La. Bryan et al., Effects of temperature on the survival of Tritrichomonas foetus in transport, diamond's and InPouch TF media, VET REC, 144(9), 1999, pp. 227-232
The abilities of two isolates of Tritrichomonas foetus to survive and repli
cate in transport and Diamond's medium or in the InPouch TF system (Bio-Med
Diagnostics) when exposed to different temperatures for different periods
were determined in a series of experiments. Tubes containing thioglycollate
transport medium or pouches were inoculated with 4000 to 5000 organisms an
d kept for up to seven days at 37 degrees C, 22 degrees C, 4 degrees C, or
-20 degrees C. When the holding time had elapsed, the numbers of motile T f
oetus were counted. Samples in transport medium were transferred to Diamond
's medium, and both the pouches and tubes containing Diamond's medium were
incubated at 37 degrees C. The cultures were examined and counted four or f
ive times during the 10 to 14 day culture period. The sensitivity of the te
st under the different conditions, expressed as the number of positive cult
ures/the total number of samples x 100, varied from zero to 100 per cent de
pending upon the combination of variables considered. In each medium, with
both isolates of T foetus, all samples kept for up to four days at 22 degre
es C or 37 degrees C were positive. All cultures of samples kept more than
five days at 4 degrees C were negative. No positive cultures were detected
when samples were kept more than three hours at -20 degrees C. The day on w
hich the cultures reached mean peak concentration varied with the temperatu
re at which the samples had been kept before they were cultured.