Characteristics of the vaginal microbiomes in prepubertal girls with and without vulvovaginitis.

The present study focused on the characteristics of the vaginal microbiomes in prepubertal girls with and without vulvovaginitis. We collected 24 vaginal samples and 16 fecal samples from 10 girls aged 3-9 years with vulvovaginitis and 16 healthy girls of the same age. The samples were divided into three groups: fecal swabs from healthy controls (HF), vaginal swabs from healthy controls (HVS), and vaginal swabs from girls with vulvovaginitis (VVS). Sequencing of the V3-V4 region of the 16S rDNA gene was performed with the NovaSeq PE250 platform to reveal the vaginal microbial community structure in healthy prepubertal girls and vulvovaginitis-associated microbiota. The intestinal microbiomes of healthy children were also analyzed for comparison. This study revealed that the healthy vaginal tract in prepubertal girls was dominated by Prevotella, Porphyromonas, Ezakiella, and Peptoniphilus species, with a high diversity of microbiota. The vulvovaginitis-associated microbiota were dominated by Streptococcus, Prevotella, Haemophilus, and Granulicatella, with lower diversity than that in healthy girls. Furthermore, the compositions of the vaginal and intestinal microbiomes were completely different. ANOSIM, MRPP, Adonis, and AMOVA were used to analyze the beta diversity, and the results showed that there were significant differences in the microbial communities among the three groups. 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 vulvovaginitis-associated vaginal microbiota differed dramatically from normal microbiota, and the main causative agents were not fecal in origin.

Preparation and characterization of an attenuated porcine epidemic diarrhea virus strain by serial passaging.

Porcine epidemic diarrhea virus (PEDV) is prevalent in most parts of the world. Owing to its antigenic variation, prevention of the diseases caused by this virus is difficult. In this study, two PEDV isolates with similar growth kinetics were successfully propagated in Vero cells. Complete genome sequence analysis showed that they have a 49nt deletion in the ORF3 gene and were classified into Group 1, the same group that includes the classical CV777 strain. Recombination analysis revealed that the event had occurred in the ORF1a gene, at 3596-6819 nt, among the two PEDV isolates and the CV777 and DR13 strains. During their continuous propagation, 14 nonsynonymous mutations occurred in the spike (S) gene of strain JS-2/2014 between generations G5 and G90, but there were no changes between G90 and G100. We assumed that strain JS-2/2014 might be attenuated by the 90th generation. Piglets orally fed with JS-2/2014 G90 showed no clinical symptoms, and no virus was detected in the feces and nasal fluid. In conclusion, JS-2/2014 was successfully identified by screening, was attenuated after propagation in Vero cells, and may serve as a candidate virus for vaccine preparations.