title: [Optimization of screening methodologies for the detection of Streptococcus agalactiae in pregnant women].
abstract: Streptococcus agalactiae is a significant worldwide cause of morbidity and mortality in pregnant women and their newborn infants. The objective of this work was to determine the usefulness of bioMerieux chromogenic medium chromID Strepto B (CR) for detecting S. agalactiae in pregnant women from the selective Todd-Hewitt broth (sel-THB ) against the methods proposed by the CDC . A total of 1924 swabs were analyzed, 962 from vaginal introitus and 962 rectal, belonging to 962 women in weeks 35-37 of pregnancy. The swabs were directly seeded in CR. Both swabs were later placed in sel-THB with 15 µg/ml supplement of nalidixic acid and 10 µg/ml colistin. After 24 h of incubation, subcultures in CR medium and agar containing 5% sheep blood (SBA) were performed. The prevalence found was 17.4%. Sensitivity, specificity, positive and negative predictive values of sel-THB subcultures with CR supplement and 48 h incubation were: 98.8, 100, 100 and 99.7%, respectively. The corresponding values of direct harvest of the sample were 57.8, 100, 100, and 90%, respectively. Sensitivity of sel-THB in SBA was 85%. Sel-THB subculture performance in CR was outstanding in comparison with the method proposed by the CDC.
authors.affiliation: Laboratorio de Bacteriología, Hospital Juan A. Fernández, Ciudad Autónoma de Buenos Aires.
authors.forename: Silvia E
authors.initials: SE
authors.lastname: Montibello
authors.forename: Liliana I
authors.initials: LI
authors.lastname: Guelfand
authors.forename: Mónica G
authors.initials: MG
authors.lastname: Machaín
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Carrión
authors.forename: María D
authors.initials: MD
authors.lastname: Ferreira
authors.forename: Juan C
authors.initials: JC
authors.lastname: Pidone
authors.forename: María E
authors.initials: ME
authors.lastname: Ceregido
authors.forename: Sara C
authors.initials: SC
authors.lastname: Kaufman
authors.forename: Rolando N
authors.initials: RN
authors.lastname: Soloaga
mesh_terms: D001118:Argentina / Q000453:epidemiology; D001431:Bacteriological Techniques; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D002863:Chromogenic Compounds / Q000032:analysis; D003470:Culture Media; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000382:microbiology / Q000517:prevention & control; D011263:Pregnancy Trimester, Third; D015995:Prevalence; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012007:Rectum / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology / Q000517:prevention & control; D013292:Streptococcus agalactiae / Q000254:growth & development / Q000302:isolation & purification* / Q000472:pathogenicity; D013696:Temperature; D014621:Vagina / Q000382:microbiology*
chemical_list: D002863:Chromogenic Compounds; D003470:Culture Media; D011933:Reagent Kits, Diagnostic