Evaluation of the accessory sex glands of the bull for the presence of Tritrichomonas foetus

Abstract

A bull infected with the venereal protozoan Tritrichomonas foetus can become a chronic carrier, remaining infected for life. It has been theorized that as a bull ages he develops deep folds or crypts in the epithelium covering the penis and prepuce, creating an environment in which the parasite can establish long-term residence. No evidence-based reports have been found to support this assumption. Trichomonas vaginalis, the venereal protozoan of humans, will infect men and can establish a similar chronic carrier state following ascension of the urethra and infection of the prostate. This study was designed to determine if T. foetus could act similarly to T. vaginalis and ascend the urethra and infect the accessory sex glands of the bull. Twenty two bulls naturally infected with T. foetus were followed to an abattoir to harvest tissues from the full complement of accessory sex glands. Each gland was identified and two tissue samples from each gland were placed in Diamond’s media. One tissue sample remained in media and was observed daily according to routine T. foetus culture methods. Tissue cultures were observed over four days yielding no obvious parasite growth or motility. The second tissue sample from each organ was portioned and macerated to prepare for DNA extraction. PCR was performed using gel electrophoresis. A single prostate sample was identified as positive using this PCR protocol. Using comparative DNA sequencing, the positive sample was verified to be T. foetus. Although further research must be conducted to validate results from this study, it appears that T. foetus may behave similarly to T. vaginalis in ascension of the urogenital tract and invasion of the prostate of its male host.