Viability of Trichomonas vaginalis in vitro at four temperatures

The effect of temperature as a possible factor on the survival of Trichomonas vaginalis for shipment or routine laboratory maintenance was studied. Ten strains of T. vaginalis, ATCC 30001, ATCC 30238, and eight clinical isolates, were examined for viability when kept incubated at 37 degrees C or removed from this temperature and held at 42, 22, or 5 degrees C for increasing lengths of time without subculture or reincubation at 37 degrees C. The order in which the strains remained viable without subculture was: 5 degrees C, 8 to 10 days; 22 degrees C, 4 to 8 days; 37 degrees C, 4 to 6 days; 42 degrees C, less than 2 days. Vials of medium with cells were also held at 22 and 5 degrees C and then reincubated at 37 degrees C. Cultures held at 22 degrees C remained viable 6 to 8 days, whereas those stored at 5 degrees C remained viable 10 to 14 days. These data show that T. vaginalis withstands a wide range of temperatures, particularly below normal growth temperatures without subcultures, beyond what would be expected in mailing cultures.