Optimal sampling and analysis methods for clinical diagnostics of vaginal microbiome

Next-generation sequencing-based microbiological analysis is a complex way to profile vaginal microbiome samples since each step affects the results gained. Methodologies for sample collection lack golden standards. We compared Puritan DNA/RNA swab (PS) and Copan FLOQ swab (CS) and provided consistent and reliable microbiome profiles analyzed by 16S rRNA gene sequencing. We collected two consecutive vaginal samples utilizing PS with room temperature storing and CS with instant freezing from 26 women. Variable region 4 of bacterial 16S rRNA gene was amplified with single PCR by custom-designed dual-indexed primers and sequenced with Illumina MiSeq system. Read quality control, operational taxonomic unit tables, and alpha and beta diversities analysis were performed, and community richness, diversity, and evenness were evaluated and compared between the two samplings and tests. Nineteen sample pairs produced detectable, intact DNA during the extraction protocol and/or further microbial profiles. Alpha bacterial diversity indices were independent on the collection protocol. No significant statistical differences were found in the measured beta diversity metrics between the collection methods. Of the women, 43% had Lactobacillus-dominated vaginal microbiome profile despite of collection method. Previously reported important vaginal microbiome phyla Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were present in the sample set although their relative abundances varied among individuals. PS and CS enable constant vaginal microbiota sampling. The PS method with no need for instant freezing is suitable for on-site collections at clinics. Furthermore, it seems to be possible to take two samples instead of one with constant microbiological results.

Helminth Microbiota Profiling Using Bacterial 16S rRNA Gene Amplicon Sequencing: From Sampling to Sequence Data Mining

Symbiont microbial communities play important roles in animal biology and are thus considered integral components of metazoan organisms, including parasitic worms (helminths). Nevertheless, the study of helminth microbiomes has thus far been largely overlooked, and symbiotic relationships between helminths and their microbiomes have been only investigated in selected parasitic worms. Over the past decade, advances in next-generation sequencing technologies, coupled with their increased affordability, have spurred investigations of helminth-associated microbial communities aiming at enhancing current understanding of their fundamental biology and physiology, as well as of host-microbe interactions. Using the blood fluke Schistosoma mansoni as a key example of parasitic worms with complex life cycles involving multiple hosts, in this chapter we (1) provide an overview of protocols for sample collection and (2) outline an example workflow to characterize worm-associated microbial communities using high-throughput sequencing technologies and bioinformatics analyses of large-scale sequence data.