DIAGNOSIS OF TRlTRlCHOMONAS FOETUS INFECTION IN BULLS USING TWO SAMPLING METHODS AND A TRANSPORT MEDIUM* L. F. TEDESCO, F. ERRICO and L. P. DELBAGLIVI
Miguel C. Rubino Veterinary Research Centre, Casilla de Correo 177, Montevideo, Uruguay SUMMARY: Preputial exudates were collected from 3 bulls infected with Trifrichornonas foetus by scraping the mucosa with a specially designed instrument and by aspiration. For diagnostic purposes the scraping method was superior in direct microscopic examination but both methods were equally good when the samples were cultured within 2 hours of collection. The organism remained viable in a transport medium for 24, 48 and 72 hours showing a lineal decrease in viability with time which was more than 3 times greater in samples aspirated than in samples scraped. Introduction
Cultural recovery of Tritrichomonas foetus was advocated by Johnson (1966) as being more efficient than direct microscopic examination for the diagnosis of infection in bulls. The aspiration method of Bartlett et a1 (1947) for the collection of preputial secretions for cultural examination continues to be used (Clark et a1 1971) although Stuka and Katai (1969) claimed that their specially designed scraping instrument possessed advantages. The trichomonad population decreases rapidly in preputial secretions after collection (Bartlett 1949) and it was presumably for this reason that Clark et a1 (1971) cultured samples within 2 to 3 hours after collection. The purpose of the work now reported was to determine if the transport medium used by Clark et ai (1972) for Campyfobacter fetus would be equally suitable for T . foetus and to compare 2 methods for the collection of preputial secretions. Materials and Methods Three Holstein bulls, 3-to 6-years-old, were experimentally infected with the same field strain of T. foetus and were not allowed natural service. Using the techniques of Tedesco et al (1977) preputial secretions were collected weekly for 33 weeks alternating the scraping and aspiration methods: samples were transported to the laboratory as described by those workers and processed within 2 hours of collection.
Laboratory Procedures Samples in peptone water were allowed to sediment at bench temperature for 10 minutes. A drop taken from the superficial layer of the deposited material was examined microscopically, using 100 x magnification, for the presence of typical forms of T. foetus. One ml from the same layer was inoculated into 16 ml of semi-solid culture medium (Sutherland et a1 1953) in 27 ml screw capped bottles, incubated aerobically for 4 days at 37°C and examined for presence of T. foetus. Work supported by the United Nation’s Dekelopment Programme and the Food and Agriculture Organization.
322
Three absorbent cotton wool swabs were simultaneously submerged into the remaining peptone water exudate and then introduced individually into three 27 ml screw capped bottles filled with the transport medium described by Clark et al (1972). The transport medium and swabs were held at 4°C to 7°C for periods up to 72 hours. At 24,48 and 72 hours cultures were prepared by introducing the swabs into the semi-solid medium and incubated and examined as described above. The results Were examined using the Chi-square test with Yates correction applied. The h e a l s in Figure 1 were determined by the least squares method and the parameters of significance were analyzed by the t-test.
Results
More cells of T. foetus were demonstrated in samples collected by the scraping as compared with the aspiration method (p
Miguel C. Rubino Veterinary Research Centre, Casilla de Correo 177, Montevideo, Uruguay SUMMARY: Preputial exudates were collected from 3 bulls infected with Trifrichornonas foetus by scraping the mucosa with a specially designed instrument and by aspiration. For diagnostic purposes the scraping method was superior in direct microscopic examination but both methods were equally good when the samples were cultured within 2 hours of collection. The organism remained viable in a transport medium for 24, 48 and 72 hours showing a lineal decrease in viability with time which was more than 3 times greater in samples aspirated than in samples scraped. Introduction
Cultural recovery of Tritrichomonas foetus was advocated by Johnson (1966) as being more efficient than direct microscopic examination for the diagnosis of infection in bulls. The aspiration method of Bartlett et a1 (1947) for the collection of preputial secretions for cultural examination continues to be used (Clark et a1 1971) although Stuka and Katai (1969) claimed that their specially designed scraping instrument possessed advantages. The trichomonad population decreases rapidly in preputial secretions after collection (Bartlett 1949) and it was presumably for this reason that Clark et a1 (1971) cultured samples within 2 to 3 hours after collection. The purpose of the work now reported was to determine if the transport medium used by Clark et ai (1972) for Campyfobacter fetus would be equally suitable for T . foetus and to compare 2 methods for the collection of preputial secretions. Materials and Methods Three Holstein bulls, 3-to 6-years-old, were experimentally infected with the same field strain of T. foetus and were not allowed natural service. Using the techniques of Tedesco et al (1977) preputial secretions were collected weekly for 33 weeks alternating the scraping and aspiration methods: samples were transported to the laboratory as described by those workers and processed within 2 hours of collection.
Laboratory Procedures Samples in peptone water were allowed to sediment at bench temperature for 10 minutes. A drop taken from the superficial layer of the deposited material was examined microscopically, using 100 x magnification, for the presence of typical forms of T. foetus. One ml from the same layer was inoculated into 16 ml of semi-solid culture medium (Sutherland et a1 1953) in 27 ml screw capped bottles, incubated aerobically for 4 days at 37°C and examined for presence of T. foetus. Work supported by the United Nation’s Dekelopment Programme and the Food and Agriculture Organization.
322
Three absorbent cotton wool swabs were simultaneously submerged into the remaining peptone water exudate and then introduced individually into three 27 ml screw capped bottles filled with the transport medium described by Clark et al (1972). The transport medium and swabs were held at 4°C to 7°C for periods up to 72 hours. At 24,48 and 72 hours cultures were prepared by introducing the swabs into the semi-solid medium and incubated and examined as described above. The results Were examined using the Chi-square test with Yates correction applied. The h e a l s in Figure 1 were determined by the least squares method and the parameters of significance were analyzed by the t-test.
Results
More cells of T. foetus were demonstrated in samples collected by the scraping as compared with the aspiration method (p
