Group B Streptococcus detection: comparison of PCR assay and culture as a screening method for pregnant women

• Published in: The Brazilian journal of infectious diseases Vol. 15; no. 4; pp. 323 - 327
• Main Authors: de-Paris, Fernanda, Pinheiro Machado, Alice Beatriz Mombach, Gheno, Tailise Conte, Ascoli, Bruna Maria, de Oliveira, Kátia Ruschel Pilger, Barth, Afonso Luis
• Format: Journal Article
• Language: English
• Published: Brazil Elsevier Editora Ltda 01-07-2011; Contexto; Elsevier
• Subjects: culture; Culture Media; DNA Primers - analysis; DNA, Bacterial - analysis; Female; Health aspects; Humans; Infection; Methods; Polymerase Chain Reaction; Predictive Value of Tests; Pregnancy; Pregnancy Complications, Infectious - diagnosis; Pregnancy Complications, Infectious - microbiology; Pregnant women; Prevalence studies (Epidemiology); Reagent Kits, Diagnostic; Rectum - microbiology; Sensitivity and Specificity; Streptococcal Infections - diagnosis; Streptococcal Infections - microbiology; Streptococcus agalactiae; Streptococcus agalactiae - genetics; Streptococcus agalactiae - isolation & purification; Vagina - microbiology; Brazil; Streptococcus agalactiae; culture; polymerase chain reaction; pregnancy
• ISSN: 1413-8670; 1678-4391
• DOI: 10.1016/S1413-8670(11)70199-4

Streptococcus agalactiae or group B Streptococcus (GBS) is one of the most important causal agents of serious neonatal infections. Numerous assays have been evaluated for GBS screening in order to validate a fast and efficient method. The aim of this study was to compare the culture technique (established as the gold standard) with the molecular method of polymerase chain reaction (PCR) with specific primers (atr gene). Two hundred and sixty-three samples were analyzed. Vaginal samples were collected, according to the Centers for Disease Control and Prevention (CDC) recommendations, from women over 35 weeks of pregnancy at Hospital de Clínicas de Porto Alegre (HCPA). Two different extraction methods were tested in all samples collected. PCR technique yielded 71 (26.99%) positive results. Sensitivity and specificity for PCR were 100% and 86.88%, respectively. PCR demonstrated a shorter turnaround time than the culture. The molecular methodology proved to be a useful screening for GBS, allowing effective treatment to be initiated in shorter time to prevent newborn infection.