BACKGROUNDEchinococcosis, coenurosis and cysticercosis are debilitating diseases which prevail in China. Immunological diagnosis of metacestodosis is important in disease control. The 8-kDa glycoproteins from taeniid cestodes have successfully been used for diagnosis of human cysticercosis in immunological assays. The aim of the present study was to investigate genetic variations and phylogenetic relationships of the 8-kDa proteins for evaluating the possibility of utilizing these proteins as diagnostic antigens for other metacestode infections.

METHODSThe genes and complementary DNAs (cDNAs) encoding the 8-kDa proteins from Echinococcus (E.) granulosus, Taenia (T.) multiceps and T. hydatigena were amplified using PCR method. Their amplicons were cloned into the vector pMD18 and the positive clones were sequenced. Sequence data were analyzed with the SeqMan program, and sequence homology searches were performed using the BLAST program. Alignments were conducted using the ClustalX program, and the phylogenetic analyses were performed with the Protein Sequences Program and the Puzzle Program using the Neighbor-joining method.

RESULTSFifteen, 18 and 22 different genomic DNA sequences were identified as members of the 8-kDa protein gene family from E. granulosus, T. multiceps and T. hydatigena, respectively. Eight, four and six different cDNA clones respectively from E. granulosus, T. multiceps and T. hydatigena were characterized. Analysis of these sequences revealed 54 unique 8-kDa protein sequences. Phylogenetic trees demonstrated that the taeniid 8-kDa proteins are clustered into eight clades at least: Ts18, Ts14, TsRS1, TsRS2, T8kDa-1, T8kDa-2, T8kDa-3 and T8kDa-4.

CONCLUSIONWe found that the gene family encoding for the taeniid 8-kDa antigens is comprised of many members with high diversity, which will provide molecular evidence for cross-reaction or specific reaction among metacestode infections and may contribute to the development of promising immunological methods for diagnosis of metacestodosis.

Amino Acid Sequence ; Animals ; DNA, Helminth ; genetics ; Echinococcus granulosus ; genetics ; metabolism ; Genetic Variation ; genetics ; Glycoproteins ; chemistry ; classification ; genetics ; Helminth Proteins ; chemistry ; classification ; genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Homology, Amino Acid ; Taenia ; genetics ; metabolism

To determine the molecular phylogenic location of Plagiorchis muris, 28S D1 ribosomal DNA (rDNA) and mitochondrial cytochrome C oxidase subunit I (mtCOI) were sequenced and compared with other trematodes in the family Plagiorchiidae. The 28S D1 tree of P. muris was found to be closely related to those of P. elegans and other Plagiorchis species. And, the mtCOI tree also showed that P. muris is in a separate clade with genus Glypthelmins. These results support a phylogenic relationship between members of the Plagiorchiidae, as suggested by morphologic features.
Animals ; Base Sequence ; DNA, Helminth/chemistry/genetics ; DNA, Mitochondrial/chemistry/genetics ; Electron Transport Complex IV/chemistry/*genetics ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 28S/chemistry/*genetics ; Sequence Alignment ; Support, Non-U.S. Gov't ; Trematoda/classification/*genetics

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.
Adult ; Aged ; Animal Structures/anatomy & histology ; Animals ; Cluster Analysis ; Cyclooxygenase 1/genetics ; DNA, Helminth/chemistry/genetics ; DNA, Intergenic/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Diphyllobothriasis/parasitology ; Diphyllobothrium/*anatomy & histology/classification/*genetics/isolation & purification ; Female ; Helminth Proteins/genetics ; Humans ; Korea ; Male ; Microscopy ; Microscopy, Electron, Scanning ; Mitochondrial Proteins/genetics ; Phylogeny ; Sequence Analysis, DNA ; Sequence Homology

Mitochondrial genomes have been extensively studied for phylogenetic purposes and to investigate intra- and interspecific genetic variations. In recent years, numerous groups have undertaken sequencing of platyhelminth mitochondrial genomes. Haplorchis taichui (family Heterophyidae) is a trematode that infects humans and animals mainly in Asia, including the Mekong River basin. We sequenced and determined the organization of the complete mitochondrial genome of H. taichui. The mitochondrial genome is 15,130 bp long, containing 12 protein-coding genes, 2 ribosomal RNAs (rRNAs, a small and a large subunit), and 22 transfer RNAs (tRNAs). Like other trematodes, it does not encode the atp8 gene. All genes are transcribed from the same strand. The ATG initiation codon is used for 9 protein-coding genes, and GTG for the remaining 3 (nad1, nad4, and nad5). The mitochondrial genome of H. taichui has a single long non-coding region between trnE and trnG. H. taichui has evolved as being more closely related to Opisthorchiidae than other trematode groups with maximal support in the phylogenetic analysis. Our results could provide a resource for the comparative mitochondrial genome analysis of trematodes, and may yield genetic markers for molecular epidemiological investigations into intestinal flukes.
Animals ; Asia ; Codon, Initiator ; DNA, Mitochondrial/chemistry/genetics ; Gene Order ; Genes, Helminth ; *Genome, Mitochondrial ; Heterophyidae/*genetics/isolation & purification ; Humans ; Molecular Sequence Data ; Sequence Analysis, DNA

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.
Animals ; Base Sequence ; Cluster Analysis ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/*genetics ; Electron Transport Complex IV/*genetics ; Fasciola hepatica/*genetics/*isolation & purification ; Korea ; Molecular Sequence Data ; Oenanthe/*parasitology ; Phylogeny ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid

