Metronidazole for the treatment of Tritrichomonas foetus in bulls

Abstract

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.

Evaluation of the susceptibility of Tritrichomonas foetus to extracts of Lantana camara (Verbenaceae) by flow cytometry

“…Besides, the FDA currently prohibits its use in all food-producing animals. This institution has the authority to prohibit "the extralabel use of the drug or drug class presents a public health risk" in his case, due to its potential to cause cancer in humans (Love et al, 2017). As a consequence, there is currently no effective therapy for BT (Carvalho & Gadelha, 2007;Bader et al, 2016) and no vaccine has yet been developed to prevent the disease (Hairgrove et al, 2020).…”

“…Indiscriminate use of trichomonicidal drugs, under-dosage and lack of post-treatment controls have led to failures in therapeutic e cacy and chemoresistant strains (Campero CM, 2006). In addition, the FDA prohibits its application intended for food production (Love et al, 2017). Currently, there is no 100% effective treatment against BT (Carvalho & Gadelha, 2007), so it is usually decided not to treat sick bulls but send them to slaughter instead.…”

Molecular prevalence and phylogenetic confirmation of bovine trichomoniasis in aborted cows in Iraq

“…Although highly specific and sensitive diagnostic tools have been developed, success is restricted in field conditions [3]. Recently, a single polymerase chain reaction (PCR) test has been used for the regular examination of herds in developed countries, such as Australia, China, and United States of America (USA), which has a sensitivity of 78%-96.7% compared with cultures, and accurately identifies infected populations [7][8][9][10][11][12][13].…”

Insight into lanthanides REVO4 (RE = Ce, Pr, Nd): a comparative study on RE-site variants in the electrochemical detection of metronidazole in environmental samples

“…), the Ministry of Agriculture of the People's Republic of China, and the U.S. Food and Drug Administration (FDA) due to their extreme danger to both human and animal health as well as their propensity to aggregate in aqueous media. 5,6 IARC reported that MNZ causes animal cancer due to MNZ present in feed supplements. However, no data is yet available on MNZ inducing carcinogenicity in human beings.…”