Prolonged resilience of Tritrichomonas foetus in cat faeces at ambient temperature

We have investigated the diagnostic utility of culture methods for Tritrichomonas foetus from cat faeces and the influence of faecal storage on the sensitivity of two different culture systems, InPouch TF-Feline (Bio-Med Diagnostics) and Modified Diamond's Medium. Normally formed cat faeces were spiked using a 10-fold serial dilution of 2 × 102 to 2 × 105T. foetus per gram of faeces prior to storage at either room temperature or under refrigeration. At different time points a 20 mg sample of spiked faeces was inoculated into each of the culture systems which were evaluated daily for up to 7 days and on day 11. Successfully cultured T. foetus 24 h following faecal spiking and storage at room temperature demonstrates that the environmental resilience of the organism is greater than previously anticipated. At a conservative detection limit of 2 × 103 organisms per gram of faeces the accumulative sensitivity of each culture method was found to be 83% and 100% for the InPouch TF-Feline and Modified Diamond's Medium respectively over a 6 h period. This research demonstrates that voided faeces kept at room temperature for up to 6 h represent suitable material for diagnostic investigation. The resilience of T. foetus suggests that transmission is not limited to close contact between cats.