Abstract

Trichomoniasis, a venereal disease of cattle caused by the protozoan, Tritrichomonas foetus, (T. foetus) is characterized by pyometra and early to midgestation fetal abortion. Cows generally become clear of infection after 3 estrous cycles, but bulls remain the primary, long term, asymptomatic carrier for transmission of the disease agent. Currently there are no drugs available to treat infection and current vaccination strategies have provided limited to no protection in bulls and low efficacy in cows. Initial observations indicated that wild type E. coli exerted a toxic effect on the motility of T. foetus. Isolation and characterization of 3 wild type Escherichia coli (WT1, WT2, and WT3) cultured from contaminated preputial samples were evaluated for their ability to inhibit motility and/or reproduction of T. foetus in culture, with K12 as a control. Aerobic and anaerobic growth evaluation for bacterial toxicity did not reveal significant differences between E. coli isolates. Removal of ascorbic acid, cysteine, serum or yeast from the Diamond's Medium composition decreased the concentration of T. foetus in the presence of WT 2 E. coli. Enhanced trichomonal reproduction and motility were observed when bacterial isolate WT2 was cultured in Nutrient broth, Tryptose Broth, or Trypticase Soy Broth either with or without serum. All experiments were done with Phosphate Buffered Saline as a control, which unexpectedly, provided statistically enhanced growth and motility of T. foetus. While the hypothesis that wild type bacteria can inhibit the motility and concentration of T. foetus was not supported, unexpected enhancement of growth of T. foetus in the presence of various media and PBS suggest that further evaluation of culture media for trichomonal diagnosis may be warranted.