Different and less diverse microbiota

Vaginal microbiota in prepubescent girls with vulvovaginitis consists of different and less diverse flora than prepubescent girls without vulvovaginitis, according to a study published in the European Journal of Clinical Microbiology & Infectious Diseases.

Wu Xiaoming, MD, of the Department of Pediatric Gynecology at Beijing Children’s Hospital at Capital Medical University’s National Center for Children’s Health in China, and colleagues conducted the study. They noted that vulvovaginitis causes significant anxiety in children and their parents and that it is the most common gynecological disease in prepubescent girls.¹ Vulvovaginitis causes inflammation of the vulva and vagina.

The authors said that behavioral issues, in addition to anatomic and physiological factors for girls this age, can cause changes in vaginal microbiota. “Disorders involving vaginal flora usually cause infectious clinical syndromes with irritating symptoms, such as vaginal discharge, external genital organ erythema, soreness, itch, irritation, dysuria, and bleeding,” the authors noted.¹

Researchers collected samples from 10 girls with vulvovaginitis and 16 healthy girls aged 3 to 9 years. They examined 24 vaginal samples and 16 fecal samples collected between February 2020 and April 2020 at the National Center for Children’s Health in Beijing. Girls in the study did not have secondary sexual characteristics. Patients excluded from the study included those with a history of sexual abuse and those with other vaginal infections.

One trained pediatric gynecologist collected all the samples with a sterile swab and put the samples on dry ice and into a − 80 °C freezer within 30 minutes. No additives were used until the samples were analyzed.

Researchers collected samples from 10 girls with vulvovaginitis and 16 healthy girls aged 3 to 9 years.

Researchers categorized the samples into 3 groups: healthy fecal swabs (HF), healthy vaginal swabs (HV), and vulvovaginitis swabs (VVS). Researchers used the NovaSeq 6000 SP500 platform to determine vaginal microbiota by sequencing the V3-V4 region of the 16S rRNA gene.1 The authors also analyzed intestinal microbiota of healthy girls to compare results.

Prevotella, Porphyromonas, Ezakiella, and Peptoniphilus were prevalent in healthy girls. Healthy girls also had more vaginal microbiota diversity. “The dominant taxa in the HF group were Bacteroides, Faecalibacterium, Blautia, and Bifidobacterium, which were not the main vaginal bacteria in children with vulvovaginitis,” the authors said.

Girls with vulvovaginitis had lower vaginal microbiota diversity, with Prevotella, Porphyromonas, Ezakiella, Peptoniphilus, Campylobacter, Anaerococcus, Dialister, Haemophilus, and Granulicatella prevalent. “Compared with the HVS group, some of the top 30 bacteria (Granulicatella, Streptococcus, Gardnerella, Haemophilus, Atopobium) were enriched (P<0.05), while others (Prevotella, Porphyromonas, Ezakiella, Peptoniphilus, Campylobacter) were depleted in the VVS group (P < 0.05),” researchers reported.¹

“Lactobacillus deficiency and high bacterial diversity were characteristics of the vaginal microbiome in healthy prepubertal girls; this is inconsistent with that in reproductive-age women,” the authors wrote, noting that the differences in microbiota were not fecal in origin.¹ The study adds evidence that vulvovaginitis is caused by a disturbance in the vaginal microbiome. Because this microbiome has not been well defined in prepubescent girls, the purpose of this study was to document microbiota.

“Measures of alpha diversity indicated that the diversity of the vaginal microbiome in healthy prepubertal girls was high; vulvovaginitis-associated dysbiosis is generally characterized by loss of diversity and the presence of pathogens with high levels of abundance,” Xiaoming and colleagues concluded.

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Reference

Xiaoming W, Jing L, Yuchen P, Huili L, Miao Z, Jing S. Characteristics of the vaginal microbiomes in prepubertal girls with and without vulvovaginitis. Eur J Clin Microbiol Infect Dis. Published online January 16, 2021. doi:10.1007/s10096-021-04152-2