Parasites, Hosts and Diseases

The Korea Society for Parasitology and Tropical Medicine (대한기생충학·열대의학회)
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Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) from Riparian People along the Mekong River in Cambodia

  • Cho, Jaeeun (Institute of Parasitic Diseases, Korea Association of Health Promotion) ;
  • Jung, Bong-Kwang (Institute of Parasitic Diseases, Korea Association of Health Promotion) ;
  • Chang, Taehee (Institute of Parasitic Diseases, Korea Association of Health Promotion) ;
  • Sohn, Woon-Mok (Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine) ;
  • Sinuon, Muth (National Center for Parasitology, Entomology and Malaria Control) ;
  • Chai, Jong-Yil (Institute of Parasitic Diseases, Korea Association of Health Promotion)
  • Received : 2020.07.11
  • Accepted : 2020.07.29
  • Published : 2020.08.31
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Abstract

Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) is described based on adult flukes collected from humans residing along the Mekong River in Cambodia. Total 256 flukes were collected from the diarrheic stool of 6 echinostome egg positive villagers in Kratie and Takeo Province after praziquantel treatment and purging. Adults of the new species were 9.0-13.1 (av. 11.3) mm in length and 1.3-2.5 (1.9) mm in maximum width and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternative rows), including 5 end group spines. The eggs in feces and worm uterus were 98-132 (117) ㎛ long and 62-90 (75) ㎛ wide. These morphological features closely resembled those of Echinostoma revolutum, E. miyagawai, and several other 37-collar-spined Echinostoma species. However, sequencing of the nuclear ITS (ITS1-5.8S rRNA-ITS2) and 2 mitochondrial genes, cox1 and nad1, revealed unique features distinct from E. revolutum and also from other 37-collar-spined Echinostoma group available in GenBank (E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG). Thus, we assigned our flukes as a new species, E. mekongi. The new species revealed marked variation in the morphology of testes (globular or lobulated), and smaller head collar, collar spines, oral and ventral suckers, and cirrus sac compared to E. revolutum and E. miyagawai. Epidemiological studies regarding the geographical distribution and its life history, including the source of human infections, remain to be performed.

