title: Detection of bacteria in placental tissues obtained from extremely low gestational age neonates.
abstract: OBJECTIVE
  The objective of the study was to quantify and identify aerobic and anaerobic bacteria as well as Mycoplasma and Ureaplasma in the chorionic parenchyma.
  
  
  METHODS
  A sample of the chorionic parenchyma from neonates delivered between 23-27 completed weeks was cultured and tested by polymerase chain reaction (PCR) methods using universal bacterial primers for the presence of bacteria and mycoplasmas.
  
  
  RESULTS
  The culture positive rate was higher for vaginal deliveries (333/489; 68%) than for cesarean sections (363/876; 41%). Thirty percent of all culture-positive samples had only aerobic bacteria, 21% of the samples had only anaerobic bacteria, and 9% of the samples had only Mycoplasma/Ureaplasma. The mean concentration of Mycoplasma/Ureaplasma (4.00 +/- 1.11 log10 CFU/g) was significantly higher (P < .001) than the total count of either aerobes (3.24 +/- 1.12 log10 CFU/g) or anaerobes (2.89 +/- 0.99 log10 CFU/g). Staphylococcus sp. and Corynebacterium sp. as well as organisms associated with bacterial vaginosis were the most frequently recovered. A PCR product was not detected from either randomly selected or known culture-positive samples.
  
  
  CONCLUSIONS
  Approximately half of second-trimester placentas harbor organisms within the chorionic plate. The chorion parenchyma appears to harbor constituents that prevent the identification of bacterial deoxyribonucleic acid by PCR methods.
authors.affiliation: Harvard Medical School and the Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Onderdonk
authors.forename: Mary L
authors.initials: ML
authors.lastname: Delaney
authors.forename: Andrea M
authors.initials: AM
authors.lastname: DuBois
authors.forename: Elizabeth N
authors.initials: EN
authors.lastname: Allred
authors.forename: Alan
authors.initials: A
authors.lastname: Leviton
mesh_terms: D000293:Adolescent; D000328:Adult; D001420:Bacteria, Aerobic / Q000302:isolation & purification; D001421:Bacteria, Anaerobic / Q000302:isolation & purification; D015331:Cohort Studies; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008875:Middle Aged; D009174:Mycoplasma / Q000302:isolation & purification*; D010920:Placenta / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016990:Ureaplasma urealyticum / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial