Pathogenicity of a recently isolated strain of Tritrichomonas foetus in mice

The pathogenicity of a recently isolated strain of T. foetus in mice was studied. The parasite produced local abscesses 3 days post subcutaneous inoculation (p.i.) in albino mice. The abscesses in mice, inoculated with large numbers (4 × 10⁶) of organisms, continued increasing in size until the 14th day. Some absceses ruptured between day 11 to 14 p.i., while others formed a point. Secondary abscesses were also found in some mice. the abscesses in mice, inoculated with small numbers (1 × 10⁶) of organisms reached their maximum on the 5th day and decreased thereafter. All the abscesses had motile trichomonads with no bacterial contamination. The trichomonads, inoculated intraperitoneally in mice, persisted in that cavity till day 5 or 6 p.i., but did not multiply. Subcutaneous inoculations appear to be more reliable than the intraperitoneal ones for studies on pathogenicity. The comparison of present observations with those using a similar model and T. foetus or other trichomonads, suggests that the strain of T. foetus employed was of low pathogenicity.