Diversity of microbes in amniotic fluid

Phylum-level distribution of the bacterial taxa detected in studies that used broad-range polymerase chain reaction methods to assay amniotic fluid in the setting of either preterm labor with intact membranes or of preterm premature rupture of the membranes (PROM). Only studies that reported findings in a manner that enabled taxonomic analysis of all subjects are included.

Genus-level rank abundance curves of bacterial prevalence based on studies that used broad-range polymerase chain reaction (PCR) to assay amniotic fluid. (A) All 21 taxa reported in studies of women in preterm labor with intact membranes. (B) The 18 taxa that were detected in two or more subjects in studies of women with preterm premature rupture of the membranes; 21 additional taxa detected in one subject apiece are not shown (Actinomyces, Atopobium, Brachybacterium, Campylobacter, Clostridium, Coprobacillus, Dialister, Eikenella, Eubacterium, Faecalibacterium, Filifactor, Finegoldia, Kingella, Klebsiella, Mobiluncus, Myroides, Neisseria, Rothia, †uncultured Clostridiaceae (clone 209-b07), †uncultured Clostridiaceae (clone 209-b10), and †TM-7 like). Only studies that reported findings in a manner that enabled taxonomic analysis of all subjects are included. *The two subjects with Escherichia species were positive by both PCR and culture; in both cases, Escherichia assignment is based on culture findings because the 16S rDNA gene is unreliable for differentiating between the genera Escherichia and Shigella. †Denotes the taxa that could not be classified to genus-level resolution, owing to current limitations of reference sequence databases.

Kaplan–Meier survival analysis of the amniocentesis-to-delivery interval according to results of polymerase chain reaction (PCR) and culture of amniotic fluid from four separate studies of two clinical phenotypes [preterm labor with intact membranes, or preterm premature rupture of the membranes (PROM)]. (A and B) Studies that used taxon-specific PCR assays to detect Ureaplasma spp. (C and D) Studies that used broad-range PCR assays. Sources: (A) Yoon et al.¹⁸; Courtesy of Elsevier (B) Yoon et al.¹⁹; Courtesy of Elsevier (C) DiGiulio et al.²⁷; (D) DiGiulio et al.³¹ Courtesy of John Wiley.