Characterization of a human isolate of <i>Tritrichomonas foetus</i> (cattle/swine genotype) infected by a zoonotic opportunistic infection

Abstract

Tritrichomonas species flagellates (IMC strain) were isolated from the biliary tract of an individual who had developed cholecystitis as a complication of acquired agammaglobulinemia. Sequence analysis of Tritrichomonas sp. (IMC clone 2 (cl2)) was performed for several genetic regions including the ITS1-5.8S rDNA-ITS2 region, the cysteine protease (CP)-1, CP-2 and CP-4 to CP-9 genes, and the cytosolic malate dehydrogenase 1 gene. In addition to comparison of the variable-length DNA repeats in the isolate clone with those in T. foetus (Inui cl2) and the T. mobilensis (U.S.A.: M776 cl2) reference strains, this analysis showed that the Tritrichomonas sp. (IMC cl2) was T. foetus (cattle/swine genotype). Injection of T. foetus (IMC cl2) directly into the livers of CBA mice resulted in liver abscess formation on Day 7. Moreover, inoculation via orogastric intubation caused infection in the cecum on Day 5 in CBA mice co-infected with Entamoeba histolytica (HM-1: IMSS cl6). T. foetus (IMC cl2) was able to grow in YI-S medium for over 20 days, even at 5°C. These results indicate that the T. foetus isolate is able to survive in the feces and edible organ meat of the definitive host for a prolonged period of time, and it is possible that the parasite could infect humans.

Comparison and Recommendations for Use of Dientamoeba fragilis Real-Time PCR Assays

“…Eukaryotic OTUs in group 2 were predominantly limited to a number of fungi and Chordata, likely remnants from the patient's diet. The laboratory-developed real-time assay was shown to be cross-reactive with T. foetus (11) although no evidence of T. foetus sequences could be found, which is not surprising considering that zoonotic transmission to humans is opportunistic and uncommon (39). Ultimately, 18S diversity profiling ruled out the presence of any closely related trichomonad species that could account for cross-reactivity within the samples.…”

Novel genotype ofTritrichomonas foetusfrom cattle in Southern Africa

“…The presence of the novel T. foetus genotype prompted the characterization of cysteine proteinase 2 (CP2) locus of T. foetus previously recognized as the most divergent (22 nt differences) between the known ‘feline’ and ‘bovine’ genotypes (Šlapeta et al 2012; Suzuki et al 2016). Amplification of CP2 was successful for 36% (13/35) DNA samples that were considered positive for T. foetus using the qPCR assays.…”

Análisis filogenético de secuencias de Cistein-Proteasas de Tritrichomonas foetus, ¿salto de la barrera de especies?

“…Otro caso reportado en humano fue hecho en Japón, en donde se aisló T. foetus de conducto biliar de un paciente con colecistitis. Posterior al aislamiento se realizó genotipificación a las CP 1,2,4 y 9 y se comparó con las secuencias de T. foetus de ganado y cerdo dando como resultado genotipos iguales (8).…”

“…Existen reportes de infecciones oportunistas por parte de la Tritrichomonas foetus, en humanos inmunodeprimidos o inmunosuprimidos permitiendo la colonización de la T. foetus en sistema respiratorio (7). Sin embargo, todavía no está clara la ruta de infección y el genotipo de estos parásitos de acuerdo a su hospedero (8).…”