Variations in the carbohydrate expression pattern and in lesions of the uterine horns of BALB/c mice infected with different Tritrichomonas foetus isolates.

Bovine tritrichomonosis, a sexually transmitted disease caused by the protozoan Tritrichomonas foetus, is characterized by producing reproductive alterations in cattle. Carbohydrates on the surface of the uterine epithelium are involved in the process of adhesion and colonization of the protozoan. The murine model has proved to be an inexpensive, practical and representative alternative to study the lesions produced in the natural host. For this work, during the first stage, 6-8 week old female BALB/c mice were inoculated with 24 different T. foetus isolates in order to classify them according to their pathogenicity. Then, seven isolates were selected and processed with lectin histochemistry to determine if the differences in pathogenicity corresponded to the changes found in the uterine carbohydrate expression pattern. In this work, we demonstrate the differences in the expression of the carbohydrate pattern between infected and uninfected mice. In addition, within the group of infected mice, differences were found in the degree of pathogenicity of the isolates, thus evidencing their biological variability.

Lectin binding pattern in the uterus of pregnant mice infected with Tritrichomonas foetus.

Bovine genital tritrichomonosis is caused by the protozoon Tritrichomonas foetus and leads to embryonic death and abortion. The complexity of handling bovine experimental systems has led to the development of alternative models. The infection has been reproduced in pregnant BALB/c mice. In the pathogenesis of the disease, adhesion of the protozoon to host cell surface glycoproteins is important. Labelling with soya bean agglutinin (SBA) and peanut agglutinin (PNA) lectins increases in the luminal and glandular uterine epithelium of non-pregnant infected mice. The aim of the present study was to determine whether these changes also occur in pregnant infected BALB/c mice. Female BALB/c mice were inoculated intravaginally with T. foetus and, 15 ± 3 days post infection, were paired with males overnight. Infected and control mice were sacrificed 6, 8 and 10 days later. Samples of uterus were labelled with a panel of biotinylated lectins. Infected mice showed increased binding of PNA and SBA. There was also increased binding of concanavalin (Con-A) by luminal epithelium and Ricinus communis agglutinin (RCA-1) by glandular epithelium at day 6 post coitum. These changes may be due to the production of enzymes by T. foetus, which could act to enhance adhesion and colonization and thus favour infection.