Study of the viability of Tritrichomonas foetus in bovine cervical fluid

RAMIREZ, MARÍA ROSANA; SERENO BRUNO, ESTEFANIA; OYHENART, JORGE.; PARADISO, FRANCO; MORERO, MARIANA; FUCHS,

Buenos Aires

Congreso; Reunion anual de sociedades de biociencias; 2020

SAIC

Bovine trichomonosis is a venereal disease caused by the protozoan Tritrichomonas foetus and is very common in countries where extensive husbandry and natural service are practiced. The presence of the parasite in the bull is asymptomatic and tends to become chronic in the adult animal. Infection in females occurs naturally during heat and usually manifests as failed services and repetition of heat. In pregnant females, the protozoan can reach the uterus and invade the embryo tissues. The multiplication of T. foetus must guarantee its persistence until a new estrus and the infection of the male. This work was carried out based on the assumption that, in the absence of epithelial cells, the vaginal cervical mucus (VCM) can support the growth of T. foetus and due to the lack of scientific work that addresses the ability of the protozoan to proliferate in host fluids. The aim was to demonstrate that T. foetus can be cultivated directly in the VCM of bovines in different stages of the oestrus. Cervical mucus was collected from 53 unsynchronized Aberdeen Angus heifers owned by EEA INTA ? Anguil. An 8 mm thick plastic cannula was introduced to the bottom of the vaginal sac, aspirating with a 10 mL syringe. Due to the viscosity of the mucus, 23 of the 53 samples were obtained by instilling 5 mL of sterile distilled water and repeating the aspiration until a larger volume was recovered (diluted). For the cultivation of T. foetus in VCM, 5x104 trophozoites were seeded in 100 µL of VCM and cultivated in an oven at 37 °C. The growth of the same cells in complete medium or in saline solution (150 mM NaCl2, pH 7.4) was used as positive and negative control, respectively. The counts were made after 22 hours culture using a Neubauer chamber and Trypan Blue dye as a contrast. Live and dead cells were counted. 10 µL of each VCM was placed before plating on a slide in a drop and allowed to dry at room temperature. Photographs were taken to observe the crystallization of each sample under a microscope using 10x magnification. The samples were stained with Giemsa and each preparation was photographed again at 10x and 40x magnification. The vaginal cervical mucus is sufficient to promote the growth of T. foetus. The protozoan showed positive growth during estrus. In contrast, no growth was observed in the right-hander. The results allow us to hypothesize that the protozoan in a natural infection must modify the environment to persist in the female reproductive tract throughout the entire estrous cycle.