Identification and sequencing of bacterial rDNAs in culture-negative amniotic fluid from women in premature labor.
Our objective was to identify bacterial species present in culture-negative but 16S rDNA-positive amniotic fluid samples from women in preterm labor. Amniotic fluid from 69 women in preterm labor was cultured and examined for the proinflammatory cytokine interleukin-6 (IL-6). Polymerase chain reaction technology was used to detect highly conserved bacterial ribosomal DNA sequences (16S rDNAs). As previously reported, 16S rDNAs were identified in 15 (94%) of 16 culture-positive amniotic fluid samples, in 5 (36%) of 14 culture-negative samples with elevated IL-6, and in 1 (3%) of 39 culture-negative samples with low IL-6 levels. Direct sequencing was performed of 16S rDNAs from the 5 culture-negative amniotic fluid specimens with elevated IL-6, followed by database searches and phylogenetic analyses. The bacterial sequences identified included: two Leptotrichia sanguinegens, one human oral bacterium A33, one Fusobacterium nucleatum, and one Ureaplasma urealyticum. Identification and sequencing of 16S rDNAs in amniotic fluid is a promising technique to identify bacterial species associated with elevated IL-6 levels in culture-negative amniotic fluid that may contribute to the etiology of premature labor.
Department of Obstetrics and Gynecology, University of Washington, and VA Medical Center, Seattle, Washington 98195, USA.
Carolyn
C
Gardella
Donald E
DE
Riley
Jane
J
Hitti
Kathy
K
Agnew
John N
JN
Krieger
David
D
Eschenbach
D000328:Adult; D000653:Amniotic Fluid / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis*; D004275:DNA, Ribosomal / Q000032:analysis*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis; D007752:Obstetric Labor, Premature / Q000382:microbiology* / Q000517:prevention & control; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D015850:Interleukin-6; D012336:RNA, Ribosomal, 16S; D014409:Tumor Necrosis Factor-alpha