Bacterial identification of the vaginal microbiota in Ecuadorian pregnant teenagers: an exploratory analysis
Authors: Salinas Ana María , Osorio Verónica Gabriela , Endara Pablo Francisco , Salazar Eduardo Ramiro , Vasco Gabriela Piedad , Vivero Sandra Guadalupe , Machado Antonio 
Published: February 2018

Background

Bacterial vaginosis (BV) is a microbial imbalance (i.e., dysbiosis) that can produce serious medical effects in women at childbearing age. Little is known, however, about the incidence of BV or vaginal microbiota dysbiosis in pregnant teenagers in low and middle-income countries such as Ecuador. The scope of this exploratory analysis was to study the relationship between epidemiologic and microbial risk factors. Among the microbiology risk factors this study investigated fiveLactobacillusspecies, two of them know in preview studies as microbiology risk factors for BV development (Lactobacillus acidophilusandLactobacillus iners), and the last three known for being associated with a healthy vaginal tract (Lactobacillus crispatus,Lactobacillus gasseriandLactobacillus jensenii). In addition, fastidious anaerobes known to be microbial risk factors for BV development in pregnant teenagers were searched as well, more exactly,Gardnerella vaginalis,Atopobium vaginaeandMobiluncus mulieris.

Methods

Ninety-five healthy adolescent pregnant women, visiting a secondary level hospital in Quito, Ecuador, were enrolled into the study in 2015. The enrolled patients were between 10 to 13 weeks of pregnancy. Four epidemiological risk factors were collected in a survey: age, civil status, sexual partners and condom use. Also, vaginal pH was measured as a health risk factor. DNA was extracted from endocervical and exocervical epithelia from all the patients’ samples. PCR analysis was performed in order to characterize the presence of the eight bacterial species known as risk factors for BV development, targeting three anaerobes and fiveLactobacillusspecies. Univariate and multivariate analysis were performed to identify associated factors for the presence of anaerobic species using logistic regression.

Results

The 95 vaginal microflora samples of these teenagers were analyzed. Two of the bacterial species known to cause BV:A. vaginae(100%) andG. vaginalis(93.7%) were found in high prevalence. Moreover, the most predominant bacterialLactobacillusspecies found in the pregnant teenagers’ vaginal tract wereL. crispatus(92.6%),L. iners(89.5%) andL. acidophilus(87.4%). In addition, the average vaginal pH measured in the study population was 5.2, and high pH was associated with the presence of the three-anaerobic species (p = 0.001). Finally,L. jensenii’s presence in the study decreased in 72% the occupation of the three anaerobes.

Discussion

This work identified a high pH as a risk factor for BV anaerobes’ presence in adolescent pregnant women. Moreover, this study identifiedL. crispatus, L. inersandL. acidophilusto be the most abundant species in our study population. From all fastidious anaerobes analyzed in this study,A. vaginaewas present in all pregnant teenagers. To conclude,L. jenseniicould be a potential healthy vaginal microbiota candidate in pregnant teenagers and should be further analyzed in future studies.