Morphological and Molecular Characteristics of Clinostomid Metacercariae from Korea and Myanmar

Abstract

Morphological and molecular characterization of clinostomid metacercariae (CMc) was performed with the specimens collected in fish from Korea and Myanmar. Total 6 batches of clinostomid specimens by the fish species and geographical localities, 5 Korean and 1 Myanmar isolates, were analyzed with morphological (light microscopy and SEM) and molecular methods (the cytochrome <i>c</i> oxidase 1 gene and internal transcribed spacer 1/5.8S rRNA sequence). There were some morphological variations among CMc specimens from Korea. However, some morphometrics, i.e., the size of worm body and each organ, ratio of body length to body width, and morphology of cecal lumens, were considerably different between the specimens from Korea and Myanmar. The surface ultrastructures were somewhat different between the specimens from Korea and Myanmar. The <i>CO</i>1 sequences of 5 Korean specimens ranging 728-736 bp showed 99.6-100% identity with <i>Clinostomum complanatum</i> (GenBank no. KM923964). They also showed 99.9-100% identity with <i>C. complanatum</i> (FJ609420) in the ITS1 sequences ranging 692-698 bp. Meanwhile, the ITS1 sequences of Myanmar specimen showed 99.9% identity with <i>Euclinostomum heterostomum</i> (KY312847). Five sequences from Korean specimens clustered with the <i>C. complanatum</i> genes, but not clustered with Myanmar specimens. Conclusively, it was confirmed that CMc from Korea were morphologically and molecularly identical with <i>C. complanatum</i> and those from Myanmar were <i>E. heterostomum</i>.

Cercarial dermatitis outbreak caused by ruminant parasite with intermediate snail host: schistosome in Chana, South Thailand

“…Humans may be infected with the parasite when eating raw or undercooked fish meat carrying the metacercarial stage. Therefore, this trematode must be considered not only for its losses in production and discards of fish, but also for its zoonotic potential (Hunter and Hunter 1935;Esch et al 2001;Wang et al 2017;Rosser et al 2018;Sohn et al 2019;de Souza et al 2020;Won et al 2020).…”