Abstract:
Objective To compare two PCR assays based on cfb and scpb genes for the detection of Streptococcus agalactiae, and establish a rational real-time quantitative PCR (qPCR) detection system to detect S. agalactiae rapidly.
Methods The sensitivity and specificity of cfb and scpb genes were compared and verified by PCR amplification of 60 clinical isolated strains of S. agalactiae and 15 strains of non-S. agalactiae, and the genes with better detection performance were selected as targets to establish a real-time quantitative PCR detection system. Then, 100 clinical specimens, such as cervical swabs and semen, were detected by qPCR and compared with the traditional culture method. Chi-square test was used to compare the positive rates, and P＜0.05 was considered statistically significant.
Results The specificity of both cfb and scpb genes were 100%, and the sensitivity were 98.3% and 66.7%, respectively. The difference was statistically significant (P＜0.005). The positive rate of GBS detected by real-time PCR and culture were 35% and 30% respectively, which has no statistical difference. However, 7 samples of the 100 samples were amplified positive by real-time PCR positive, but the S. agalactiae was not isolated.
Conclusion The detection of GBS by real-time PCR method targeting cfb gene was direct, rapid, simple, high specificity. And the sensitivity of the real-time PCR was higher than conventional culture method, so that the method can be applied to the detection of various clinical samples, and has great application prospect in clinic.
Key words:
Streptococcus agalactiae,
real-time PCR,
cfb gene,
scpb gene
Yasha Luo, Yitong Zhang, Liang Zhang, Qiuping Chen, Biting Li, Xiaoping Mu. Comparison and clinical application of cfb and scpb genes in PCR assays to detect Streptococcus agalactiae[J]. Chinese Journal of Clinical Laboratory Management(Electronic Edition), 2021, 09(01): 38-41.