Keywords

References

  1. Chai JY, Cho J, Chang T, Jung BK, Sohn WM. Taxonomy of Echinostoma revolutum and 37-collar-spined Echinostoma spp.: a historical review. Korean J Parasitol 2020; 58: 343-371. https://doi.org/10.3347/kjp.2020.58.4.343
  2. Chai JY. Human Intestinal Flukes. Chapter 2. Echinostomes. The Netherlands. Springer Nature B.V. 2019, pp 169-343.
  3. Chai JY. Echinostomes in humans. In Fried B, Toledo R, eds, The Biology of Echinostomes. New York, USA. Springer. 2009, pp 147-183.
  4. Kanev I. Life-cycle, delimitation and redescription of Echinostoma revolutum (Froelich, 1802) (Trematoda: Echinostomatidae). Syst Parasitol 1994; 28: 125-144. https://doi.org/10.1007/BF00009591
  5. Nagataki M, Tantrawatpan C, Agatsuma T, Sugiura T, Duenngai K, Sithithaworn P, Andrews RH, Petney TN, Saijuntha W. Mitochondrial DNA sequences of 37 collar-spined echinostomes (Digenea: Echinostomatidae) in Thailand and Lao PDR reveals presence of two species: Echinostoma revolutum and E. miyagawai. Infect Genet Evol 2015; 35: 56-62. https://doi.org/10.1016/j.meegid.2015.07.022
  6. Georgieva S, Blasco-Costa I, Kostadinova A. Molecular characterization of four echinostomes (Digenea: Echinostomatidae) from birds in New Zealand, with descriptions of Echinostome novaezealandense n. sp. and Echinoparyphium poulini n. sp. Syst Parasitol 2017; 94: 477-497. https://doi.org/10.1007/s11230-017-9712-x
  7. Kostadinova A, Herniou EA, Barrett J, Littlewood DTJ. Phylogenetic relationships of Echinostoma Rudolphi, 1809 (Digenea: Echinostomatidae) and related genera re-assessed via DNA and morphological analyses. Syst Parasitol 2003; 54: 159-176. https://doi.org/10.1023/A:1022681123340
  8. Georgieva S, Selbach C, Faltynkova A, Soldanova M, Sures B, Skirnisson K, Kostadinova A. New cryptic species of the 'revolutum' group of Echinostoma (Digenea: Echinostomatidae) revealed by molecular and morphological data. Parasit Vectors 2013; 6: 64. https://doi.org/10.1186/1756-3305-6-64
  9. Georgieva S, Faltynkova A, Brown R, Blasco-Costa I, Soldanova M, Sitko J, Scholz T, Kostadinova A. Echinostoma 'revolutum' (Digenea: Echinostomatidae) species complex revisited: species delimitation based on novel molecular and morphological data gathered in Europe. Parasit Vectors 2014; 7: 520. https://doi.org/10.1186/s13071-014-0520-8
  10. Detwiler JT, Bos DH, Minchella DJ. Revealing the secret lives of cryptic species: examining the phylogenetic relationships of echinostome parasites in North America. Mol Phylogenet Evol 2010; 55: 611-620. https://doi.org/10.1016/j.ympev.2010.01.004
  11. Detwiler JT, Zajac AM, Minchella DJ, Belden LK. Revealing cryptic parasite diversity in a definitive host: echinostomes in muskrats. J Parasitol 2012; 98: 1148-1155. https://doi.org/10.1645/GE-3117.1
  12. Morgan JA, Blair D. Mitochondrial ND1 gene sequences used to identify echinostome isolates from Australia and New Zealand. Int J Parasitol 1998; 28: 493-502. https://doi.org/10.1016/S0020-7519(97)00204-X
  13. Saijuntha W, Sithithaworn P, Duenngai K, Kiatsopit N, Andrews RH, Petney TN. Genetic variation and relationships of four species of medically important echinostomes (Trematoda: Echinostomatidae) in South-East Asia. Infect Genet Evol 2011; 11: 375-381. https://doi.org/10.1016/j.meegid.2010.11.009
  14. Noikong W, Wongsawad C, Chai JY, Saenphet S, Trudgett A. Molecular analysis of echinostome metacercariae from their second intermediate host found in a localised geographic region reveals genetic heterogeneity and possible cryptic speciation. PLoS Negl Trop Dis 2014; 8: e2778. https://doi.org/10.1371/journal.pntd.0002778
  15. Mohanta UK, Watanabe T, Anisuzzaman, Ohari Y, Itagaki T. Characterization of Echinostoma revolutum and Echinostoma robustum from ducks in Bangladesh based on morphology, nuclear ribosomal ITS2 and mitochondrial nad1 sequences. Parasitol Int 2019; 69: 1-7. https://doi.org/10.1016/j.parint.2018.11.002
  16. Morgan JA, Blair D. Relative merits of nuclear ribosomal internal transcribed spacers and mitochondrial CO1 and ND1 genes for distinguishing among Echinostoma species (Trematoda). Parasitology 1998; 116: 289-297. https://doi.org/10.1017/S0031182097002217
  17. Chai JY, Sohn WM, Yong TS, Eom KS, Min DY, Hoang EH, Phammasack B, Insisiengmay B, Rim HJ. Echinostome flukes recovered from humans in Khammouane Province, Lao PDR. Korean J Parasitol 2012; 50: 269-272. https://doi.org/10.3347/kjp.2012.50.3.269
  18. Faltynkova A, Georgieva S, Soldanova M, Kostadinova A. A re-assessment of species diversity within the 'revolutum' group of Echinostoma Rudolphi, 1809 (Digenea: Echinostomatidae) in Europe. Syst Parasitol 2015; 90: 1-25. https://doi.org/10.1007/s11230-014-9530-3
  19. Luton K, Walker D, Blair D. Comparisons of ribosomal internal transcribed spacers from two congeneric species of flukes (Platyhelminthes: Trematoda: Digenea). Mol Biochem Parasitol 1992; 56: 323-328. https://doi.org/10.1016/0166-6851(92)90181-I
