Dynamics of Vaginal Bacterial Communities in Women Developing Bacterial Vaginosis, Candidiasis, or No Infection, Analyzed by PCR-Denaturing Gradient Gel Electrophoresis and Real-Time PCR

Abstract

The microbial flora of the vagina plays a major role in preventing genital infections, including bacterial vaginosis (BV) and candidiasis (CA). An integrated approach based on PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR was used to study the structure and dynamics of bacterial communities in vaginal fluids of healthy women and patients developing BV and CA. Universal eubacterial primers and Lactobacillus genus-specific primers, both targeted at 16S rRNA genes, were used in DGGE and real-time PCR analysis, respectively. The DGGE profiles revealed that the vaginal flora was dominated by Lactobacillus species under healthy conditions, whereas several potentially pathogenic bacteria were present in the flora of women with BV. Lactobacilli were the predominant bacterial population in the vagina for patients affected by CA, but changes in the composition of Lactobacillus species were observed. Real-time PCR analysis allowed the quantitative estimation of variations in lactobacilli associated with BV and CA diseases. A statistically significant decrease in the relative abundance of lactobacilli was found in vaginal fluids of patients with BV compared to the relative abundance of lactobacilli in the vaginal fluids of healthy women and patients with CA.

Effect of iron on the probiotic properties of the vaginal isolate Lactobacillus jensenii CECT 4306

“…Since the first microbiological study of the human vagina, lactobacilli have been considered the dominant members of the microbiota of this organ (Doderlein, 1982), a finding that has been further confirmed by several recent metagenomic studies (Biagi et al, 2009;Fettweis et al, 2012;Martín et al, 2014;Pavlova et al, 2002;Song et al, 1999;Verhelst et al, 2004;Vitali et al, 2007;Wilks et al, 2004;Zhou et al, 2004). In total, around 20 different species of lactobacilli have been consistently isolated from the vagina, although only one or two species predominate at a time in a given individual.…”

“…In total, around 20 different species of lactobacilli have been consistently isolated from the vagina, although only one or two species predominate at a time in a given individual. Dominant strains vary as a function of race and lifestyle, but strains of Lactobacillus crispatus, Lactobacillus iners, Lactobacillus jensenii and Lactobacillus gasseri are the most frequent (Biagi et al, 2009;Pavlova et al, 2002;Song et al, 1999;Verhelst et al, 2004;Vitali et al, 2007;Wilks et al, 2004;Zhou et al, 2004).…”

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“…Their sample size was very small though. Studies have shown that alteration of or abnormal vaginal bacterial flora predispose to RVVC only in the presence of antibiotic use [58,59]. It is worth noting thought that the majority of women who receive antibiotics do not develop genital candidiasis and majority of women with genital candidiasis have not used antibiotics in the immediate past.…”

Assessment of vaginal microbiota in Brazilian women with and without bacterial vaginosis and comparison with Nugent score

“…However, it is still unclear whether the primary event for BV onset is the loss of Lactobacillus species or the acquisition of complex microbial communities found in this syndrome, or both [5,9]. In this context, vaginal microbial structure characterization in BV and non-BV women is important to understand the complex etiology of this disease, especially considering the non-Gardnerella vaginalis species [1,12,13].…”

“…Microorganisms inhabiting the vaginal environment are constantly submitted to selective pressures, like immune response and pH, which contribute to ecosystem balance and modulate its distribution on resident microbiota [1]. Therefore, the health status of female genital tract is dependent on the vaginal bacterial community [2].…”