title: Retrotransposon OV-RTE-1 from the carcinogenic liver fluke Opisthorchis viverrini: potential target for DNA-based diagnosis.
abstract: Infections by the fish-borne liver flukes Opisthorchis viverrini and Clonorchis sinensis can lead to bile duct cancer. These neglected tropical disease pathogens occur in East Asia, with O. viverrini primarily in Thailand and Laos and C. sinensis in Cambodia, Vietnam, and China. Genomic information about these pathogens holds the potential to improve disease treatment and control. Transcriptome analysis indicates that mobile genetic elements are active in O. viverrini, including a novel non-Long Terminal Repeat (LTR) retrotransposon. A consensus sequence of this element, termed OV-RTE-1, was assembled from expressed sequence tags and PCR amplified genomic DNA. OV-RTE-1 was 3330 bp in length, encoded 1101 amino acid residues and exhibited hallmark structures and sequences of non-LTR retrotransposons including a single open reading frame encoding apurinic-apyrimidinic endonuclease (EN) and reverse transcriptase (RT). Phylogenetic analyses confirmed that OV-RTE-1 was member of the RTE clade of non-LTR retrotransposons. OV-RTE-1 is the first non-LTR retrotransposon characterized from the trematode family Opisthorchiidae. Sequences of OV-RTE-1 were targeted to develop a diagnostic tool for detection of infection by O. viverrini. PCR specific primers for detection of O. viverrini DNA showed 100% specificity and sensitivity for detection of as little as 5 fg of O. viverrini DNA whereas the PCR based approach showed 62% sensitivity and 100% specificity with clinical stool samples. The OV-RTE-1 specific PCR could be developed as a molecular diagnostic for Opisthorchis infection targeting parasite eggs in stool samples, especially in regions of mixed infection of O. viverrini and/or C. sinensis and minute intestinal flukes.
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Luyen
authors.initials: L
authors.lastname: Thi Phung
authors.affiliation: Centre for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland 4878, Australia.
authors.forename: Alex
authors.initials: A
authors.lastname: Loukas
authors.affiliation: Department of Microbiology, Immunology and Tropical Medicine, and Research Center for Neglected Tropical and Infectious Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Brindley
authors.affiliation: Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: thewa_la@kku.ac.th.
authors.forename: Thewarach
authors.initials: T
authors.lastname: Laha
mesh_terms: D000818:Animals; D018509:DNA, Helminth; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics; D019143:Evolution, Molecular; D005243:Feces / Q000469:parasitology; D015801:Helminth Proteins / Q000235:genetics*; D006801:Humans; D009889:Opisthorchiasis / Q000469:parasitology*; D009891:Opisthorchis / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D018626:Retroelements; D012680:Sensitivity and Specificity; D059467:Transcriptome
chemical_list: D018509:DNA, Helminth; D015801:Helminth Proteins; D018626:Retroelements; D012194:RNA-Directed DNA Polymerase; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase
keywords: Diagnosis; Feces; Liver fluke; Opisthorchis viverrini; Retrotransposon