ABSTRACT
The human cervicovaginal microbiota resides at an interface between the host and the environment and may affect susceptibility to disease. Puerto Rican women have high human papillomavirus (HPV) infection and cervical cancer rates. We hypothesized that the population structure of the cervicovaginal bacterial and fungal biota changed with cervical squamous intraepithelial lesions and HPV infections. DNA was extracted from cervix, introitus, and anal sites of 62 patients attending high-risk San Juan clinics. The 16S rRNA V4 region and ITS-2 fungal regions were amplified and sequenced using Illumina technology. HPV genotyping was determined by reverse hybridization with the HPV SPF10-LiPA25 kit. HPV prevalence was 84% of which â¼44% subjects were infected with high-risk HPV, â¼35% were co-infected with as many as 9 HPV types and â¼5% were infected with exclusively low-risk HPV types. HPV diversity did not change with cervical dysplasia. Cervical bacteria were more diverse in patients with CIN3 pre-cancerous lesions. We found enrichment of Atopobium vaginae and Gardnerella vaginalis in patients with CIN3 lesions. We found no significant bacterial biomarkers associated with HPV infections. Fungal diversity was significantly higher in cervical samples with high-risk HPV and introitus samples of patients with Atypical Squamous Cells of Undetermined Significance (ASCUS). Fungal biomarker signatures for vagina and cervix include Sporidiobolaceae and Sacharomyces for ASCUS, and Malassezia for high-risk HPV infections. Our combined data suggests that specific cervicovaginal bacterial and fungal populations are related to the host epithelial microenvironment, and could play roles in cervical dysplasia.
ABSTRACT
Rhinella marina is a toad native to South America that has been introduced in the Antilles, likely carrying high loads of microorganisms, potentially impacting local community diversity. The amphibian skin is involved in pathogen defense and its microbiota has been relatively well studied, however, research focusing on the cane toad microbiota is lacking. We hypothesize that the skin microbial communities will differ between toads inhabiting different geographical regions in Central America and the Caribbean. To test our hypothesis, we compared the microbiota of three populations of R. cf. marina toads, two from Costa Rican (native) and one Puerto Rican (exotic) locations. In Costa Rica, we collected 11 toads, 7 in Sarapiquí and 4 from Turrialba while in Puerto Rico, 10 animals were collected in Santa Ana. Separate swab samples were collected from the dorsal and ventral sites resulting in 42 samples. We found significant differences in the structure of the microbial communities between Puerto Rico and Costa Rica. We detected as much as 35 different phyla; however, communities were dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Alpha diversity and richness were significantly higher in toads from Puerto Rico and betadiversity revealed significant differences between the microbiota samples from the two countries. At the genus level, we found in Santa Ana, Puerto Rico, a high dominance of Kokuria, Niabella, and Rhodobacteraceae, while in Costa Rica we found Halomonas and Pseudomonas in Sarapiquí, and Acinetobacter and Citrobacter in Turrialba. This is the first report of Niabella associated with the amphibian skin. The core microbiome represented 128 Operational Taxonomic Units (OTUs) mainly from five genera shared among all samples, which may represent the symbiotic Rhinella's skin. These results provide insights into the habitat-induced microbial changes facing this amphibian species. The differences in the microbial diversity in Puerto Rican toads compared to those in Costa Rica provide additional evidence of the geographically induced patterns in the amphibian skin microbiome, and highlight the importance of discussing the microbial tradeoffs in the colonization of new ecosystems.
