Diagnosis of Tritrichomonas foetus-infected bulls, an ultimate approach to eradicate bovine trichomoniasis in US cattle?

Yao, Chaoqun

doi:10.1099/jmm.0.047365-0

Cited by 58 publications

(69 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Bovine trichomoniasis is distributed worldwide, with cases reported in America, Asia, Australia, Europe and South Africa where natural bull service is a means of cattle breeding (Yao, 2013). T. foetus undergoes only the trophozoite stage and is mainly transmitted between bulls and cows/heifers by coitus.…”

Section: Introductionmentioning

confidence: 99%

Tritrichomonas foetus infections in female beef cattle with abortion in Wyoming, USA

Yao

2015

JMM Case Reports

Self Cite

View full text Add to dashboard Cite

Introduction: Bovine trichomoniasis has been endemic in the USA since its discovery in the 1930s. Testing of bulls used for reproduction is currently mandated in 26 states to control spread of the disease. Although individual head prevalence in Wyoming has decreased since 2000 when the state's regulation started, the herd prevalence remains steady and the disease continues to have a wide geographic distribution. One factor neglected in current regulations is the role of infected cows/heifers in transmission. The latter may harbour Tritrichomonas foetus, the causative organism, up to a few weeks post‐abortion/parturition. This capacity enables them to spread the disease in spite of extensive bull testing. Case presentation: The purpose of the present study was to determine the prevalence among Wyoming beef cattle of detectable T. foetus infection in cows/heifers with a history of abortion for which samples had been tested. This retrospective study included all submissions to the Wyoming State Veterinary Laboratory between 2000 and 2010. Cows/heifers with a history of abortion among Wyoming producers were tested for trichomoniasis. Overall prevalence was 9.7 %. Furthermore, 4.5 % of aborted foetuses were positive. Conclusion: Our data collectively demonstrates that a percentage of cows/heifers that recently experienced abortion are positive for T. foetus and may play an important role in maintaining endemicity of bovine trichomoniasis.

show abstract

Section: Introductionmentioning

confidence: 99%

Tritrichomonas foetus infections in female beef cattle with abortion in Wyoming, USA

Yao

2015

JMM Case Reports

Self Cite

View full text Add to dashboard Cite

show abstract

“…12 Using the pooling methodology outlined in the present study, a slight difference in sensitivity was observed between the 1/5 and 1/3 sample pools when compared to testing the samples individually. Utilizing the study laboratory's protocol, pooling at a 1/5 dilution produced better sensitivity than the average reported sensitivity (approximately 90%) for a single cultured smegma sample tested by microscopy 5,8,15 and was equivalent to the stated sensitivity of 95% or higher, 21 obtained by collecting and culturing 3 separate smegma samples with 7 days of sexual rest between collections. Compared to nPCR and sequencing results, 1/5 pools had a kappa value of 91% that was equivalent to individual sample testing in 3 of the 5 feeder laboratories.…”

Section: Discussionmentioning

confidence: 99%

“…5,8,15 Specificity may also be compromised given the ability of other protozoa with morphology similar to T. foetus to be present in the bull's prepuce. 6,9 To increase the sensitivity of culture to 95% or more, it was calculated that 3 successive cultures, at least 7 days apart were necessary, 21 thus making this diagnostic process slow and expensive. Alternatively, many diagnostic laboratories and state regulatory agencies have modified and adopted a quantitative polymerase chain reaction (qPCR) 13 method that offers a rapid, quantitative, and more accurate detection system when compared to the classical microscopy method.…”

