Performance Assessment of the GenomEra^TM Assay in DetectingGroup B Streptococcus in Vaginal and Rectal Samples

Background: Group B streptococcus (GBS), is one of the principal causes of severe neonatal infections. The most important risk factor for EOGBS is thevaginal colonization causing vertical transmission of bacteria to the infantduring labor and delivery. Identification of pregnant women colonizedwith GBS is essential in the prevention of early onset neonatal sepsis(EOGBS). The current culture-based methodfor detection of GBS is lesssensitive and time-consuming. Multiple assays have been developed inorder to establish rapid and efficient screening test for detection of GBS.Objective: To evaluate the performance of a PCR assay, the GenomEraTM GBS assay (Abacus Diagnostica, Finland), as a direct and rapid method for detectionof GBS in vaginal or rectal samples, by using the culture-based methodas reference.Methods: One hundred fifty-nine (159) unidentified vaginal and rectal sampleswere selected on the basis of culturing-results obtained from the clinicaldepartment of microbiology at Karolinska University Hospital. Sampleswere directly (without prior enrichment) analyzed with the GenomEraTMGBS assay.Results: The PCR assay resulted inthe sensitivity of 83.9% and the specificity of94.9%, with aPPV and the NPV of 91.2% and 90.2%, respectively. Theassay had a turnaround time of 1 hour.Conclusion: The PCR assay provides a rapid alternative for screening of women for GBSduring the delivery, thus enabling targeted prophylaxis of GBS positivemothers.