Vaginal microbiota evaluation and prevalence of key pathogens in ecuadorian women: an epidemiologic analysis

Abstract

Vaginal infection is a gynecological problem in women of reproductive age with multiple health outcomes. The most common forms of infection include bacterial vaginosis (BV), vulvovaginal candidiasis (VC), and aerobic vaginitis (AV). Our main goals were to evaluate different types of vaginal infections in Ecuadorian women in a large urban area (Quito) and to characterize the vaginal microbiota colonization by opportunistic species. We collected vaginal swabs and epidemiological surveys from 414 women from June 2016 to July of 2017. We analyzed vaginal samples for the presence of any vaginal infection. The microbiological examination was done through Gram-stain, wet mount smears, and polymerase chain reaction (PCR) assays using primers for target genes, such as 16S rRNA (Atopobium vaginae, Mobiluncus mulieris, and Gardnerella species), ddl (Enterococcus faecalis), adk (Escherichia coli) and KER1 (Candida albicans) genes. Most women showed a healthy vaginal microbiota (66.7%). Nearly one-tenth (10.4%) of the participants had intermediate microbiota, and the remaining women (22.9%) had a single vaginal infection (BV, AV, or VC) or coinfections. From the 95 participants that had an infection, AV was the main diagnosed vaginal infection (51.6%), followed by BV (24.2%) and finally VC (7.4%). The remaining women (16.8%) showed coinfections, being BV and AV the most common coinfection. Using univariable logistic regression analyses we found an increased odds of healthy microbiota in women with a sexual partner (P = 0.02, OR = 1.64). Also, women in a free union relationship (P = 0.000, OR = 16.65) had an increased odds of having coinfections. On the other hand, the use of birth control (condom OR = 0.388 or other contraceptive method OR = 0.363) was associated with significantly lower odds of intermediate microbiota (P ≤ 0.05). We found no statistically significant differences between women with infection and a particular group age. Using multivariate logistic regression analyses we initially found an increased odds of having BV in women with M. mulieris (P = 0.020, OR = 4.98) and Gardnerella species (P = 0.010, OR = 4.16). Women with E. coli showed an increased odds of having AV (P = 0.009, OR = 2.81). The presence of C. albicans in women showed an increased odds of having VC (P = 0.007, OR = 17.94). Finally, women with M. mulieris showed a reverse odds of having healthy microbiota (P = 0.008, OR = 0.06). We found no statistically significant differences between women with symptomatic and asymptomatic infections or the presence of Enterococcus faecalis. We found using logistic regression analyses that M. mulieris was the most prevalent opportunistic pathogen among women with vaginal infection. Further studies should evaluate the possibility to use M. mulieris as a potential key predictor for vaginal infections.

An overview of vaginal infections’ etiologies in south-eastern Gabon

“…However, there is a statistically signi cant association between BV and vaginal infections (p 0.0001). This observation con rms that when the vaginal ecosystem is disturbed, the vaginal epithelium is less protected and vaginal infections would set in (6). According to others studies, AV is more commonly associated with BV (3,4,18).…”

“…It is important to mention that the 69 participants had been simultaneously diagnosed with BV, AV, and VVC in the study. As reported by Salinas et al and many authors, several sexual partners could represent a risk factor (6). Further analysis would be done in the population set to identify the main key species commonly associated with each mixed infection.…”

“…Compared to the nding of the present study, a similar prevalence (51.0%) was reported for AV among examinees women with signs of vaginitis in Bosnia and Herzegovina (4). Recently, Salinas et al (2020) found among Ecuadorian women that had a vulvovaginitis infection AV as the main diagnosed vaginal infection (51.6%), followed by BV (24.2%) and nally VVC (7.4%) (6). A high AV prevalence has been postponed in China (65.49%) among sexually active patients who underwent routine gynecological examination (18).…”

“…The exclusion criteria were de ned as follows: (1) outpatients under the legal age and (2) outpatients with clinically apparent herpes simplex infection. These selected variables were based on the literature (4,6,7,(16)(17)(18)(19)(20).…”

“…Ethnicity and geographical location would in uence the prevalence of vaginal infections. Several authors reported different inventory of the situation about vaginal's pathobionts, namely in Asia, Europe, Africa, and Latin America (6)(7)(8). As for Sub-Saharan Africa, Kenyon et al (2013) reported a higher prevalence of BV than other parts (9).…”