Occurrence of Tetratrichomonas gallinarum (Trichomonadida: Trichomonadidae) in chicken feces from Lorestan Province, Western Iran

A Cross-Sectional Survey of Gastrointestinal Parasites in an Ornithological Garden

Captive birds in collections may be infested with a wide range of parasites. Globally, information on parasitic infections and their health implications in ornithological collections are scarce. In the present study, the prevalence of parasitic infections in an ornithological garden in Tehran was investigated. Samples (n = 109) from various bird species were collected. Direct wet smear, sedimentation, flotation with Sheather's sugar, and modified Ziehl-Neelsen and Giemsa staining were used for parasite screening. Parasites were identified in 57 (52.3%, 95% confidence interval [CI] 42.9-61.7) samples, with protozoans being the most frequently observed organisms, including Cryptosporidium species, Eimeria species, Isospora species, Trichomonas species, and Histomonas species. Helminths were observed in 29 (26.6%, 95% CI 18.3-34.9) of the samples and included strongyles, Capillaria species, and Raillietina species. Ectoparasites were rarely recovered, but 2 species were identified: the poultry shaft louse (Menopon gallinae) and the fowl tick (Argas persicus). Free-ranging birds were significantly (P < 0.001) more likely to have parasites in their feces than caged birds. Fecal parasitic infections were order dependent and more prevalent in the Anseriformes and Galliformes (P < 0.05). The frequency of gastrointestinal parasites was notable in the investigated collection. In open natural bird gardens, such as in the present study, the probable transmission routes and sources of the parasitic infections are most likely via the free-ranging avian species. It is wise to recommend regular screening of the birds in these gardens to improve preventive control measures. Additionally, parasite genotyping should be considered to clarify our understanding of the epidemiology of zoonotic and nonzoonotic parasites.

Molecular prevalence of Tetratrichomonas gallinarum and Trichomonas gallinae in three domestic free-range poultry breeds in Anhui Province, China

Tetratrichomonas gallinarum and Trichomonas gallinae can colonize the alimentary tract of domestic birds. However, little information is available on the epidemiology of the two trichomonad species in domestic free-range poultry in China. In this study, the occurrence and genetic characteristic of T. gallinarum and T. gallinae among free-range chickens, ducks, and geese in Anhui Province, China, were investigated. The 1910 fecal samples collected from 18 free-range poultry farms throughout Anhui Province were examined for the presence of T. gallinarum and T. gallinae by PCR and sequence analysis of the small subunit (SSU) rRNA gene of T. gallinarum and ITS1-5.8S-ITS2 sequence of T. gallinae. The overall occurrence of T. gallinarum in poultry was 1.2% (22/1910), with infection rates of 2.1% (17/829) in chickens, 0.2% (1/487) in ducks, and 0.7% (4/594) in geese. The constructed phylogeny tree using the concatenated ITS1-5.8S-ITS2 region and SSU rRNA indicated the T. gallinarum isolates detected in this study were closely related to previously defined genogroups A, D, and E, respectively. Nine (0.5%) fecal samples were positive for T. gallinae, with infection rates of 0.8% (7/829) in chickens, 0.4% (2/487) in ducks, and 0% (0/594) in geese. Sequence and phylogenetic analysis showed that four T. gallinae ITS1-5.8S-ITS2 sequences obtained from chicken feces and one duck fecal sample belonged to genotype ITS-OBT-Tg-1. This is the first report of the prevalence and genetic characterization of T. gallinarum and T. gallinae in free-range chickens, ducks, and geese in China.

Prevalence of trichomonads in the cloaca of wild wetland birds in the Netherlands

Severe granulomatosis in productive layer chickens due to Tetratrichomonas gallinarum strain 13/16632 infection occurred in 2013 and 2017 on farms situated in a wetland area in the Netherlands. We hypothesized that wetland birds could be the source of the infection. Therefore, a prevalence study on trichomonads was performed by analysing cloaca swabs of 526 birds belonging to 13 species of wetland birds. The number of birds sampled ranged from 1 to 275 per species. Birds were sampled at 15 locations in the Netherlands. DNA extracted from the cloaca swabs was subjected to nested PCR using trichomonad-specific primers targeting the internal transcribed spacer 1 (ITS1)-5.8S rRNA-ITS2 region followed by cloning and sequencing. In nine bird species, trichomonads were detected; the overall prevalence was 9% (47/526), while the prevalence in the five species for which a substantial number of birds were examined (at least 39 per species) ranged from 4% to 24%. Three trichomonad species were found: T. gallinarum, Trichomonas tenax and Simplicimonas sp. of which T. gallinarum dominated. The virulent T. gallinarum strain 13/16632 was not detected, but closely related strains were. Phylogenetic analysis revealed that all T. gallinarum isolates belonged to two clusters within lineage 15 of Tetratrichomonas lineages. All T. tenax isolates were identical and clustered with reference strain H95, while Simplicimonas sp. isolates showed large genetic diversity. Some isolates may represent a new species of the genus Simplicimonas. We conclude that trichomonads are widespread amongst wetland birds, raising the question, amongst others, of their relevance for commercial poultry. RESEARCH HIGHLIGHTSTrichomonads occur among wild wetland birds in the Netherlands.T. gallinarum is the dominant trichomonad species in the cloaca of wetland birds.Some T. gallinarum isolates are closely related to a strain causing granulomas in layer chickens.Some isolates may represent a new species of the genus Simplicimonas.