Can the same species of Platynosomum (Trematoda: Dicrocoeliidae) infect both mammalian and avian hosts?

Abstract

The importance of platynosomiasis has increased in feline veterinary practice, but aspects related to the specificity of Platynosomum spp. in definitive hosts requires further study. Although morphological traits suggest that the same species, P. illiciens, may infect both birds and mammals, the synonymies previously proposed have not been widely accepted, likely because host specificity is assumed. In addition, the name P. fastosum has frequently been used for parasites recovered from mammals. In the present study, metacercariae (n= 100/animal) of P. illiciens recovered from lizards (Hemidactylus mabouia) in Brazil were fed to Australian parakeets (Melopsittacus undulatus) and mice. Two parasites were recovered from the liver of one M. undulatus specimen during a necropsy that was performed 105 days after infection, and all mice were found to be infected with 37 ± 12 (18-48) parasites. The morphology of the P. illiciens obtained from the parakeet was similar to that of parasites obtained from mice and those described previously from naturally infected birds and mammals. Non-specificity of P. illiciens in hosts is discussed briefly, based on the parasitological and morphological results obtained during the avian experimental platynosomiasis and the epidemiology and geographical distribution of this parasite.

Experimental platynosomosis: Characterization of parasite development in the mouse model

“…The experimental susceptibility of mice to Platynosomum species have been shown by Maldonado (1945), Eckerlin and Leigh (1962) and, more recently, by Pinto et al (2014Pinto et al ( , 2015; however, these studies were not primarily performed with the aim of increasing the knowledge of the aspects of the hostparasite relationship in a laboratory rodent model. Regarding other experimental hosts, Eckerlin and Leigh (1962) reported the experimental susceptibility of opossum [Didelphis virginiana (Kerr, 1792)] and skunk [Spilogale putorius (Linnaeus, 1758)] in the annals of a meeting, but a comparative analysis of the susceptibility of the host to infection and the morphology of the parasites obtained from these different hosts were not provided.…”

“…Morphological polymorphisms have been reported in Platynosomum spp., and the factors as parasite age, host species (phenotypic plasticity), and differences in the process of fixation of the parasites have been discussed as possible factors related to these variations (Sitko, 1998;Pinto et al, 2015). In the present study, the kinetics of P. illiciens growth in mice were examined from 60 to 240 DPI.…”

Platynosomum fastosum (Trematoda: Dicrocoeliidae) from Cats in Vietnam: Morphological Redescription and Molecular Phylogenetics

“…P. fastosum was treated to be synonymous with other dicrocoeliid species because of intraspecific morphological variations [11]. Maldonado [12] treated 3 Platynosomum species, i.e., P. fastosum , P. concinnum (Braun, 1901), and P. illiciens (Braun, 1901), recovered in the gallbladder and bile ducts of cats, as the same species.…”

“…symmetricum , and Concinnum concinnum , were also considered to be the same species as P. fastosum [1]. Recently, Pinto et al [11] mentioned that no significant morphological differences were observed between P. fastosum and P. illiciens even though they parasitize different host species; mammals and birds, respectively. There are, however, no molecular studies on Platynosomum spp.…”

Helminth parasites of Galictis cuja (Carnivora, Mustelidae), from localities in the Atlantic forest of Brazil

“…This author therefore considered all these species to be junior synonyms of P. illiciens. Pinto et al (2016) also considered that the morphometric differences observed in these species of Platynosomum were insufficient for specific differentiation, and stated that P. illiciens is a species with wide geographic distribution and host range, parasitizing both birds and mammals. In carnivore mammals from Brazil, P. illiciens has been previously reported as a parasite of G. vittata in the state of Rio de Janeiro (TRAVASSOS, 1944;TRAVASSOS et al, 1969;VIEIRA et al, 2008), of P. yagouaroundi in the state of Pernambuco (BARBOSA & PONTUAL, 1949;RODRIGUES, 1963;VIEIRA et al, 2008).…”