Evaluation of Enrichment Combined with PCR or MALDI-TOF for the Detection of Streptococcus agalactiae Infection or Carriage in Late Pregnancy or in Elderly Patients

The rapid and reliable detection of Streptococcus agalactiae is essential for preventing severe neonatal and elderly infections, where timely diagnosis directly influences clinical management. This study evaluated SIGMA-GBS™ enrichment transport devices for their ability to support downstream identification using culture and multiple rapid diagnostic platforms, including BD MAX™ PCR, MALDI-TOF (Vitek MS), direct latex agglutination, and chromogenic agar culture. Clinical isolates were inoculated onto foam and PurFlock® swabs, incubated overnight in SIGMA-GBS™ medium, and then processed using standard laboratory workflows. Results demonstrated successful recovery and identification of S. agalactiae across both dilution ranges and swab types, with 47 of 48 samples correctly detected; the single negative result was attributed to a processing error. PCR and MALDI-TOF consistently confirmed organism identity, and chromogenic culture supported enrichment performance. Overall, SIGMA-GBS™ enabled effective enrichment and reliable detection across multiple diagnostic platforms, supporting its utility as an integrated transport and enrichment system that can streamline laboratory workflows and facilitate faster confirmation of S. agalactiae in routine screening and diagnostic settings.