Bacterial 16S rDNA polymerase chain reaction in the detection of intra-amniotic infection

Br J Obstet Gynaecol. 1996 Jul;103(7):664-9. doi: 10.1111/j.1471-0528.1996.tb09835.x.


Objective: Bacterial polymerase chain reaction (PCR) was used to detect early subclinical intraamhiotic infection. We used universal primers which amplify a DNA fragment of 16S ribosomal DNA (rDNA) from all known bacteria and sequenced the positive samples to identify the bacterial species.

Design: Transabdominally obtained amniotic fluid samples from 20 pregnant women with prelabour rupture of the fetal membranes (PROM), showing no signs of clinical infection, and 16 control samples were analysed with universal bacterial PCR. In addition, routine bacterial culture and amniotic fluid glucose were studied.

Results: Out of 20 PROM patients, five were positive in the PCR. PCR detected Ureaplasma urealyticum in two cases, Haemophilus influenzae in one case, Streptococcus oralis in one case and Fusobacterium sp. in one case. Only two of these were positive in a routine bacterial culture. Both were multibacterial infections, which caused discrepancies between the PCR and culture results. Two patients developed infectious complications: both were identified with the PCR assay. Amniotic fluid glucose was lower in PCR positive patients compared with PCR negative patients.

Conclusion: Bacterial 16S rDNA PCR, in properly controlled conditions, promises to be a fast and reliable test for early intra-amniotic infection especially concerning Ureaplasma urealyticum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amniotic Fluid / microbiology*
  • Bacterial Infections / diagnosis*
  • DNA, Bacterial / analysis*
  • DNA, Ribosomal / analysis*
  • Female
  • Fetal Membranes, Premature Rupture / microbiology*
  • Haemophilus Infections / diagnosis
  • Haemophilus influenzae / genetics
  • Haemophilus influenzae / isolation & purification
  • Humans
  • Polymerase Chain Reaction
  • Pregnancy
  • Pregnancy Complications, Infectious / diagnosis*
  • Sensitivity and Specificity
  • Streptococcal Infections / diagnosis
  • Ureaplasma Infections / diagnosis*
  • Ureaplasma urealyticum / genetics
  • Ureaplasma urealyticum / isolation & purification


  • DNA, Bacterial
  • DNA, Ribosomal