Morphologic and genetic identification of Diphyllobothrium nihonkaiense in Korea.
Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means 'long tapeworm of the East Sea' for this newly analyzed diphyllobothriid tapeworm in Korea.
Jeon
Hyeong-Kyu
HK
Department of Parasitology and Medical Research Institute, Chungbuk BK21 Biomedical Research Center, Chungbuk National University College of Medicine, Cheongju, Chungbuk 361-763, Korea.
Kim
Kyu-Heon
KH
Huh
Sun
S
Chai
Jong-Yil
JY
Min
Duk-Young
DY
Rim
Han-Jong
HJ
Eom
Keeseon S
KS
D000328:Adult; D000368:Aged; D000825:Animal Structures / Q000033:anatomy & histology; D000818:Animals; D016000:Cluster Analysis; D051545:Cyclooxygenase 1 / Q000235:genetics; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D021901:DNA, Intergenic / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004169:Diphyllobothriasis / Q000469:parasitology; D004170:Diphyllobothrium / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005260:Female; D015801:Helminth Proteins / Q000235:genetics; D006801:Humans; D007723:Korea; D008297:Male; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D024101:Mitochondrial Proteins / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
D018509:DNA, Helminth; D021901:DNA, Intergenic; D004275:DNA, Ribosomal; D015801:Helminth Proteins; D024101:Mitochondrial Proteins; D051545:Cyclooxygenase 1