Detection of Tritrichomonas Foetus by Polymerase Chain Reaction in Cultured Isolates, Cervicovaginal Mucus, and Formalin-Fixed Tissues from iNfected Heifers and Fetuses

• Published in: Journal of veterinary diagnostic investigation 2003-11, Vol.15 (6), p.579-584
• Main Authors: BonDurant, Robert H, Campero, Carlos M, Anderson, Mark L, Van Hoosear, Karen A
• Format: Article
• Language: English
• Subjects: Abortion, Veterinary - microbiology; Animals; Biological and medical sciences; Cattle; Cattle Diseases - diagnosis; Cattle Diseases - microbiology; Cervix Mucus - microbiology; clinical trials; digestive system; Disease Outbreaks - veterinary; Female; Fixatives; Formaldehyde; Fundamental and applied biological sciences. Psychology; genome; heifers; internal transcribed spacers; Microbiology; mucus; pathogens; pigeons; polymerase chain reaction; Polymerase Chain Reaction - veterinary; Pregnancy; Protozoan Infections - diagnosis; Protozoan Infections, Animal; ribosomal RNA; screening; Sensitivity and Specificity; Specimen Handling; surveys; Tissue Fixation - veterinary; transcription (genetics); Trichomonas gallinae; Trichomonas vaginalis; trichomoniasis; Tritrichomonas foetus; Tritrichomonas foetus - genetics; Tritrichomonas foetus - pathogenicity
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063870301500613

A rapid, reliable polymerase chain reaction (PCR) assay, originally developed for definitive laboratory identification of the bovine venereal pathogen Tritrichomonas foetus from cultures of male reproductive tract fluids, was used for testing the following: 1) cultured, geographically disparate trichomonad isolates, 2) formalin-fixed tissues from infected heifers and naturally infected fetuses, and 3) cervicovaginal mucus (CVM) from experimentally infected females. In 12 of 12 Western Hemisphere isolates of pathogenic T. foetus (isolated from outbreaks of clinical trichomoniasis or from screening surveys) and in 1 of 1 American Type Culture Collection strain of Tritrichomonas suis, PCR yielded a positive result, i.e., a 347-base pair amplicon in the 5.8S ribosomal RNA and internal transcribed spacer (5.8S-ITS) region of the genome, whereas cultures of Trichomonas vaginalis and Trichomonas gallinae did not produce a PCR product. The PCR assay was also positive in formalin-fixed, paraffin-embedded endometrial samples from 4 of 4 experimentally infected heifers, as well as in archived tissues from 2 of 2 T. foetus-infected aborted bovine fetuses that were submitted to the diagnostic laboratory from a natural outbreak. It was negative in fixed, embedded uterine tissues of 2 of 2 uninfected virgin heifers used as negative controls and in archived fixed gut tissue of a T. gallinae-infected pigeon. In another experiment, CVM aspirated from 4 of 4 experimentally infected heifers in the fifth or sixth postinfection week yielded a positive PCR product of the expected size, whereas CVM from 2 of 2 controls were PCR negative. Pending validation in larger clinical studies, the PCR assay for the 5.8S-ITS coding region of the T. foetus genome offers the prospect of definitive identification of this agent directly from CVM or from formalin-fixed tissues or when false-positive culture results are suspected.