  20. Tamura K, Stecher G, Peterson D, Filipski A, Kumar S. MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Mol Biol Evol 2013; 30: 2725-2729. https://doi.org/10.1093/molbev/mst197
  21. Yamaguti S. Studies on the helminth fauna of Japan. Part 3. Avian trematodes, II. Jpn J Zool 1934; 5: 542-583.
  22. Yamaguti S. Studies on the helminth fauna of Japan. Part 5. Trematodes of birds, III. Jpn J Zool 1935; 6: 159-182.
  23. Sandground JH, Bonne C. Echinostoma lindoensis n. sp., a new parasite of man in the Celebes with an account of its life history and epidemiology. Am J Trop Med Hyg 1940; 20: 511-536. https://doi.org/10.4269/ajtmh.1940.s1-20.511
  24. Kanev I, Dimitrov V, Radev V, Fried B. Redescription of Echinostoma jurini (Skvortzov, 1924) with a discussion of its identity and characteristics. Ann Naturhist Mus Wien 1995; 97B: 37-53.
  25. Reddy DB, Ranganaykamma I, Venkataratnam D. Artyfechinostomum mehrai infestation in man. J Trop Med Hyg 1964; 67: 58-59.
  26. Sohn WM, Kim HJ, Yong TS, Eom KS, Jeong HG, Kim JK, Kang AR, Kim MR, Park JM, Ji SH, Sinuon M, Socheat D, Chai JY. Echinostoma ilocanum infection in Oddar Meanchey Province, Cambodia. Korean J Parasitol 2011; 49: 187-190. https://doi.org/10.3347/kjp.2011.49.2.187
  27. Sohn WM, Chai JY, Yong TS, Eom KS, Yoon CH, Sinuon M, Socheat D, Lee SH. Echinostoma revolutum infection in children, Pursat Province, Cambodia. Emerg Infect Dis 2011; 17: 117-119. https://doi.org/10.3201/eid1701.100920
  28. Anh NTL, Phuong NT, Murrell KD, Johansen MV, Dalsgaard A, Thu LT, Chi TTK, Thamsborg SM. Animal reservoir hosts and fish-borne zoonotic trematode infections on fish farms, Vietnam. Emerg Infect Dis 2009; 15: 540-546. https://doi.org/10.3201/eid1504.081147
  29. Anh NTL, Madsen H, Dalsgaard A, Phuong NT, Thanh DTH, Murrell KD. Poultry as reservoir hosts for fishborne zoonotic trematodes in Vietnamese fish farms. Vet Parasitol 2010; 169: 391-394. https://doi.org/10.1016/j.vetpar.2010.01.010
  30. Chai JY, Sohn WM, Na BK, De NV. Echinostoma revolutum: metacercariae in Filopaludina snails from Nam Dinh Province, Vietnam, and adults from experimental hamsters. Korean J Parasitol 2011; 49: 449-455. https://doi.org/10.3347/kjp.2011.49.4.449
  31. Sayasone S, Tesana S, Utzinger J, Hatz C, Akkhavong K, Odermatt P. Rare human infection with the trematode Echinochasmus japonicus in Lao PDR. Parasitol Int 2009; 58: 106-109. https://doi.org/10.1016/j.parint.2008.11.001
  32. Sohn WM, Chai JY, Na BK, Yong TS, Eom KS, Park H, Min DY, Rim HJ. Echinostoma macrorchis in Lao PDR: metacercariae in Cipangopaludina snails and adults from experimentally infected animals. Korean J Parasitol 2013; 51: 191-196. https://doi.org/10.3347/kjp.2013.51.2.191
  33. Chai JY, Sohn WM, Cho J, Eom KS, Yong TS, Min DY, Hoang EH, Phammasack B, Insisiengmay B, Rim HJ. Echinostoma ilocanum infection in two residents of Savannakhet Province, Lao PDR. Korean J Parasitol 2018; 56: 77-81.
  34. Chai JY, Jung BK, Chang T, Shin H, Sohn WM, Eom KS, Yong TS, Min DY, Phommasack B, Insisiengmay B, Rim HJ. Echinostoma aegyptica (Trematoda: Echinostomatidae) infection in five riparian people in Savannakhet Province, Lao PDR. Korean J Parasitol 2020; 58: 67-72. https://doi.org/10.3347/kjp.2020.58.1.67
  35. Chai JY, Chang T, Jung BK, Shin H, Sohn WM, Eom KS, Yong TS, Min DY, Phommasack B, Insisiengmay B, Rim HJ. Echinochasmus caninus n. comb. (Trematoda: Echinostomatidae) infection in eleven riparian people in Khammouane Province, Lao PDR. Korean J Parasitol 2019; 57: 451-456. https://doi.org/10.3347/kjp.2019.57.4.451
  36. Bhaibulaya M, Harinasuta C, Trirachantra S. The finding of Echinostoma revolutum infection in man in Thailand. J Med Assoc Thailand 1966; 49: 83.
  37. Radomyos P, Radomyos B, Tungtrongchitr A. Multi-infection with helminths in adults from northeast Thailand as determined by post-treatment fecal examination of adult worms. Trop Med Parasitol 1994; 45: 133-135.
  38. Saijuntha W, Tantrawatpan C, Sithithaworn P, Andrews RH, Petney TN. Genetic characterization of Echinostoma revolutum and Echinoparyphium recurvatum (Trematoda: Echinostomatidae) in Thailand and phylogenetic relationships with other isolates inferred by ITS1 sequence. Parasitol Res 2011; 108: 751-755. https://doi.org/10.1007/s00436-010-2180-8
  39. Buddhachat K, Chontananarth T. Is species identification of Echinostoma revolutum using mitochondrial DNA barcoding feasible with high-resolution melting analysis? Parasitol Res 2019; 118: 1799-1810. https://doi.org/10.1007/s00436-019-06322-w
  40. World Health Organization. Basic Laboratory Methods in Medical Parasitology. Geneva, Switzerland. World Health Organization. 1991, pp 26.

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