Tritrichomonas foetus: prevalence study in naturally mating bulls in Switzerland.
Switzerland is officially free from bovine Tritrichomonas foetus. While bulls used for artificial insemination (AI) are routinely examined for this pathogen, bulls engaged in natural mating, as well as aborted fetuses, are only very sporadically investigated, indicating that the disease awareness for bovine tritrichomoniasis is low. Natural mating in cattle is becoming increasingly popular in Switzerland. Accordingly, a re-introduction/re-occurrence of T. foetus in cattle seems possible either via resurgence from a yet unknown bovine reservoir, or via importation of infected cattle. The low disease awareness for bovine tritrichomoniasis might favor an unnoticed re-establishment of T. foetus in the Swiss cattle population. The aim of our study was thus to search for the parasite, and if found, to assess the prevalence of bovine T. foetus in Switzerland. We included (1) bulls over two years of age used in natural mating and sent to slaughter, (2) bulls used for natural service in herds with or without fertility problems and (3) aborted fetuses. Furthermore, the routinely examined bulls used for AI (4) were included in this study. In total, 1362 preputial samples from bulls and 60 abomasal fluid samples of aborted fetuses were analyzed for the presence of T. foetus by both in vitro cultivation and molecular analyses. The parasite could not be detected in any of the samples, indicating that the maximal prevalence possibly missed was about 0.3% (95% confidence). Interestingly, in preputial samples of three bulls of category 1, apathogenic Tetratrichomonas sp. was identified, documenting a proof-of-principle for the methodology used in this study.
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Bernasconi
Herd Health Service, Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Bodmer
Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Doherr
Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
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Janett
Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Thomann
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Spycher
Swissgenetics, Hauptstrasse 61, 5243 Mülligen, Switzerland.
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Iten
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Hentrich
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Gottstein
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Müller
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland. Electronic address: caroline.frey@vetsuisse.unibe.ch.
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Frey
D000018:Abomasum / Q000469:parasitology; D037881:Aborted Fetus / Q000469:parasitology; D000818:Animals; D001947:Breeding; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D005766:Gastrointestinal Contents / Q000469:parasitology; D008297:Male; D010413:Penis / Q000469:parasitology; D015995:Prevalence; D011529:Protozoan Infections, Animal / Q000453:epidemiology*; D013557:Switzerland / Q000453:epidemiology; D016834:Trichomonadida / Q000235:genetics / Q000302:isolation & purification; D016835:Tritrichomonas foetus / Q000502:physiology*
Culture and PCR; Fertility problems; Natural mating bulls; Tetratrichomonas sp.; Tritrichomonas foetus