title: Accuracy of an accelerated, culture-based assay for detection of group B streptococcus.
abstract: OBJECTIVE
  To determine the validity of a novel Group B Streptococcus (GBS) diagnostic assay for the detection of GBS in antepartum patients.
  
  
  METHODS
  Women were screened for GBS colonization at 35 to 37 weeks of gestation. Three vaginal-rectal swabs were collected per patient; two were processed by traditional culture (commercial laboratory versus in-house culture), and the third was processed by an immunoblot-based test, in which a sample is placed over an antibody-coated nitrocellulose membrane, and after a six-hour culture, bound GBS is detected with a secondary antibody.
  
  
  RESULTS
  356 patients were evaluated. Commercial processing revealed a GBS prevalence rate of 85/356 (23.6%). In-house culture provided a prevalence rate of 105/356 (29.5%). When the accelerated GBS test result was compared to the in-house GBS culture, it demonstrated a sensitivity of 97.1% and a specificity of 88.4%. Interobserver reliability for the novel GBS test was 88.2%.
  
  
  CONCLUSIONS
  The accelerated GBS test provides a high level of validity for the detection of GBS colonization in antepartum patients within 6.5 hours and demonstrates a substantial agreement between observers.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Texas Health Science Center, 6411 N Fannin Street, Houston, TX 77030, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Faro
authors.forename: Karen
authors.initials: K
authors.lastname: Bishop
authors.forename: Gerald
authors.initials: G
authors.lastname: Riddle
authors.forename: Mildred M
authors.initials: MM
authors.lastname: Ramirez
authors.forename: Allan R
authors.initials: AR
authors.lastname: Katz
authors.forename: Mark A
authors.initials: MA
authors.lastname: Turrentine
authors.forename: Sebastian
authors.initials: S
authors.lastname: Faro
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis; D001431:Bacteriological Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000382:microbiology; D011263:Pregnancy Trimester, Third; D012007:Rectum / Q000382:microbiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000302:isolation & purification*; D014621:Vagina / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial