Vet World   Vol.14   October-2021  Article-11

Parasitological and molecular characterization of the avian schistosomatid cercariae infecting lymnaeidae snails in Phayao, Northern Thailand

Background and Aim: Cercarial dermatitis or swimmer's itch is an allergic skin reaction caused by penetrating cercaria of animal blood flukes. It is considered as a zoonotic water-borne skin condition that is found globally. Among the schistosomatid trematodes, avian schistosomes are the most responsible for cercarial dermatitis. Very little is known regarding the occurrence of dermatitis-causing cercariae in Thailand. Therefore, the objective of this study was to preliminarily investigate the presence of larval blood fluke infection among local lymnaeidae snails in Phayao by the incorporation of morphological and molecular methods.

Materials and Methods: Overall 500 Radix (Lymnaea) rubiginosa (Michelin, 1831) were collected from freshwater reservoirs near Phayao Lake in San Kwan village in Phayao, Thailand, from October to December 2020. The snails were examined for avian blood fluke infection by the cercarial shedding technique followed by morphological and molecular characterization.

Results: Only one type of furcocercous cercaria was observed to emerge from six infected snails (1.2%). Our molecular analyses demonstrated that the emerging cercariae showed most similarity to either the 28S ribosomal RNA gene (28S rDNA) or cytochrome oxidase C subunit 1 gene (cox1 or COI) sequences to those of Trichobilharzia species. In addition, phylogenetic tree analyses of both loci revealed similar results; the emerging cercariae were consistently clustered together with Trichobilharzia regenti.

Conclusion: Our results clearly confirmed that the detected furcocercous cercariae belonged to the genus Trichobilharzia and displayed the highest homology to T. regenti. This study provides important data on the occurrence of dermatitis causing cercariae infection among local lymnaeidae snails, encouraging effective management, and control measures for this zoonotic infectious disease. Keywords: avian schistosome, cercarial dermatitis, furcocercous cercaria, swimmer's itch, Radix (Lymnaea) rubiginosa, Trichobilharzia regenti.

Keywords: avian schistosome, cercarial dermatitis, furcocercous cercaria, swimmer's itch, Radix (Lymnaea) rubiginosa, Trichobilharzia regenti.

How to cite this article: Japa O, Suwancharoen C, Bunsong T, Phuangsri C (2021) Parasitological and molecular characterization of the avian schistosomatid cercariae infecting lymnaeidae snails in Phayao, Northern Thailand, Veterinary World, 14(10): 2655-2661.

Received: 08-06-2021  Accepted: 07-09-2021     Published online: 20-10-2021

Corresponding author: Ornampai Japa   E-mail: ornampai.ja@up.ac.th

DOI: 10.14202/vetworld.2021.2655-2661

Copyright: Japa, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.