title: Culture and Real-Time PCR Based Maternal Screening and Antibiotic Susceptibility for Group B Streptococcus: An Iranian Experience.
abstract: BACKGROUND
  Vertical Transmission of group B streptococcus (GBS) from a vagina colonized mother to her infant upon rupture of membranes (ROM) or after the onset of labor can cause life-threatening infections in newborn. Although intrapartum antibiotic prophylaxis (IAP) can significantly decrease neonatal GBS diseases, this issue has potentiated the emergence of antibiotic resistance strains. Our study examined the colonization rate of GBS using real-time PCR and culture methods, and trends in antibiotic resistance of GBS isolates obtained from pregnant women in Khorramabad, Iran.
  
  
  METHODS
  In this cross-sectional study, two vaginal-rectal swabs were collected and analyzed separately from 100 pregnant women at 35-37 weeks of gestation by convenience sampling method. The specimens were subjected to GBS detection using real-time PCR assay and standard culture. Susceptibility pattern of the GBS isolates was examined using the disk diffusion method.
  
  
  RESULTS
  GBS carriage rate was 17% and 19% using culture and real-time PCR, respectively. In six samples, the culture was positive and the real-time PCR was negative. Sensitivity and specificity for real-time PCR were 72.7% and 96.1%, respectively using culture as the gold standard. Amongst twenty-two isolates examined, 100% resistance to erythromycin and clindamycin was observed. One isolate (4%) exhibited resistance to penicillin.
  
  
  CONCLUSIONS
  Considering the relatively high GBS carriage rate in Khorramabad, routine antepartum screening for GBS is recommended. Penicillin can remain the antibiotic of choice for IAP; however, in penicillin-allergic mothers, vancomycin can be an alternative antibiotic.
authors.affiliation: School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran. Goudarzi.gh@gmail.com.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Goudarzi
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Ghafarzadeh
authors.forename: Pegah
authors.initials: P
authors.lastname: Shakib
authors.forename: Khatereh
authors.initials: K
authors.lastname: Anbari
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis; D003430:Cross-Sectional Studies; D052978:Disk Diffusion Antimicrobial Tests; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D007492:Iran; D011237:Predictive Value of Tests; D011247:Pregnancy; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000517:prevention & control*; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents