The results of using the real-time PCR method for examination of the placental microbial landscape

Abstract

Aim to study the microbiome of the placenta in full-term pregnancy with premature rupture of the membranes (PROM) in comparison with the intact membranes.
 Material and methods. The study was conducted on the basis of Samara City Clinical Hospital N 1 named after N.I. Pirogov and involved 43 pregnant women at 37-41 weeks of gestation subject to elective cesarean section. The patients were divided in two groups: the main group included 24 women with PROM, the control group was formed with 19 women with intact fetal membranes. The placental tissues were taken for the real-time PCR-test for the following microorganisms: Lactobacillus spp., Enterobacteriaceae, Streptococcus spp., Staphylococcus spp., Gardnerella vaginalis / Prevotella bivia / Porphyromonas spp., Eubacterium spp., Sneathia spp. / Leptotrihia spp. / Fusobacterium spp., Megasphaera spp. / Veillonella spp. / Dialister spp., Lachnobacterium spp. / Clostridium spp., Mobiluncus spp. / Corynebacterium spp., Peptostreptococcus spp., Atopobium vaginae, Mycoplasma hominis, Ureaplasma (urealyticum + parvum), Candida spp., Mycoplasma genitalium.
 Results. At the end of physiological full-term pregnancy, the bacterial population was detected in 66.7% of placentas in the main group, total bacterial count Ме 103,2 Q1:Q3 0,0 103,4 GE/sample; and in 78.9% of the placentas in the control group, total bacterial count Ме 103,3 Q1:Q3 103,1 103,5 GE/sample. The main representatives of the identified microorganisms were Enterobacteriaceae spp. (Me 103,2 GE/sample for PROM and Me 103,2 GE/sample for intact amniotic sac (p0.05)). Lactobacillus spp. were determined in the placenta only in the PROM group in 8.3% of patients. The presence of Lactobacillus spp. in the tissues of the placenta is typical only for patients with PROM. Microorganisms not identified by the Femoflor-16 test were found in 50% of patients with PROM, Me 102,1 GE/sample, and in 63.2% of patients with an intact fetal bladder, Me 103,2 GE/sample, (p = 0.09). No correlation was found between PROM incidents and the characteristics of the placental microbiota.
 Conclusion. In case of physiologically proceeding full-term pregnancy, it is possible to detect using the real-time PCM test a bacterial population represented by the Enterobacteriaceae spp., while in cases of PROM, Lactobacillus spp. and anaerobic vaginal flora were also detected in placental samples.