title: Specific diagnosis of Opisthorchis viverrini using loop-mediated isothermal amplification (LAMP) targeting parasite microsatellites.
abstract: Opisthorchis viverrini and other food-borne trematode infections are major health problems in Thailand, the Lao People's Democratic Republic, Vietnam and Cambodia. Differential diagnosis of O. viverrini based on the microscopic observation of parasite eggs is difficult in areas where Clonorchis sinensis and minute intestinal flukes coexist. Recently, loop-mediated isothermal amplification (LAMP) has been widely used for detection and identification of trematode for its simple method that is useful in low-resource or field settings. We have reported ITS1-LAMP assay to detect O. viverrini infection from human feces. The sensitivity and specificity of the test was 100% and 61.5%. The sensitivity of the test appeared to be higher than microscopic egg examination; however non-specific amplification from other parasites could not be ruled out. We therefore targeted microsatellites of O. viverrini that is a species specific sequence. By using hydroxyl naphthol blue (HNB)-LAMP, O. viverrini microsatellite 6 (OVMS6) could specifically amplify DNA from O. viverrini genome, but not other parasites such as C. sinensis, Opisthorchis felineus, Centrocestus caninus, Haplorchis taichui, Fasciola gigantica and Haplorchoodes sp. The detection limit of the test is 1 ng genomic DNA, which was 1000 times lower than the ITS1-LAMP, but targeting microstellites showed more specific detection of O. viverrini. In addition, the colorimetric LAMP assay was simple and effective; this makes it potentially applicable for point-of-care diagnosis.
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Arimatsu
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Sasithorn
authors.initials: S
authors.lastname: Kaewkes
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Thewarach
authors.initials: T
authors.lastname: Laha
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: banchob@kku.ac.th.
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
mesh_terms: D000818:Animals; D003003:Clonorchiasis / Q000175:diagnosis*; D003004:Clonorchis sinensis / Q000235:genetics*; D003530:Cyprinidae / Q000469:parasitology; D017931:DNA Primers / Q000235:genetics; D003937:Diagnosis, Differential; D005243:Feces / Q000469:parasitology; D006801:Humans; D058488:Metacercariae / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D009889:Opisthorchiasis / Q000175:diagnosis*; D009891:Opisthorchis / Q000235:genetics*; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D013785:Thailand
chemical_list: D017931:DNA Primers
keywords: LAMP; Microsatellite; Opisthorchis viverrini; Point-of-care diagnosis