The present study was performed to describe 2 human cases infected by the horsehair worm, Parachordodes sp., in Japan. Two gordiid worms were collected in the vomit and excreta of an 80-year-old woman in November 2009 in Kyoto city, and in the mouth of 1-year-old boy in December 2009 in Nara city, Japan, respectively. Both worms were males having bifurcated posterior ends and male gonads in cross sectional specimens. They were identified as Parachordodes sp. (Nematomorpha: Chordodidae) based on the characteristic morphologies of cross sections and areoles in the cuticle. DNA analysis on 18S rRNA partial sequence arrangements was also carried out and both worms were assumed to be close to the genus Paragordionus based on tree analysis, and far from Gordius sp. which has already been reported in humans in Japan. DNA sequencing of the Parachordodes worm does not appear on the database; therefore, more information on the gene sequences of the genus Parachordodes from humans, animals, or intermediates is required.
Aged, 80 and over ; Animals ; Cluster Analysis ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Helminthiasis/*diagnosis/*parasitology/pathology ; Helminths/anatomy & histology/classification/genetics/*isolation & purification ; Humans ; Infant ; Japan ; Male ; Microscopy ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA

Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.
Animals ; Base Sequence ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Fasciola hepatica/anatomy & histology/genetics/*isolation & purification ; Molecular Sequence Data ; Oenanthe/growth & development ; *Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA ; Snails/growth & development/*parasitology

To gain information on retrotransposons in the genome of Paragonimus westermani, PCR was carried out with degenerate primers, specific to protease and reverse transcriptase (rt) genes of long-terminal-repeat (LTR) retrotransposons. The PCR products were cloned and sequenced, after which 12 different retrotransposon-related sequences were isolated from the trematode genome. These showed various degrees of identity to the polyprotein of divergent retrotransposon families. A phylogenetic analysis demonstrated that these sequences could be classified into three different families of LTR retrotransposons, namely, Xena, Bel, and Gypsy families. Of these, two mRNA transcripts were detected by reverse transcriptase-PCR, showing that these two elements preserved their mobile activities. The genomic distributions of these two sequences were found to be highly repetitive. These results suggest that there are diverse retrotransposons including the ancient Xena family in the genome of P. westermani, which may have been involved in the evolution of the host genome.
Amino Acid Sequence ; Animals ; Cloning, Molecular ; DNA, Helminth/analysis ; *Evolution, Molecular ; *Genome ; Molecular Sequence Data ; Paragonimus/*genetics ; Phylogeny ; RNA-Directed DNA Polymerase/chemistry/genetics ; Retroelements/*genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Terminal Repeat Sequences/*genetics

We compared the DNA sequence difference of isolates of Clonorchis sinensis from one Korean (Kimhae) and two Chinese areas (Guangxi and Shenyang). The sequences of nuclear rDNA (18S, internal transcribed spacer 1 and 2: ITS1 and ITS2) and mitochondrial DNA (cytochrome c oxidase subunit 1: cox1) were compared. A very few intraspecific nucleotide substitution of the 18S, ITS1, ITS2 and cox1 was found among three isolates of C. sinensis and a few nucleotide insertion and deletion of ITS1 were detected. The 18S, ITS1, ITS2 and cox1 sequences were highly conserved among three isolates. These findings indicated that the Korean and two Chinese isolates are similar at the DNA sequence level.
Animals ; Base Sequence ; China ; Clonorchis sinensis/enzymology/*genetics ; Comparative Study ; DNA, Helminth/chemistry/*genetics ; DNA, Mitochondrial/chemistry/*genetics ; DNA, Ribosomal/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry ; Electron Transport Complex IV/genetics ; Genetic Markers ; Korea ; Molecular Sequence Data ; RNA, Ribosomal, 18S/genetics ; Research Support, Non-U.S. Gov't ; Sequence Alignment ; Species Specificity ; *Variation (Genetics)

Dirofilaria immitis (heartworm) infections affect domestic dogs, cats, and various wild mammals with increasing incidence in temperate and tropical areas. More sensitive antibody detection methodologies are required to diagnose asymptomatic dirofilariasis with low worm burdens. Applying current transcriptomic technologies would be useful to discover potential diagnostic markers for D. immitis infection. A filarial homologue of the mammalian translationally controlled tumor protein (TCTP) was initially identified by screening the assembled transcriptome of D. immitis (DiTCTP). A BLAST analysis suggested that the DiTCTP gene shared the highest similarity with TCTP from Loa loa at protein level (97%). A histidine-tagged recombinant DiTCTP protein (rDiTCTP) of 40 kDa expressed in Escherichia coli BL21 (DE3) showed immunoreactivity with serum from a dog experimentally infected with heartworms. Localization studies illustrated the ubiquitous presence of rDiTCTP protein in the lateral hypodermal chords, dorsal hypodermal chord, muscle, intestine, and uterus in female adult worms. Further studies on D. immitis-derived TCTP are warranted to assess whether this filarial protein could be used for a diagnostic purpose.
Animal Structures/chemistry ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/chemistry/*genetics/immunology/*isolation & purification ; Cloning, Molecular ; Dirofilaria immitis/chemistry/*genetics/immunology ; Disease Models, Animal ; Dogs ; Escherichia coli/genetics ; Gene Expression ; Molecular Sequence Data ; Molecular Weight ; Recombinant Fusion Proteins/chemistry/genetics/immunology/isolation & purification ; Sequence Analysis, DNA ; Tumor Markers, Biological/chemistry/*genetics/immunology/*isolation & purification