probe concentration at 0.5 µM and RNase H2 enzyme concentration at 25 mU.
- Demonstrated high specificity, showing no reactivity with other S. suis serotypes.
- Achieved high sensitivity, detecting as low as 18.4 CFU.
- Showed 100% agreement with gene sequencing for 19 clinical strains.
Conclusions:
- The developed EA-probe qPCR method offers accurate laboratory testing for Streptococcus suis serotypes 2 and 14.
- This method has significant value for clinical prevention and disease management.
- The technique overcomes previous identification challenges, enabling better control of zoonotic S. suis.
