The effects of perineal disinfection on infant’s oral microflora after transvaginal examination during delivery

Background Early life microflora is an important determinant of immune and metabolic development and may have lasting consequences. However, the mode of delivery and the effect of povidone iodine disinfection on neonatal oral microflora colonization are still unclear. The objective of the study was to understand the effects of the use of polyvidone iodine on infant’s oral microflora after transvaginal examination during delivery, provided data support for the establishment of neonatal oral microflora health. Methods A total of 20 cases of full-term neonatal delivered in October 2017 in Shenzhen Bao’an Maternity and Child Health Hospital through vaginal delivery. These neonates were randomly divided into two groups, the conventional disinfection group and the non-disinfection group. Simultaneously, 10 infants with elective cesarean section were taken as comparison. With Illumina MiSeq platform, 16S rRNA V3-V4 sequencing method was used to analyze bacterial DNA of oral secretions. Results At the phylum level, compared to the non-disinfection group, higher relative abundance of Bacteroidetes and Proteobacteria, and lower proportion of Firmicutes were observed in the cesarean section group and the disinfection group. As main composition of phylum Firmicutes, genus Lactobacillus presented extremely low in the cesarean section group and the disinfection group, whereas it was the absolute dominant bacteria in the non-disinfection group. Compared with the caesarean section group, only Lactobacillus increased in majority of the non-disinfection group. There was no increase in Lactobacillus in the disinfection group, but Prevotella, Escherichia-Shigella, Staphyloccus, and Klebsiella increased significantly. Through KEGG pathway analysis, we found that there were more harmful pathways such as staphylococcus aureus infection, viral myocarditis and sporulation in the disinfection group. Conclusions The mode of delivery affects the infant’s Lactobacillus obtained from the mother. Moreover, vulvar disinfection played an important part in the colonization of neonatal oral microbiota. And the impact of the first oral colonizers on infant health needs further follow-up investigations.