Microbioma reprodutivo humano: atualização do viroma seminal e avaliação da eficiência de primers 16s na detecção do bacterioma endometrial

Abstract

The reproductive tract microbiome is pivotal for reproductive success; however, its characterization involves methodological and conceptual challenges. This two-part study aimed to analyze this microbiological landscape through an integrative review of the seminal virome and an experimental evaluation of the efficiency of generic 16S rRNA gene primers in detecting the endometrial bacteriome. In the first stage, the literature review on the seminal virome identified 81 studies published between May 2021 and October 2024, revealing the presence of 22 viruses in human semen. The most frequently identified were Monkeypox (MPXV), followed by HIV, HPV, SARS-CoV-2, and HBV. Geographic analysis demonstrated significant heterogeneity in the distribution of publications, with Europe (led by Italy) accounting for the majority of articles, highlighting the need for greater research investment in other regions. In the second stage, the experimental evaluation of generic 16S primers (recommended by the Illumina platform) on low-biomass endometrial samples indicated that, while efficient in high-biomass samples (such as cervical samples), they were not sensitive enough for endometrial bacteriome detection. Assays with endometrial samples resulted in low amplification and nonspecific bands across the DNA extraction methods used (column kit, precipitation/proteinase K, or phenol-chloroform-isoamyl alcohol). In conclusion, while the seminal virome possesses a growing body of literature, precise characterization of the endometrial bacteriome requires protocol optimization due to the sample's low microbial load. Experimental results suggest the need for more specific primers or alternative methodologies, such as shotgun metagenomic sequencing, to ensure the reproducibility and reliability of results in clinical practice and to advance the diagnosis of infertility-associated dysbiosis.