The Changes Of Postpartum Vaginal Flora Were Analyzed By16rRNA High-throughput Sequencing

Aim1.Illumina Hi Seq2500 high-throughput sequencing platform was used to analyze the composition of vaginal flora before and after vaginal delivery and at 42 days postpartum.2.The postpartum vaginal flora information at 42 days was used to predict the maternal postpartum adverse outcomes.Methods1.The research object:Pregnant women who underwent obstetric examination and gave birth naturally in Shenzhen Luohu Maternal and Child Health Hospital from September 2020 to October 2020,A total of 24 pregnant women who met the inclusion and exclusion criteria signed an informed consent form upon admission.The inclusion criteria include:(1)Chinese nationality;(2)Singletons;(3)Gestational age of delivery ≥37 weeks;(4)Vaginal delivery.Exclusion criteria: (1)History of gastrointestinal tract,diabetes mellitus,hypertension,and other immune diseases;(2)Complications such as gestational diabetes Mellitus,hypertension,hyperthyroidism and hypothyroidism and premature rupture of membranes;(3)History of antibiotic use,vaginal medication and lavage during pregnancy and after delivery.This study has been approved by Shenzhen Luohu Maternal and Child Health Hospital.All participants received a written informed consent,and then collected through interviews and consult medical chart of demographic and clinical characteristics of all participants,including gestational age,BMI,weight,age,before delivery and before childbirth prenatal information,history of motherhood,disease history and genital tract disease history,medication history,and presence of complications during pregnancy or complications,etc2.Specimens were collected,sequenced and analyzed Vaginal secretions from the vaginal fornix or the lateral wall of the middle part of the vagina were collected by sterile cotton swabs before delivery(when hospitalized),after delivery(before the delivery room)and 42 days after delivery.The above samples were first placed in a household refrigerator at-4℃,and then transferred to a refrigerator at-80℃ for preservation until DNA extraction.The 16 Sr RNA of vaginal swab samples was amplified by PCR using common bacterial primers.The PCR end product was sequenced by Illumina Hi Seq2500 platform,and the high-throughput original base sequence was obtained.The data were analyzed by QIIME analysis process combined with clinical information.QIIME biological analysis mainly includes the operation classification unit(the Operational Taxonomy Units,the formation of OTU principal coordinate analysis(principal co-ordinates analysis PCo A),flora characteristic analysis,species richness,community structure of alpha and beta diversity analysis,etc.,the alpha diversity with flora structure is calculated by the Shannon diversity index,beta diversity through Weighted Uni Frac distance,PCo A calculationResults Analysis of the phylum level composition of pregnant women’s vaginal flora:Before and after vaginal delivery and 42 days after delivery,the first four dominant phyla with the highest richness were Firmicutes,Actinobacteria,Proteobacteria and Bacteroidetes.From the period before delivery to the period after delivery to 42 days after delivery,the abundance of Firmicutes gradually decreased,while the abundance of Bacteroidetes gradually increased.(1)Compared with the vaginal flora before and after delivery,the abundance of Firmicutes decreased significantly,Proteobacteria increased significantly,and Bacteroidetes increased significantly,with statistically significant differences among the three,while the change of Actinobacteria showed no statistical significance;(2)Compared with the vaginal flora before delivery and 42 days after delivery,the abundance of Firmicutes decreased significantly,while the abundance of Bacteroidetes increased significantly,with statistically significant differences between the two,while the changes of Actinobacteria and Proteobacteria were not statistically significant;(3)Compared with the vaginal flora after delivery and 42 days after delivery,the abundance of Proteobacteria decreased significantly,and the abundance of Bacteroidetes increased significantly,with statistically significant differences between the two,while the change of Firmicutes and Actinobacteria showed no statistical significance。2.Analysis of the composition of the vaginal flora of pregnant women at the level of the genus: the vaginal flora before and after childbirth is dominated by Lactobacillus,and on the 42 th day postpartum is dominated by Anaerococuus.Before childbirth-after childbirth-42 days after childbirth,the abundance of Lactobacillus gradually decreased,the abundance of Apotobium,Gardnerella,Prevotella,Finegoldia and Peptoniphilus gradually increased;(1)Compared with before and after delivery,the abundance of Anaerococcus,Atopobium,Gardnerella,Prevotella,Finegoldia and Peptoniphilus increased,and the abundance of Gemella decreased significantly,with statistical significance for all the above bacteria,while the abundance of Rhodococcus and Lactobacillus no statistical significance;(2)compared to before delivery and postpartum 42 days,the abundance of Anaerococcus,Atopobium,Gardnerella,Prevotella,Finegoldia and Peptoniphilus increased,the abundance of Gemella,Rhdococcus and Lactobacillus decreased,with statistical significance for all the above bacteria;(3)Compared with before delivery and postpartum 42 days,the abundance of Anaerococcus,Prevotella,Finegoldia,Peptoniphilus was increased,and the abundance of Rhodococcus and Lactobacillus was decreased,and the above-mentioned bacteria were different Statistically significant;the abundance of Rhodococcus decreased,and the abundance of Atopobium and Gardnerella increased.and there was no statistical significance between the above bacteria.3.Analysis of α diversity of vaginal flora:Before delivery of the vaginal flora shannon index was significantly lower than after delivery,statistically significant differences,also significantly lower than that of postpartum 42 days,statistically significant difference,but after birth and postpartum42 days did not see obvious difference,shannon index shows that the maternal vaginal delivery,postpartum vaginal flora of alpha diversity increased,and this trend will keep to postpartum 42 days.4.Analysis of β-diversity of vaginal flora:The PCo A results showed that the three different periods of pregnant women’s flora were compared in pairs.Before and after childbirth,some samples overlapped,a small number of samples overlapped before and 42 days after childbirth,while a large number of samples were observed after childbirth and 42 days after childbirth.The group overlaps,indicating that vaginal delivery will lead to changes in part of the vaginal flora,and this change can last until 42 days postpartumConclusion Before and after delivery to 42 days postpartum,(1)The Lactobacillus in the vaginal flora of the parturient decreased gradually;(2)anaerobion(Anaerococcus,Atopobium,Gardnerella,Prevotella,Finegoldia and Peptoniphilus,etc.)gradually increased;(3)The alpha diversity and beta diversity of the flora increased;(4)More attention should be paid to the vaginal secretions of postpartum women in clinical practice.