Morphological and molecular identification of two Paragonimus spp., of which metacercariae concurrently found in a land crab, Potamiscus tannanti, collected in Yenbai Province, Vietnam.
Paragonimosis is an important food-borne zoonosis especially in Asian countries. Among Paragonimus species, Paragonimus westermani followed by P. skrjabini complex are the major pathogens for human paragonimosis in Asia. In addition, P. heterotremus is an important pathogen in southern China and the Indochina Peninsula and is the only proven species to cause human paragonimosis in Vietnam. During a recent survey in Yenbai Province in northern Vietnam, we found small and large types of Paragonimus metacercariae often concurrently in mountainous crabs, Potamiscus tannanti. Adult worms from those small and large metacercariae were obtained separately by experimental infection in dogs and cats. Morphological and molecular phylogenetic study based on sequences of ITS2 and a part of CO1 genes were performed for the identification of small and large metacercariae and their adults. The results showed that small metacercariae and their adults are completely identical with P. heterotremus in morphology and molecular genetic profiles. In contrast, large metacercariae and their adults have some morphological similarities with P. skrjabini and P. harinasutai, but are unidentifiable from each other by morphology alone. Molecular phylogenetic tree analyses on ITS2 and CO1 genes revealed that large metacercariae and their adults were grouped in the same clade and different from any known Paragonimus species. Although they share the same ancestor with P. skrjabini complex, their genetic distance was considerably different from two other known subspecies, P. skrjabini skrjabini and P. skrjabini miyazakii. Our results provide a new insight on the phylogeny of the genus Paragonimus.
Doanh
Pham Ngoc
PN
Department of Parasitology, Institute of Ecology and Biological Resources, Vietnamese Academy of Science and Technology, Hanoi, Vietnam. pndoanh@iebr.vast.ac.vn
Shinohara
Akio
A
Horii
Yoichiro
Y
Habe
Shigehisa
S
Nawa
Yukifumi
Y
The
Dang Tat
DT
Le
Nguyen Thi
NT
D000818:Animals; D003386:Brachyura / Q000469:parasitology*; D002415:Cats; D016000:Cluster Analysis; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D004285:Dogs; D003576:Electron Transport Complex IV / Q000235:genetics; D008969:Molecular Sequence Data; D010237:Paragonimiasis / Q000469:parasitology*; D010238:Paragonimus / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012758:Shellfish / Q000469:parasitology*; D014744:Vietnam
D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D003576:Electron Transport Complex IV