• Parasites, Hosts and Diseases
• /
• v.58 no.4
• /
• pp.431-443
• /
• 2020

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.

• Journal of Forest and Environmental Science
• /
• v.33 no.1
• /
• pp.49-65
• /
• 2017

Overall, 3,950 mushroom specimens were collected from the Central Cardamom Protected Forest (CCPF) in Koh Kong province, the Kirirom National Park (KNP) in Kampong Speu province, the Seima Biodiversity Conservation Area (SBCA) in Kratie province, the Mondulkiri Protected Forest (MPF) in Mondulkiri province, the Phnom Bokor National Park (PBNP) in Kampot province, the Western Siem Pang Protected Forest (SPPF) in Stung Treng province, the Ream National Park (RNP) in Sihanoukville province of Cambodia from 2009 to 2014, and then they were identified and classified into 302 species, 165 genera, and 64 families by morphological and genetical characteristics. The mushrooms belongs to Ascomycota were classified into 26 species, 14 genera, and 10 families, while those belongs to Basidiomycota were classified into 276 species, 151 genera, and 54 families, respectively. Among these mushrooms, the most species-rich families are Polyporaceae (26.2%), Marasmiaceae (9.1%), Ganodermataceae (7.7%), Hymenochaetaceae (7.5%), and Mycenaceae (7.1%), and comprised 57.5% of the total specimens identified.

• Parasites, Hosts and Diseases
• /
• v.59 no.1
• /
• pp.47-53
• /
• 2021

Echinostoma mekongi was reported as a new species in 2020 based on specimens collected from humans in Kratie and Takeo Province, Cambodia. In the present study, its metacercarial stage has been discovered in Filopaludina martensi cambodjensis snails purchased from a local market nearby the Tonle Sap Lake, Pursat Province, Cambodia. The metacercariae were fed orally to an experimental hamster, and adult flukes were recovered at day 20 post-infection. They were morphologically examined using light and scanning electron microscopes and molecularly analyzed by sequencing of their mitochondrial cox1 and nad1 genes. A total of 115 metacercariae (1-8 per snail) were detected in 60 (60.0%) out of 100 Filopaludina snails examined. The metacercariae were round, 174 ㎛ in average diameter (163-190 ㎛ in range), having a thin cyst wall, a head collar armed with 37 collar spines, and characteristic excretory granules. The adult flukes were elongated, ventrally curved, 7.3 (6.4-8.2)×1.4 (1.1-1.7) mm in size, and equipped with 37 collar spines on the head collar (dorsal spines in 2 alternating rows), being consistent with E. mekongi. In phylogenetic analyses, the adult flukes showed 99.0-100% homology based on cox1 sequences and 98.9-99.7% homology based on nad1 sequences with E. mekongi. The results evidenced that F. martensi cambodjensis snails act as the second intermediate host of E. mekongi, and hamsters can be used as a suitable experimental definitive host. As local people favor to eat undercooked snails, these snails seem to be an important source of human infection with E. mekongi in Cambodia.