Changes in the predominant human Lactobacillus flora during in vitro fertilisation

Tell Jakobsson,Urban Forsum

doi:10.1186/1476-0711-7-14

Tell Jakobsson, Urban Forsum

Open Access

https://doi.org/10.1186/1476-0711-7-14

Copy DOI

Abstract

BackgroundSignature matching of nucleotide sequences in the V1 and V3 regions 16S rRNA genes using pyrosequencing technology is a powerful tool for typing vaginal Lactobacilli to the species level and has been used for investigating the vaginal microbial niche.MethodsThis study has characterized the normal cultivable vaginal Lactobacillus flora at varying estradiol levels in plasma; the study comprised 17 patients undergoing ovarian stimulation for In Vitro Fertilization (IVF) treatment. The vaginal status of each participant was initially assessed as normal according to Amsel and Nugent criteria.ResultsL. crispatus, L. gasseri and/or L. jensenii were present in 10 of the patients throughout the study period, and little variation among these three species was encountered in individual patients. The flora of three women was dominated by L. delbrüeckii, L. rhamnosus or L. vaginalis. One woman exhibited a dominance of L. iners. The flora of the remaining three women were initially dominated by L. rhamnosus or L. reuteri, but as their estrogen levels rose, their flora composition altered, to become dominated by one of the three species most common in a normal, healthy vagina.ConclusionSignature matching of nucleotide sequences in the V1 and V3 regions of 16S rRNA genes is a discriminative tool for the study of vaginal Lactobacilli and can be used to track the Lactobacillus flora under a variety of physiological conditions.

Highlights

Signature matching of nucleotide sequences in the V1 and V3 regions 16S rRNA genes using pyrosequencing technology is a powerful tool for typing vaginal Lactobacilli to the species level and has been used for investigating the vaginal microbial niche
A prevailing assumption is that the dominating normal vaginal flora comprises the genus Lactobacillus known as the L. acidophilus complex
Using a similar approach and definitions according to Amsel and Nugent criteria, this study aims at further characterizing the normal cultivable vaginal flora present at differing estradiol levels in plasma during ovarian stimulation for In Vitro Fertilization (IVF) treatment

Summary

Introduction

Signature matching of nucleotide sequences in the V1 and V3 regions 16S rRNA genes using pyrosequencing technology is a powerful tool for typing vaginal Lactobacilli to the species level and has been used for investigating the vaginal microbial niche. An altered cultivable flora arises when the number of lactobacilli in the vaginal fluid drastically decreases, and opportunistic bacteria, normally present in minute proportions, overgrow the vaginal epithelium. This leads to a rising pH (>4,7) which is conducive to the growth of anaerobes [1]. A prevailing assumption is that the dominating normal vaginal flora comprises the genus Lactobacillus known as the L. acidophilus complex. This assumption is based on earlier literature describing studies using phenotypic methods for typing bacteria and a line of reasoning (page number not for citation purposes)

Objectives

Methods

Results