The Application of Realtime Fluorescence Quantitative PCR for Prenatal Screening of Group B Streptococcal Infections

Changzhi Xu (Department of Laboratory Medicine, The Third Affliated Hospital of Sun Yat-sen University)
Donglin Zhu (Department of Laboratory Medicine, The Third Affliated Hospital of Sun Yat-sen University)
Zhizhi Xie (Department of Laboratory Medicine, The Third Affliated Hospital of Sun Yat-sen University)
Yun Xi (Department of Laboratory Medicine, The Third Affliated Hospital of Sun Yat-sen University)

Article ID: 669


Objective: In the prenatal screening, several different methods were used to detect the presence of group B streptococcus (GBS) infection, in this assay, the diagnostic value and clinical signifcance of the application of realtime fluorescent PCR were explored. Methods: A total of 86 women with 35-37 weeks pregnancy were enrolled, vaginal secretion samples were collected. Fluorescence PCR, bacterial culture and gene sequencing were used to detect whether there was GBS infection, and the results obtained were compared and analyzed. Results: 10 subjects were detected to be positive for GBS by fluorescence PCR (the positive rate was 11.6%), however, only 4 cases were positive for GBS by bacterial culture method (the positive rate was 4.7%). There was a statistically signifcant difference in the positive rate between the two methods (P<0.01). Compared with the results of gene sequencing, the detection of GBS infection by fluorescence PCR has an accuracy of 95.2%, and the sensitivity was 90.9% with 100% specificity. Conclusion: The application of realtime fluorescence quantitative PCR for the detection of GBS infection is signifcantly better than the use of bacterial culture method. Compared with the gold standard method (gene sequencing method), its detection effciency, accuracy, sensitivity and specifcity are relatively high. In summary, PCR for prenatal screening of GBS is worthy of promotion in clinical practice.


Streptococcus B; Fluorescence quantitative PCR; Bacterial culture; Gene sequencing

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