Not gone but forgotten: Tritrichomonas foetus in extensively-managed bulls from Australia's Northern Territory

Nichola Eliza Davies Calvani; Jan Šlapeta; Emily Onizawa; Kieran Eamens; Cheryl Jenkins; Mark Edward Westman

doi:10.1016/j.crpvbd.2021.100012

Not gone but forgotten: Tritrichomonas foetus in extensively-managed bulls from Australia's Northern Territory

Curr Res Parasitol Vector Borne Dis. 2021 Feb 2:1:100012. doi: 10.1016/j.crpvbd.2021.100012. eCollection 2021.

Authors

Nichola Eliza Davies Calvani^{1

2}, Jan Šlapeta², Emily Onizawa¹, Kieran Eamens¹, Cheryl Jenkins¹, Mark Edward Westman¹

Affiliations

¹ Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries and Environment, Menangle 2565, NSW, Australia.
² Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camperdown 2006, NSW, Australia.

Abstract

Bovine trichomonosis, caused by infection with the protozoan parasite Tritrichomonas foetus, is globally recognised as a cause of reproductive failure in cattle. Maintained in clinically normal bulls, T. foetus infection results in infertility and abortion in infected cows. In Australia's Northern Territory (NT), logistical limitations associated with extensive livestock production inhibit wide-scale testing and diagnosis, allowing the parasite to persist undetected. In the present study, T. foetus was detected in 18/109 preputial cultures collected from bulls on a property in the NT with a history of low birth rates and reproductive failure using real-time PCR testing. Of the T. foetus-positive samples, 13/18 were genotyped using the internal transcribed spacer regions (ITS1 and ITS2) and the 5.8S rDNA unit. Selected samples were further characterised using the protein-coding genes of cysteine proteases (CP-1, 2, 4-9) and cytosolic malate dehydrogenase 1 (MDH-1) to determine if the isolates were 'bovine', 'feline' or 'Southern Africa' genotypes. All samples were 100% identical to the T. foetus 'bovine' genotype across all markers. This is the first reported case of trichomonosis in Australian cattle since 1988 and is a reminder that T. foetus should be considered whenever reproductive failure occurs in extensive cattle systems.

Keywords: Bovine trichomonosis; Culture; Diagnosis; Infertility; Internal transcribed spacer regions; Molecular characterisation; Real-time PCR; Smegma samples; Veterinary science.