Culture

The T. vaginalis culture is 100% specific and therefore considered a 'gold standard' for trichomoniasis diagnosis. Trichomonas culture is the most sensitive diagnostic procedure, but will miss up to 15% of infected cases (Lossick 1988). Detailed aspects of T. vaginalis cultivation were reviewed by Lindstead (1989). A number of different media have been studied. Two media commonly used for T. vaginalis cultures are the modified Diamond's medium (tryptose-yeast extract maltose medium, TYM)42 and the Feinberg-Whittington medium (Feinberg and Whittington 1957). The two media seem to be equally effective for the isolation of T. vaginalis (Krieger et al. 1988). Diamond's medium and modified Diamond's medium can detect 97 and 90% of isolates from vaginal secretions, respectively. A modified thioglycolate medium supplemented with yeast extract, horse serum, and antimicrobial agents was as reliable as the more expensive Diamond's medium according to one recent study (Poch et al. 1996). Disadvantages with trichomonas culturing include: sensitivity to modes of transport to the laboratory, incubation-time in the laboratory of 2-7 days, requiring at least three wet mount evaluations by technical staff, and relatively high costs.

Another culture method for T. vaginalis is the InPouchâ„¢ TV culture method (BioMed Diagnostics Inc., Santa Clara, USA). The pouch, which can be used for specimen transport and culture, can maintain trichomonad viability for periods from 41 to 131 days (Borchardt and Smith 1991). Specimens may be sent by regular mail to the laboratory and examined under the microscope after 24h incubation. The test has a sensitivity of four organisms per millilitre (Borchardt et al. 1992), but requires up to three days of incubation and microscopic evaluation.

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