Comparison of 4 commercially available group B Streptococcus molecular assays using remnant rectal–vaginal enrichment broths

Abstract

The incidence of neonatal Group B streptococcal (GBS) disease has significantly declined since the widespread implementation of prenatal screening of expectant mothers for urogenital and gastrointestinal tract GBS colonization. Screening methods have evolved from exclusively culture-based approaches to more rapid and highly sensitive molecular methods. We chose to evaluate the performance of 4 commercially available GBS molecular tests for detection of GBS colonization using 299 antepartum rectal-vaginal specimens submitted to our laboratory for routine GBS screening. In 97% of instances, there was agreement between all 3 systems. When testing 1, 6, and 12 samples simultaneously, all methods performed comparably, but the ARIES® GBS assay required the least total hands-on time and the illumigene Group B Streptococcus assay required the most hands-on time.

Comparison of Three Nucleic Acid Amplification Tests and Culture for Detection of Group B Streptococcus from Enrichment Broth

“…In our study, the agreement among Panther Fusion, Aries and Xpert GBS assays was >97%. Another study found a 97% agreement between four NAATs (BD Max, Illumigene, Aries, and Xpert) (14). The results of this and other studies highlight the underestimation of GBS colonization with broth-enriched culture methods and support the adoption of NAATs as the new gold standard to improve GBS detection.…”

“…Several Food and Drug Administration (FDA)-cleared real-time PCR-based NAATs are currently available for the qualitative detection of GBS in enriched broth cultures. NAATs on sample-to-answer platforms offer standardized processing technology for specimen extraction, amplification, and detection, provide a shorter turnaround time to result, and demonstrate improved GBS detection rates compared to those of culture (13–23).…”

Molecular diagnostic assays for the detection of common bacterial meningitis pathogens: A narrative review

“…Singleplex assays detecting GBS have also been developed, although many of these are optimised for identifying the bacterium from gut or vaginal colonisation and/or shortly after labour rather than for the diagnosis of acute infection [39,40]. Four commercial assays are available: (i) The Becton Dickinson MAX GBS assay; (ii) The ARIES GBS assay from Luminex Corporation; (iii) The Illumigene Group B Streptococcus assay from Meridian Bioscience; and (iv) The Xpert GBS LB assay produced by Cepheid Inc. Three of these use rtPCR assays, while Illumigene uses a loop-mediated isothermal amplification (LAMP) assay with the cfb gene as the primary target.…”

“…Four commercial assays are available: (i) The Becton Dickinson MAX GBS assay; (ii) The ARIES GBS assay from Luminex Corporation; (iii) The Illumigene Group B Streptococcus assay from Meridian Bioscience; and (iv) The Xpert GBS LB assay produced by Cepheid Inc. Three of these use rtPCR assays, while Illumigene uses a loop-mediated isothermal amplification (LAMP) assay with the cfb gene as the primary target. The gene cfb encodes the extracellular pore-forming toxin also known as the CAMP factor [40]. The Christie-Atkinson-Munch-Peterson (CAMP) test has been the conventional culture-based test for identifying GBS and differentiates haemolytic versus non-haemolytic GBS.…”

Detection of group B Streptococcus during antenatal screening in Western Australia: a comparison of culture and molecular methods

“…Culture-based methods remain the gold standard for GBS detection; however, numerous studies have suggested molecular methods, such as PCR, are more sensitive and specific compared to culture and represent a point-of-care detection option (El Helali et al 2009;de-Paris et al 2011;Khalil et al 2017;Wollheim et al 2017;Relich et al 2018). Cost-effectiveness is another consideration when evaluating screening methods, particularly in GBS where universal screening is implemented (Kaambwa et al 2010).…”