First case report of Metorchis orientalis from Black Swan

Abstract

Metorchis orientalis belongs to the genus Metorchis of Opisthorchiidae, which mainly parasitizes in liver and bile ducts of waterfowl, causing liver dysfunction of the host. It has been reported that M. orientalis also infects humans. As a natural species in Australia and a popular ornamental animal, Black Swan ( Cygnus atratus ) has been imported into many countries. At present there has been no report of M. orientalis infection in Black Swan. In the present study M. orientalis infection in Black Swan was identified by a combination of different techniques, including morphological observation and molecular analysis. M. orientalis adults were found in the gallbladder and bile duct of a three-year-old female Black Swan, which was further confirmed by internal transcribed spacer (ITS) sequence analysis. In addition, the intermediate and definitive hosts of M. orientalis from the ‘Qing’ lake (a man-made lake in Changchun, China) that Black Swan lived were investigated and the infection route was preliminarily determined. Parafossarulus striatulus functioned as the first intermediate host which contained M. orientalis DNA, and fishes such as Pseudorasbora parva and Rhodeinae served as the second intermediate hosts with M. orientalis metacercariae in the fish flesh. M. orientalis eggs were found in the feces of three other Swans and six ducks that lived in the ‘Qing’ lake. This was the first reported case about M. orientalis infection of Black Swan. Our study described the course of the infection and provided new information about potential carriers and disseminators of M. orientalis .

Prevalence of fish-borne zoonotic trematode infection in Jilin Province, China

“…The prevalence of M. orientalis was higher in the reservoirs than in other water sources in our study due to the abundance of water, fish resources, and a large number of wild birds. M. orientalis is transmitted in a variety of wild birds ( Wang et al, 2020 ), which may be responsible for the high prevalence of M. orientalis in these reservoirs in our study. The prevalence of E. japonicus was higher in the wetlands than in other water sources due to the rich biodiversity of the wetland park, which had all the hosts necessary for the prevalence of E. japonicus .…”

“…The phylogenetic tree for ITS genes of FZTs was reconstructed using MEGA X software. The methods of maximum likelihood (ML), maximum parsimony (MP) and neighbor joining (NJ) were used for phylogenetic construction, and the initial trees were automatically obtained by selecting the topology with a superior log likelihood value ( Wang et al, 2020 ).…”

Integrative Transcriptomics and Proteomics Analyses to Reveal the Developmental Regulation of Metorchis orientalis: A Neglected Trematode With Potential Carcinogenic Implications

“…Interestingly, signaling pathways associated with “liver fibrosis” were also identified, namely the TGF-β signaling pathway (44 genes; two proteins). Similar to O. felineus and C. sinensis , M. orientalis can caused liver fibrosis during chronic infection ( Wang et al., 2020 ). Previous studies showed that liver fibrosis was orchestrated by a complex network of signaling pathways involved in regulating the deposition of extracellular matrix ( Yan et al., 2015 ).…”

Morpho-Molecular Features and Phylogenetic Relationships of Metorchis butoridi Oschmarin, 1963 (Trematoda: Opisthorchiidae) from East Asia

“…The life cycles and morphology of developmental stages were described for both species native to East Asia, M. taiwanensis and M. ussuriensis . Molecular characteristics were only obtained from M. ussuriensis and M. orientalis [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…These authors considered the molecular markers of metacercariae from naturally infected fish in China to belong to M. orientalis . Subsequently, molecular data for flukes identified as M. orientalis , obtained using metacercariae or adult worms from naturally infected animals, have been published by Na et al [ 12 ], Qiu et al [ 13 ], Qiu et al [ 14 ], and Wang et al [ 15 ]. Except for the article by Wang et al [ 15 ], other authors did not provide morphological data on the trematodes from which they had described molecular characteristics.…”