Freshwater snails of the family Lymnaeidae play an important role in the transmission of fascioliasis worldwide. In Vietnam, 2 common lymnaeid species, Lymnaea swinhoei and Lymnaea viridis, can be recognized on the basis of morphology, and a third species, Lymnaea sp., is known to exist. Recent studies have raised controversy about their role in transmission of Fasciola spp. because of confusion in identification of the snail hosts. The aim of this study is, therefore, to clarify the identities of lymnaeid snails in Vietnam by a combination of morphological and molecular approaches. The molecular analyses using the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA clearly showed that lymnaeids in Vietnam include 3 species, Austropeplea viridis (morphologically identified as L. viridis), Radix auricularia (morphologically identified as L. swinhoei) and Radix rubiginosa (morphologically identified as Lymnaea sp.). R. rubiginosa is a new record for Vietnam. Among them, only A. viridis was found to be infected with Fasciola spp. These results provide a new insight into lymnaeid snails in Vietnam. Identification of lymnaeid snails in Vietnam and their role in the liver fluke transmission should be further investigated.
Animals ; Cluster Analysis ; DNA, Ribosomal Spacer/chemistry/genetics ; Fasciola/*isolation & purification ; Lymnaea/*anatomy & histology/genetics/*parasitology ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Vietnam

AIMTo synthesize novel derivatives of hydroxylbenzenedisulfonanilide with high insecticidal activity against the Fasciola hepatica.

METHODSo-(m-, p-) Chlorphenol were used to synthesize the title compounds by sulphonation and nucleiphilic-substitution reaction. The uncoupling activity (insecticidal activity) of these compounds were tested by determining the influence on mitochondrial respiration control ratio (RCR) and the variation of inorganic phosphate in oxidative phosphorylation (delta Pi).

RESULTSCompounds 1-14 are new compounds. The structures of the compounds were determined by IR, HNMR and elemental analysis. Most new compounds have relatively high uncoupling activities, especially compounds 3, 5, 6 and 9.

CONCLUSIONCompounds 3, 5, 6 and 9 will become novel fasciolicides and are worth further studying.

Anilides ; chemical synthesis ; chemistry ; pharmacology ; Animals ; Anthelmintics ; chemical synthesis ; chemistry ; pharmacology ; Fasciola hepatica ; drug effects ; Mitochondria, Liver ; physiology ; Molecular Structure ; Oxygen Consumption ; drug effects ; Sulfonamides ; chemical synthesis ; chemistry ; pharmacology

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

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

Fascioliasis is one of the public health problems in the world. Cysteine proteinases (CP) released by Fasciola gigantica play a key role in parasite feeding, migration through host tissues, and in immune evasion. There has been some evidence from several parasite systems that proteinases might have potential as protective antigens against parasitic infections. Cysteine proteinases were purified and tested in vaccine trials of sheep infected with the liver fluke. Multiple doses (2 mg of CP in Freund's adjuvant followed by 3 booster doses 1 mg each at 4 week intervals) were injected intramuscularly into sheep 1 week prior to infect orally with 300 F. gigantica metacercariae. All the sheep were humanely slaughtered 12 weeks after the first immunization. Changes in the worm burden, ova count, and humoral and cellular responses were evaluated. Significant reduction was observed in the worm burden (56.9%), bile egg count (70.7%), and fecel egg count (75.2%). Immunization with CP was also found to be associated with increases of total IgG, IgG1, and IgG2 (P<0.05). Data showed that the serum cytokine levels of pro-inflammatory cytokines, IL-12, IFN-gamma, and TNF-alpha, revealed significant decreases (P<0.05). However, the anti-inflammatory cytokine levels, IL-10, TGF-beta, and IL-6, showed significant increases (P<0.05). In conclusion, it has been found that CP released by F. gigantica are highly important candidates for a vaccine antigen because of their role in the fluke biology and host-parasite relationships.
Animals ; Antibodies, Helminth/immunology ; Cysteine Proteases/administration & dosage/*immunology/isolation & purification ; Cytokines/immunology ; Fasciola/chemistry/*enzymology/immunology ; Fasciola hepatica/immunology/physiology ; Fascioliasis/immunology/parasitology/*prevention & control ; Female ; Helminth Proteins/administration & dosage/*immunology/isolation & purification ; Humans ; Male ; Protective Agents/*administration & dosage/isolation & purification ; Sheep ; Vaccines/immunology

Although schistosomicidal drugs and other control measures exist, the advent of an efficacious vaccine remains the most potentially powerful means for controlling this disease. In this study, native fatty acid binding protein (FABP) from Fasciola gigantica was purified from the adult worm's crude extract by saturation with ammonium sulphate followed by separation on DEAE-Sephadex A-50 anion exchange chromatography and gel filtration using Sephacryl HR-100, respectively. CD1 mice were immunized with the purified, native F. gigantica FABP in Freund's adjuvant and challenged subcutaneously with 120 Schistosoma mansoni cercariae. Immunization of CD1 mice with F. gigantica FABP has induced heterologous protection against S. mansoni, evidenced by the significant reduction in mean worm burden (72.3%), liver and intestinal egg counts (81.3% and 80.8%, respectively), and hepatic granuloma counts (42%). Also, it elicited mixed IgG1/IgG2b immune responses with predominant IgG1 isotype, suggesting that native F. gigantica FABP is mediated by a mixed Th1/Th2 response. However, it failed to induce any significant differences in the oogram pattern or in the mean granuloma diameter. This indicated that native F. gigantica FABP could be a promising vaccine candidate against S. mansoni infection.
Animals ; Antibodies, Helminth/immunology ; Fasciola/*chemistry ; Fatty Acid-Binding Proteins/*administration & dosage/immunology/isolation & purification ; Female ; Helminth Proteins/*administration & dosage/immunology/isolation & purification ; Humans ; Immunization ; Mice ; Mice, Inbred Strains ; Schistosoma mansoni/immunology/*physiology ; Schistosomiasis mansoni/immunology/parasitology/*prevention & control