Exploiting 16S rRNA-based metagenomics to reveal neglected microorganisms associated with infertility in breeding bulls in Spanish extensive herds

• Published in: Research in veterinary science Vol. 150; pp. 52 - 57
• Main Authors: Polo, Coral, Hernández, Marta, García-Seco, Teresa, Fernández, Víctor, Briones, Victor, Diez-Guerrier, Alberto, Abad, David, Rodríguez-Lázaro, David, Domínguez, Lucas, Pérez-Sancho, Marta
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05-12-2022; Elsevier Limited
• Subjects: 16S rRNA-based metagenomics; Animal production; Bacteria; Bioinformatics; Bovine infertility; Breeding bull; Cattle; Fertility; Fetuses; Genera; Health care; Infertility; Metagenomics; Microbiomes; Microorganisms; Mycoplasma spp; Neglected pathogens; Pathogens; Public health; Reproductive system; rRNA 16S; Species diversity; Taxonomy; Variance analysis; Veterinary medicine; Spain; 16S rRNA-based metagenomics; Mycoplasma spp; Neglected pathogens; Breeding bull; Bovine infertility
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/j.rvsc.2022.04.019

Bovine infectious infertility represents a problem due to the high impact on animal production and, in many cases, in public health. A lack of information on the characteristics of the bacterial population of the bovine reproductive system can hamper a comprehensive understanding of reproductive pathologies and the role that the microbiome could play. A metagenomic study based on the V3-V4 hypervariable region of the bacterial 16S rRNA gene was performed in 1029 preputial samples from bulls raised in an extensive regimen in Spain (944 from herds with low fertility rates -case group-, and 85 samples from reproductively healthy herds -control group-). The most representative phyla as well as the most 10 abundant bacterial families and their abundance did not show significant differences in both case and control groups. Similarly, the (alpha and beta) diversity of the bacterial populations was similar in both type of herds: the Shannon and Simpson indices show a high diversity of species, while the Bray-Curtis dissimilarity index did not show relevant differences in the bacterial communities. A deeper analysis of the operational taxonomic units showed the presence of one genera, Mycoplasma spp. significantly associated with fertility problems. Our study highlights the promising potential that the application of sequencing techniques (e.g. 16S rRNA-based metagenomics) possesses in examining bovine infertility, as they are able to reveal different pathogens that could go unnoticed using diagnostic approaches for only the main known pathogens.
•Bacterial population diversity is high in both infertile and healthy bull herds.•The abundance of bacterial taxa is similar in both infertile and healthy bull herds.•Mycoplasma spp. showed association with infertility-related herds.•Metagenomics is a promising diagnostic tool in infectious bull infertility.