Author
 |
ONDRAK, JEFF - University Of Nebraska |
|
Cushman, Robert - Bob |
|
Submitted to: Abstracts World Buiatrics Congress
Publication Type: Abstract Only Publication Acceptance Date: 2/5/2016 Publication Date: 6/1/2016 Citation: Ondrak, J.D., Cushman, R.A. 2016. Prevalence of non-Tritrichomonas foetus trichomonads in preputial samples from Nebraska beef bulls. Proceedings of the 29th World Buiatrics Congress, July 3-8, 2016, Dublin, Ireland. 514. Interpretive Summary: Technical Abstract: Objectives Bovine trichomoniasis is a venereal disease of cattle found throughout the world caused by the single celled obligate parasite of the bovine reproductive tract Tritrichomonas foetus and is responsible for reproductive failure in females which leads to production loss and financial hardship for owners of infected herds. Females typically eliminate the organism from their reproductive tracts and return to normal fertility while males become chronic, unapparent carriers of the parasite. A key component of a trichomoniasis prevention or control program is the detection and removal of carrier bulls from the breeding population through culture and microscopic examination or polymerase chain reaction (PCR) testing of specimens collected from the preputial cavity of bulls. A disadvantage of culture based testing is the presence of non-T. foetus trichomonads which have a very similar appearance to T. foetus and may lead to falsely labelling bulls as infected. The use of PCR with T. foetus specific primers provides an alternative testing regime that is less susceptible to false positives due to non-T. foetus trichomonads; however, a lack of accessibility to and a higher cost for PCR testing may lead some individuals to continue to utilize culture based testing. Therefore, it is important to know how frequently non-T. foetus trichomonads are present in preputial specimens to allow diagnosticians to make informed interpretations of culture test results. The purpose of this study was to determine the prevalence of non-T. foetus trichomonads in the preputial samples from a herd of Nebraska beef bulls. Materials and methods Preputial specimens were collected from all bulls in a single herd with no history of trichomoniasis. The bulls were of various breeds and ranged in age from one to five years and were sexually rested for at least four months prior to sample collection using a previously described dry pipette technique. All samples were inoculated into a commercially available plastic pouch containing culture medium immediately after collection and maintained at room temperature until placed in an incubator within four hours of collection. Inoculated pouches were incubated upright at 37°C for four days. Pouches were systematically examined daily for the presence of trichomonads by an experienced veterinarian using light microscopy starting 24 hours after collection and continuing through the fourth day after collection. Pouches were classified as positive if live protozoa of a size, morphology, and motility pattern consistent with trichomonads were seen on at least one of the five days. After the microscopic examination on the fourth day all culture positive pouches were submitted for gel PCR testing using T. foetus specific and pan trichomonad primers according to the laboratory’s standard protocols. Commercially available software was used to calculate the prevalence and 95% confidence interval of non-T. foetus positive samples. Results Three hundred and fifty-two bulls from one to five years of age were sampled and produced three culture positive, T. foetus PCR negative, pan trichomonad PCR positive samples resulting in an overall non-T. foetus prevalence of 0.85% (95% CI, 0.29% to 2.48%). All three positive samples were from yearling bulls resulting in a non-T. foetus prevalence of 2.0% (95% CI, 0.68% to 5.71%) for this age group of 150 bulls. All 202 bulls two years of age and older were culture negative resulting in a non-T. foetus prevalence of 0.0% (95% CI, 0.0% to 1.87%) for this age group. Conclusions Non-T. foetus trichomonads in bull preputial samples were first reported in virgin, yearling bulls and were partially attributed to young bulls’ propensity for homosexual behavior making them more likely to harbor non-T. foetus trichomonads in their prepuce. The current study supports this assumption |
