title: Rapid diagnostic test for identifying group B streptococcus.
abstract: Neonatal infection with Streptococcus agalactiae (group B streptococcus [GBS]) causes significant morbidity and mortality. A truly rapid diagnostic test for identifying GBS would allow for more timely initiation of antibiotic prophylaxis and also reduce the administration of antibiotics for the prevention of early onset neonatal GBS infection. A stock culture was formed from a laboratory reference strain of GBS and was diluted from 10 (7) to 10 (1) bacteria/mL. Specific concentrations were used to inoculate nitrocellulose membranes (NCMs) that had been coated previously with polyclonal rabbit antibody against GBS. After specific times, the NCMs were removed from the sheep blood agar medium, and horseradish-peroxidase conjugate polyclonal antibody against GBS was added. Bound antibody was detected with diaminobenzidine. After 6 hours of incubation, GBS was detected at concentrations from 10 (7) through 10 (4) bacterial/mL. After 4 hours of incubation, GBS was detected at concentrations from 10 (7) through 10 (5) bacteria/mL. GBS was not detected at 2 hours of incubation. Rapid growth and detection of GBS can be performed, and the results can be reliably attained as early as 4 hours. This is in marked contrast to the 48 to 72 hours required by current methods.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center, Houston, Texas, USA. Jonathan.P.Faro@uth.tmc.edu
authors.forename: Jonathan
authors.initials: J
authors.lastname: Faro
authors.forename: Allan
authors.initials: A
authors.lastname: Katz
authors.forename: Karen
authors.initials: K
authors.lastname: Bishop
authors.forename: Gerald
authors.initials: G
authors.lastname: Riddle
authors.forename: Sebastian
authors.initials: S
authors.lastname: Faro
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D011296:Prenatal Diagnosis / Q000379:methods*; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000635:transmission*; D013292:Streptococcus agalactiae / Q000302:isolation & purification*; D013997:Time Factors