Three monophyletic clusters in Retortamonas species isolated from vertebrates

• Published in: Parasitology international 2019-04, Vol.69, p.93-98
• Main Authors: Hendarto, Joko, Mizuno, Tetsushi, Hidayati, Anggi P.N., Rozi, Ismail E., Asih, Puji B.S., Syafruddin, Din, Yoshikawa, Hisao, Matsubayashi, Makoto, Tokoro, Masaharu
• Format: Article
• Language: English
• Subjects: Fornicata; Molecular taxonomy; Retortamonadida; Retortamonas intestinalis; Small subunit of ribosomal RNA
• ISSN: 1383-5769; 1873-0329
• DOI: 10.1016/j.parint.2018.12.004

Retortamonas spp. has been reported as an intestinal parasite among various host organisms, including humans; however, its intra-genus molecular diversity has not yet been elucidated. Haplotypes of the 18S small subunit ribosomal RNA locus (1836–1899 bp) of Retortamonas spp. from humans (n = 8), pigs (n = 6), dogs (n = 1), goats (n = 16), water buffalos (n = 23), cattle (n = 7), rats (n = 3), and chickens (n = 5) were analyzed with references isolated from non-human mammals, amphibians, and insects. Phylogenetic and network analyses revealed a statistically supported three cluster formation among the vertebrate-isolated haplotypes, while insect-isolated haplotypes were independently clustered with Chilomastix. In the clade of vertebrate isolates, assemblage A (amphibian genotype), which included the amphibian references, was addressed as an out-group of the other clusters. Assemblage B (mammalian and chicken genotype) included most haplotypes from various mammals including humans with the haplotypes isolated from a chicken. Human isolates were all classified into this assemblage, thus assemblage B might correspond to R. intestinalis. Assemblage C (bovine genotype), which included specific haplotypes from water buffalos and cattle, was addressed as a sister lineage of assemblage B. Among the diversified haplotypes of assemblage B, a specific haplotype, which was identified from multiple host mammals (humans, dogs, pigs, cattle, water buffalos, elks, goats, and rats), indicates the potential zoonotic transmission of the Retortamonas among them. The genotyping classification of retortamonads could contribute to a better understanding of its molecular epidemiology, especially among humans and related host organisms. [Display omitted] •The polyphyletic features of current Retortamonas spp. were confirmed as separated clusters.•Retortamonads from vertebrates were clustered with diplomonads, while the ones from insects were with Chilomastix.•Three cluster formation of genetic haplotypes of Retortamonas spp. isolated from vertebrates were confirmed.•Assemblage (ass.) A (amphibian genotype) and ass. C (bovine genotype) are host specific genotypes.•Ass. B [mammalian (including human) and avian genotype] might be correspond to Retortamonas intestinalis.