title: Pathologic and molecular characterization of histomoniasis in peafowl ( Pavo cristatus).
abstract: Histomonas meleagridis is a flagellate protozoan organism that can cause severe necrotizing typhlitis and hepatitis in gallinaceous birds. Peafowl ( Pavo spp.) have been shown to be susceptible to histomoniasis in experimental settings, but there are few reports of natural histomoniasis in this species. A retrospective study of the archived cases at 2 veterinary diagnostic laboratories in the United States yielded 5 cases of peafowl with gross and histologic findings characteristic of histomoniasis. Lesions included bilateral, transmural fibrinonecrotic typhlitis and multifocal necrotizing hepatitis with associated trophozoites morphologically consistent with H. meleagridis. There was no evidence of Heterakis gallinarum infestation in the studied cases. DNA was extracted from formalin-fixed, paraffin-embedded liver and ceca from all 5 cases and was analyzed using multiple sets of primers with subsequent sequencing and genotyping. Four samples were positive for H. meleagridis, and 1 sample was positive for both H. meleagridis and Tetratrichomonas gallinarum. These results confirm that peafowl develop clinical disease similar to that described previously in other gallinaceous birds infected by H. meleagridis. The role of T. gallinarum remains unknown and further research is necessary to elucidate its role, if any, in the pathogenesis of the observed lesions.
authors.affiliation: Department of Pathology and Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine (Clarke, Rissi), University of Georgia, Athens, GA.|Department of Poultry Science, College of Agricultural and Environmental Sciences (Beckstead), University of Georgia, Athens, GA.|Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, Reynoldsburg, OH (Hayes).
authors.forename: Lorelei L
authors.initials: LL
authors.lastname: Clarke
authors.affiliation: Department of Pathology and Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine (Clarke, Rissi), University of Georgia, Athens, GA.|Department of Poultry Science, College of Agricultural and Environmental Sciences (Beckstead), University of Georgia, Athens, GA.|Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, Reynoldsburg, OH (Hayes).
authors.forename: Robert B
authors.initials: RB
authors.lastname: Beckstead
authors.affiliation: Department of Pathology and Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine (Clarke, Rissi), University of Georgia, Athens, GA.|Department of Poultry Science, College of Agricultural and Environmental Sciences (Beckstead), University of Georgia, Athens, GA.|Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, Reynoldsburg, OH (Hayes).
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Hayes
authors.affiliation: Department of Pathology and Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine (Clarke, Rissi), University of Georgia, Athens, GA.|Department of Poultry Science, College of Agricultural and Environmental Sciences (Beckstead), University of Georgia, Athens, GA.|Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, Reynoldsburg, OH (Hayes).
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Rissi
mesh_terms: D000818:Animals; D017931:DNA Primers; D003937:Diagnosis, Differential; D005260:Female; D005838:Genotype; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011200:Poultry; D011528:Protozoan Infections / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D011529:Protozoan Infections, Animal / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D016834:Trichomonadida / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D017931:DNA Primers
keywords: Histomonas meleagridis; peafowl; polymerase chain reaction