Detection of Group B Streptococcus agalactiae from Anorectal and Vaginal Screening Tests

Abstract

Objective: The aim of the present study was to analyze two DNA extraction methods for use in molecular GBS diagnostics and compare them to the results of culture method.Materials and methods: Two hundred vaginal samples were collected during the antenatal period, as per CDC recommendations, and atr gene polymerase chain reaction (PCR) was performed.Results: Comparison of the two DNA extraction methods demonstrated 45% concordance. Sensitivity and specificity for 5 M Guanidine DNA extraction were 100% and 86.5%, respectively. Sensitivity and specificity for the commercial DNA extraction kit were 50% and 95%, respectively.Conclusion: This study demonstrated that 5 M Guanidine DNA extraction was superior to the commercial kit, with PCR presenting a shorter turnaround time than culture. PCR could improve sensitivity and, therefore, may be a useful screening method. Sensitive GBS diagnosis allows for an effective treatment, with decreased newborn morbidity and mortality; therefore, cost-effectiveness studies are necessary to assess the feasibility of implementing PCR in routine laboratories, together with maternity ward collaboration.