Morphological and Molecular Characterization of Paragonimus skrjabini Complex from Yunnan, China: A Brief Report

Abstract

Purpose To perform environmental sampling and molecular identification of Paragonimus in endemic regions, which may help in minimizing transmission among humans. Methods Mountain crabs from the genus Potamiscus were collected and the encysted metacercariae were extracted and subjected to morphological identification, followed by animal inoculation in Sprague–Dawley (SD) rats. After 112 days of infection, animals were killed and adult worms were extracted from lungs and muscles. The morphology of adult worms was characterized by microscopy and molecular identification was done by polymerase chain reaction, followed by sequencing of cox1 and ITS2 genes. Phylogenetic analysis was done by maximum parsimony method. Results A total of 447 crabs were captured from the streams of Tongchang Town, Jinping County, Yunnan Province, China. The infection rate was found to be 41% (186 out of 447 crabs). The metacercariae of Paragonimus skrjabini was identified by the characteristics round or spherical encysted form measuring 410 to 460 × 400 to 460 µm. After animal infection in SD rats, adults were presumptively confirmed to be P. skrjabini, which was also confirmed by gene amplification and sequence analysis of cox1 and ITS2 regions. Paragonimus skrjabini clustered with previously reported P. skrjabini from Yunnan and Vietnam. The confidence values of their branches were > 95%. Phylogenetic analysis of the ITS2 region revealed two distinct clusters with distinct geographical grouping. Phylogenetic analysis with the combined data sets reiterated the geographical grouping with P. skrjabini from Yunnan clustering with strains from Vietnam. Conclusion Metacercariae of P. skrjabini was discovered in freshwater crabs in Yunnan province, China, and the strains were phylogenetically related to P. skrjabini from Vietnam.

General overview of the current status of human foodborne trematodiasis

“…Phylogenetic studies revealed that there exists a P. skrjabini complex, which includes P. skrjabini, P. skrjabini miyazakii and P. proliferus (syn. P. hocuoensis ) (Doanh et al ., 2013b ; Yang et al ., 2021 ; Shu et al ., 2021 a ). P. skrjabini is now known to occur in China, Thailand, Vietnam and northeast India (Singh et al ., 2006 ; Doanh et al ., 2013b ; Blair, 2019 ).…”

“…( 2015 ) reviewed 46 P. skrjabini miyazakii patients reported from 1974 to 2009 having pulmonary involvement. Phylogenetic studies revealed that P. skrjabini miyazakii is clearly included among the P. skrjabini complex (Blair et al ., 2005 ; Doanh et al ., 2013b ; Yang et al ., 2021 ; Shu et al ., 2021 a ; 2021 b ). Freshwater crabs, Geothelphusa dehaani carry the metacercariae (Blair et al ., 1999a ).…”

Morphological and molecular characterization of mole crab (Genus: Emerita) in the Cilacap coastlines of Indonesia, with particular focus on genetic diversity of Emerita sp. nov.

“…taxonomy and systematic utilized morphological data during species characterization (Erlank et al 2018;Shu et al 2022). In some animal groups, morphology characteristics are entirely satisfactory (Chan et al 2016;Mauroka et al 2018;Korovchinsky 2019).…”