Group B Streptococcus (GBS) infection is a leading cause of sepsis and meningitis among newborns. The CDC estimates that 25% of pregnant women are asymptomatically colonized with GBS in the genital and rectal mucous membrane sites1. Vertical transmission of GBS to the newborn can result in an invasive infection known as early onset disease (EOD). Infants with EOD will present with fever, lethargy, sepsis, pneumonia and more rarely, meningitis within the first 24 to 48 hours of life.1
The screening of pregnant women for GBS colonization at 35 to 37 weeks gestation and intrapartum antibiotic prophylaxis for colonized women have substantially decreased the risk of GBS transmission to the newborn thus reducing the occurrence of EOD.2 The 2010 CDC guidelines recommend an 18 to 24 hour broth enrichment of a vaginal-rectal swab prior to detection of GBS.3 The use of selective enrichment broth such as Lim broth can increase the detection of GBS by 50% compared to non-enriched methods.3,4 The conventional means for identifying GBS is through culture on blood agar plates followed by a confirmation test, which can be labor intensive.3 Molecular testing provides a streamlined workflow to reduce turnaround time and labor costs.
1. Centers for Disease Control and Prevention. (2018). Group B Strep Fast Facts. Retrieved from https://www.cdc.gov/groupbstrep/about/fast-facts.html.
2. Teatero, S., Ferrieri, P., Martin, I., Demczuk, W., McGeer, A., & Fittipaldi, N. (2017). Serotype Distribution, Population Structure, and Antimicrobial Resistance of Group B Streptococcus Strains Recovered from Colonized Pregnant Women. J. Clin. Microbiol, 55(2), 412-422.
3. Centers for Disease Control and Prevention. (2010). Prevention of Perinatal Group B Streptococcal Disease Revised Guidelines from CDC, 2010. MMWR, 59, No. RR-10.
4. Philipson, E.H., Palermino, D.A., & Robinson, A. (1995). Enhanced antenatal detection of group B Streptococcus colonization. Obstet Gynecol, 85, 437–9, 144.
Why to choose it
A CLIA moderate complexity, real-time PCR assay for the in vitro detection of Group B Strep from Lim broth enriched vaginal/rectal swabs. The assay is high performing with a 97% sensitivity and greater than 96% specificity. The Simplexa® GBS Direct assay also eliminates the need to subculture and perform additional confirmation tests.
Reliable performance that you can count on
The Simplexa® GBS Direct assay demonstrated excellent clinical agreement against traditional culture methods.
Simplexa® GBS Direct Clinical Agreement Study
|Sample TypeSample Type||Sensitivity||Specificity|
|Sample TypeLim broth enriched vaginal/rectal swabs||Sensitivity97.0% (97/100)a
95% CI: 91.5% to 99.0%
95% CI: 93.4% to 97.7%
|a3/3 samples with discrepant results were negative when tested with an alternate FDA cleared NAAT.
b11/13 samples with discrepant results were positive when tested with an alternate FDA cleared NAAT.
Fast Turn-Around Time
Our Simplexa® GBS Direct assay takes only about an hour to generate high-quality results after Lim broth enrichment. A simple and easy workflow enables the assay to be run on any shift and bypass conventional DNA extraction procedures. The Simplexa® GBS Direct assay eliminates the need to subculture and perform additional confirmation tests.
Simplexa® GBS Direct Kit
|Code MOL3550||Reactions 24|
Simplexa® GBS Positive Control Pack
|Code MOL3560||Reactions 10|