Optimization of a species-specific polymerase chain reaction assay for identification of Pentatrichomonas hominis in canine fecal specimens

• Published in: American journal of veterinary research Vol. 68; no. 7; pp. 783 - 787
• Main Authors: Gookin, J.L, Stauffer, S.H, Coccaro, M.R, Marcotte, M.J, Levy, M.G
• Format: Journal Article
• Language: English
• Published: United States 01.07.2007
• Subjects: animal parasites and pests; Animals; detection limit; diagnostic techniques; diarrhea; Diarrhea - diagnosis; Diarrhea - parasitology; disease diagnosis; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; dog diseases; Dog Diseases - diagnosis; Dog Diseases - parasitology; Dogs; feces; Feces - parasitology; Female; Male; pathogen identification; pathogenicity; Pentatrichomonas hominis; pets; polymerase chain reaction; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - veterinary; protozoal infections; Protozoan Infections, Animal - diagnosis; Protozoan Infections, Animal - parasitology; ribosomal RNA; Species Specificity; Trichomonadida - genetics; Trichomonadida - isolation & purification
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.68.7.783

To determine the optimum reaction conditions and detection limits of PCR assay for identification of Pentatrichomonas hominis in DNA extracted from canine feces. DNA extracted from feces of 4 dogs with diarrhea from which trichomonads were observed, 81 dogs that had feces submitted to a diagnostic laboratory, and 19 dogs residing in a laboratory animal facility. Optimum reaction conditions and absolute and practical detection limits of 2 P hominis 18S species-specific primer pairs were determined by use of an in vitro cultivated canine isolate of P hominis in the presence and absence of canine feces. The optimized PCR assay was applied to amplification of P hominis 18S rRNA genes from DNA extracted from the feces of dogs. Under optimized conditions, a primer pair was identified as able to detect as few as 1 P hominis organism/180-mg fecal sample. The PCR assay identified P hominis in diarrheic feces of 4 dogs in which trichomonads were seen by light microscopy. The P hominis genes were not amplified from other fecal samples examined. Molecular identification of P hominis in feces of 4 dogs with trichomonosis and diarrhea reported here validates the identity of this species in such infections. Sensitive and specific PCR amplification of P hominis 18S rRNA genes from DNA extracted from feces will directly facilitate studies examining pathogenicity of this trichomonad and enable differentiation of P hominis from other known or novel species of trichomonads that may infect the gastrointestinal tract of dogs.