Describing the Reproductive Microbiome of Tritrichomonas foetus Chronically Infected Bulls and Diagnostic Collection Device Performance

<i>Tritrichomonas foetus (T. foetus)</i>, the causative agent of bovine trichomoniasis, is an obligate protozoan parasite of the bovine reproductive tract and can be found on the penis, prepuce, and distal urethra of the bull and from the cranial vagina to the oviduct in the infected cow. To date, the microbiome of bulls infected with <i>T. foetus</i> has not been described. The objectives of this study were to (1) describe the preputial and penile microbiome of bulls chronically infected by <i>T. foetus,</i> (2) describe the seminal microbiome of <i>T. foetus</i>-infected bulls, and (3) evaluate different collection devices that could be used for sampling. Eleven bulls naturally infected with <i>T. foetus</i> were utilized for the collection of samples. Samples were obtained during the process of a routine breeding soundness exam utilizing either a dacron swab, pizzle stick, double-guarded swab, or semen collection. The preputial and seminal microbiome of <i>T. foetus</i>-infected bulls was dominated by bacterial members of the phyla <i>Fusobacteriota, Firmicutes</i>, <i>Bacteroidota, Actinobacteria,</i> and <i>Campylobacterota.</i> Semen collection yielded the most microbial diversity; however, there was no significant difference between the four methods (<i>p</i> ≥ 0.05). This study characterizes both the preputial and seminal microbial communities of bulls chronically infected by <i>T. foetus.</i>