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Use of a commercially available culture system for diagnosis of Tritrichomonas foetus infection in cats

Jody L. Gookin DVM, PhD, DACVIM1, Derek M. Foster BS2, Matthew F. Poore BS3, Marty E. Stebbins DVM, PhD, DACVPM4, and Michael G. Levy PhD5
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  • 1 Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.
  • | 2 Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.
  • | 3 Department of Food Animal and Health Resource Management, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.
  • | 4 Department of Food Animal and Health Resource Management, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.
  • | 5 Department of Food Animal and Health Resource Management, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.

Abstract

Objective—To evaluate the efficacy of and optimize a commercially available culture system for sensitive and specific in-clinic culture of Tritrichomonas foetus from cat feces.

Design—Prospective study.

Sample Population—Samples of freshly voided feces from 117 purebred cats and pure cultures of T foetus obtained from a cat with chronic diarrhea.

Procedure—Optimal conditions for use of the culture system, such as quantity of fecal inoculum (0.025 to 0.2 g) and cultivation temperature (25 or 37°C [98.6 or 77.0°F]), were determined. Specificity of the system was examined by attempted culture of Giardia lamblia and Pentatrichomonas hominis. Sensitivity of the system to detect T foetus was determined by inoculation of culture system pouches with serially diluted T foetus suspensions with and without feces.

Results—Detection limit of the culture system was 1 and 1,000 T foetus organisms without and with feces from cats, respectively. Optimal fecal inoculum was < 0.1 g of feces. At 37°C, cultures yielded positive results in 24 hours; organisms remained viable for 1 to 6 days, and bacterial overgrowth was common. At 25°C, cultures yielded positive results in 1 to 11 days; organisms were long-lived, and bacterial overgrowth was uncommon. Neither G lamblia or P hominis survived in the culture system.

Conclusions and Clinical Relevance—The culture system was sensitive and specific for culture of T foetus in feces of cats. Performance was optimal when test kits were inoculated with ≤ 0.1 g of freshly voided feces and cultured at 25°C. (J Am Vet Med Assoc 2003;222:1376–1379)

Abstract

Objective—To evaluate the efficacy of and optimize a commercially available culture system for sensitive and specific in-clinic culture of Tritrichomonas foetus from cat feces.

Design—Prospective study.

Sample Population—Samples of freshly voided feces from 117 purebred cats and pure cultures of T foetus obtained from a cat with chronic diarrhea.

Procedure—Optimal conditions for use of the culture system, such as quantity of fecal inoculum (0.025 to 0.2 g) and cultivation temperature (25 or 37°C [98.6 or 77.0°F]), were determined. Specificity of the system was examined by attempted culture of Giardia lamblia and Pentatrichomonas hominis. Sensitivity of the system to detect T foetus was determined by inoculation of culture system pouches with serially diluted T foetus suspensions with and without feces.

Results—Detection limit of the culture system was 1 and 1,000 T foetus organisms without and with feces from cats, respectively. Optimal fecal inoculum was < 0.1 g of feces. At 37°C, cultures yielded positive results in 24 hours; organisms remained viable for 1 to 6 days, and bacterial overgrowth was common. At 25°C, cultures yielded positive results in 1 to 11 days; organisms were long-lived, and bacterial overgrowth was uncommon. Neither G lamblia or P hominis survived in the culture system.

Conclusions and Clinical Relevance—The culture system was sensitive and specific for culture of T foetus in feces of cats. Performance was optimal when test kits were inoculated with ≤ 0.1 g of freshly voided feces and cultured at 25°C. (J Am Vet Med Assoc 2003;222:1376–1379)