Comparison of commercially available group B streptococcal latex agglutination assays

Detection of group B streptococcus (GBS) antigen in urine by latex particle agglutination (LPA) may facilitate the rapid diagnosis of GBS sepsis. We sought to compare three commercial LPA assays with specimens that were spiked with type-specific antigen, group-specific antigen, or type III organisms. There were sensitivity differences between the assays, but the Bactigen assay performed best, detecting as little as 1 ng of GBS group-specific antigen per ml in urine and as few as 105 CFU of GBS type III organisms per ml in urine, serum, and cerebrospinal fluid. Streptococcus agalactiae, the group B streptococcus (GBS), is the major cause of neonatal sepsis and meningitis in the United States (1). Detection ofGBS antigen in urine or other body fluids by latex particle agglutination (LPA) may facilitate the rapid diagnosis of GBS sepsis. GBS LPA assays have been reported to be 88 to 100 % sensitive and 8