Bacteria present in human placental samples Targeted loci. Bacteria

This study focused exclusively on placentas obtained through cesarean delivery at term, utilized multiple modes of microbiology inquiry, and incorporated rigorous technical controls. Cultivation, 16S rRNA gene analyses, and metagenomic sequencing were used to characterize the bacterial profiles of placental tissues and to compare them to the profiles of technical controls (e.g. blank extraction kits). Genomic DNA was obtained from the amnion and chorion, and the villous tissue and basal plate layers of placentas, as well as technical controls. The V4 region of 16S rRNA genes in samples was sequenced using Illumina MiSeq, and quantitative real-time PCR (qPCR) was used to compare the abundances of 16S copies among samples. Metagenomic DNA of a subset of placental and technical control samples was sequenced by Illumina HiSeq 4000.