Section: Introductionmentioning

confidence: 99%

Pooling of cultured samples and comparison of multistate laboratory workflows with the MagMAX sample preparation system and VetMAX quantitative polymerase chain reaction reagents for detection ofTritrichomonas foetus–colonized bulls

et al. 2013

View full text Add to dashboard Cite

The objectives of the current study were 1) to compare sample preparation workflows and quantitative real-time polymerase chain reaction assays (qPCR) as currently used in veterinary diagnostic laboratories with a study protocol utilizing commercially available reagents for individual Tritrichomonas foetus testing, 2) to assess the accuracy of pooling cultured smegma samples followed by extraction and qPCR testing as used in the study laboratory, and 3) to assess the specificity of the currently used primers and probes by sequencing all positive and presumptive positive samples identified in the study laboratory in an attempt to capture any nucleotide variability between T. foetus isolates and to rule out false-positive results possibly due to Simplicimonas moskowitzi. Eight hundred three cultured smegma samples were collected from different regions of the United States with the collaboration of 5 veterinary testing laboratories. The samples were processed individually by the respective laboratories, and then sent to the study laboratory and retested using the study protocol. Comparison testing showed an overall agreement of 95.89% between the veterinary testing laboratories and the study laboratory. One hundred seventy-six positive or presumptive positive samples plus 625 negative qPCR samples were combined and retested using a pooling protocol. Pools consisted of 1 positive sample and 4 negative samples (1/5). These pools were processed using the same study laboratory protocols, and 96% of the positive samples were detected in these pools. Nested PCR followed by sequencing confirmed 175 of the 178 samples classified as positive or presumptive positive in the study laboratory as containing T. foetus–specific DNA.

show abstract

“…Tritrichomonas foetus TF) is a sexually transmitted protozoon that causes reproductive failure so disruptive among cattle that virtually all US states west of the Mississippi River have initiated control programs [1]. Each of these control programs is based on the testing and exclusion of individual bulls.…”

Section: Introductionmentioning

confidence: 99%

Metronidazole for the treatment of Tritrichomonas foetus in bulls

et al. 2017

View full text Add to dashboard Cite

Background Tritrichomonas foetus is a sexually transmitted protozoon that causes reproductive failure, among cattle, so disruptive that many western US states have initiated control programs. Current control programs are based on the testing and exclusion of individual bulls. Unfortunately, these programs are utilizing screening tests that are lacking in sensitivity. Blanket treatment of all the exposed bulls and adequate sexual rest for the exposed cows could provide a more viable disease control option. The objectives of this study were twofold. The first objective was to demonstrate effectiveness for metronidazole treatment of a bull under ideal conditions and with an optimized treatment regime. This type of study with a single subject is often referred to as an n-of-1 or single subject clinical trial. The second objective of the current study was to review the scientific basis for the banning of metronidazole for use in Food Animals by the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA). Results Results from an antimicrobial assay indicated that metronidazole at a concentration of 0.5 μg/mL successfully eliminated in vitro protozoal growth of bovine Tritrichomonas foetus. The estimated effective intravenous dose was two treatments with 60 mg/kg metronidazole, 24 h apart. A bull that had tested positive for Tritrichomonas foetus culture at weekly intervals for 5 weeks prior to treatment was negative for Tritrichomonas foetus culture at weekly intervals for five consecutive weeks following this treatment regimen. An objective evaluation of the published evidence on the potential public health significance of using metronidazole to treat Tritrichomonas foetus in bulls provides encouragement for veterinarians and regulators to consider approaches that might lead to permitting the legal use of metronidazole in bulls. Conclusion The study demonstrated successful inhibition of Tritrichomonas foetus both in vitro and in vivo with metronidazole. The current status of metronidazole is that the Animal Medicinal Drug Use Clarification Act of 1994 prohibits its extra-label use in food-producing animals. Veterinarians and regulators should consider approaches that might lead to permitting the legal use of metronidazole in bulls.

show abstract

Diagnosis of Tritrichomonas foetus-infected bulls, an ultimate approach to eradicate bovine trichomoniasis in US cattle?

Cited by 58 publications

References 47 publications

Tritrichomonas foetus infections in female beef cattle with abortion in Wyoming, USA

Tritrichomonas foetus infections in female beef cattle with abortion in Wyoming, USA

Pooling of cultured samples and comparison of multistate laboratory workflows with the MagMAX sample preparation system and VetMAX quantitative polymerase chain reaction reagents for detection ofTritrichomonas foetus–colonized bulls

Metronidazole for the treatment of Tritrichomonas foetus in bulls

Contact Info

Product

Resources

About