10 research outputs found

    Diphyllobothrium dendriticum (Cestoda: Pseudophyllidea) from Tasmania

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    Adult cestodes recovered from the small intestines of water rats (Hydromys chrysogaster) in Northern Tasmania were identified, on the basis of their morphology and the developmental requirements of their coracidia, as non-marine members of the genus Diphyllobothrium. The exact taxonomic position of this diphyllobothriid is not known. It differs in some respects from Stephens' (1908) description of a parasite (Diphyllobothrium parvum) obtained from the same locality, but could not be clearly differentiated from D. dendriticum. Thus, until more information is available about the full life cycle of this parasite, we consider it to be D. dendriticum. ac]1986072

    Resistance of Trichostrongylus colubriformis to levamisole and morantel: Differences in relation to selection history

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    Two field strains of Trichostrongylus colubriformis were tested by in vitro and in vivo methods for resistance to morantel, levamisole and thiabendazole and compared with an anthelmintic-naive laboratory-passaged strain (McM). One field strain (TAS) was isolated from a dairy goat herd which had experienced severe helminthiasis despite intensive anthelmintic usage. The other (BCK) was isolated from sheep which had been treated solely with levamisole over a 6-year period. The BCK strain had very high levels of both levamisole and morantel resistance. In contrast the TAS strain was resistant to morantel but highly susceptible to levamisole. This finding is contrary to the expectation that selection with morantel automatically confers resistance to levamisole, the converse of which was shown to apply in the BCK strain. Although the TAS strain was exposed to levamisole prior to isolation, examination of the drug's pharmacokinetics in goats indicated that it exerted little if any anthelmintic effect, and therefore selection pressure, on the parasite population. This study suggests that the mechanism of levamisole resistance covers a wide spectrum, and embraces that for morantel. It also suggests that in order to conserve the effectiveness of the levamisole/morantel group of broad spectrum anthelmintics, morantel should be used to the exclusion of levamisole until resistance is detected, at which time levamisole may be introduced to re-establish high levels of control

    Phenolics, sugars, antimicrobial and free-radical-scavenging Activities of Melicoccus bijugatus Jacq. fruits from the Dominican Republic and Florida

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    Edible fruits of the native South American tree Melicoccus bijugatus Jacq. are consumed fresh or in traditional food, drink and medicinal preparations. Some therapeutic effects of these fruits may be due to phenolics and sugars. Aqueous acetone, methanol or ethanol tissue extracts of different cultivars or collections of M. bijugatus fruits from the Dominican Republic and Florida were analyzed for total phenolics and free radical scavenging activity by UV-vis spectroscopy, sugars by gas chromatography, and antimicrobial activity by the disc diffusion assay. Total phenolics and free radical scavenging activities ranked: seed coat > embryo > pulp extracts. Montgomery cultivar fruits had the highest total phenolics. For sugars: pulp > embryo and highest in Punta Cana fruit pulp. In all extracts: sucrose > glucose and fructose. Glucose:fructose ratios were 1:1 (pulp) and 0.2:1 (embryo). Pulp extracts had dose-response antibacterial activity and pulp and embryo extracts had antifungal activity against one yeast species. Phenolics and sugars were confirmed with thin-layer chromatography and nuclear magnetic resonance. Sugar-free pulp fractions containing phenolics had slightly more antimicrobial activity than H2O-soluble pulp fractions with sugars. Results indicate M. bijugatus fruits contain phenolics, sugars and other H2O-soluble compounds consistent with therapeutic uses

    Characterisation of phenolics by LC–UV/Vis, LC–MS/MS and sugars by GC in Melicoccus bijugatus Jacq. ‘Montgomery’ fruits

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    Fruits of the native South American tree Melicoccus bijugatus Jacq. (Sapindaceae) are consumed for both dietary and medicinal purposes, but limited information is available about the phytochemistry and health value of M. bijugatus fruits. Fruit tissues of the Florida Montgomery cultivar were assessed for sugars, using gas chromatography, and for total phenolics, using UV spectroscopy. Reverse-phase high performance liquid chromatography (HPLC) fingerprints of crude methanolic pulp, embryo and seed coat extracts were obtained at 280 nm. Phenolics were characterised by both HPLC–UV/Vis analysis and HPLC electrospray ionisation tandem mass spectrometry. Major sugars detected in the pulp and embryo extracts were sucrose, followed by glucose and fructose. The glucose:fructose ratio was 1:1 in the pulp and 0.1:1 in the embryo. Total phenolic concentrations of the fruit tissues were in the order: seed coat > embryo > pulp. Phenolic acids were identified mostly in pulp tissues. Phenolic acids, flavonoids, procyanidins and catechins were identified in embryo tissues, and higher molecular weight procyanidins were identified in seed coat tissues. This study provides new information about the phytochemistry and the potential health value of the Montgomery cultivar M. bijugatus fruit tissues

    Notocotylidae (Digenea) from the Australian water rat Hydromys chrysogaster Geoffroy, 1804 (Muridae)

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    Notocotylus johnstoni n. sp., N. imbricatus (Looss, 1893) Szidat, 1935 and Catatropis nicolli n. sp. are described from the large intestine and caecum of the Australian water rat Hydromys chrysogaster (Rodentia: Muridae). The water rat is the only known mammalian host of notocotylids in Australia. N. imbricatus, recorded from Tasmania, is a cosmopolitan species which elsewhere uses birds and bithyniid snails as definitive and intermediate hosts respectively. In Tasmania bithyniid snails are unknown and the only known definitive host is a mammal. In view of this it is possible that the material examined represents a species distinct from N. imbricatus. Catatropis gallinulae Johnston, 1928 is found to have three rows of ventral papillae and thus to belong to the genus Notocotylus. The new combination Notocotylus gallinulae (Johnston, 1928) is a senior homonym of Notocotylus gallinulae El-Naffar & Khalifa, 1983 which is replaced with Notocotylus elnaffari nom. nov

    The brachylaimidae (Trematoda: Digenea) of Australian native mammals and birds, including descriptions of Dasyurotrema n. g. and four new species of Brachylaima

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    The Brachylaimidae of Australian native animals are revised. Brachylaima dasyuri (Johnston, 1913) is redescribed from Dasyurus viverrinus, Phascogale tapoatafa and Isoodon macrourus. B. simile (Johnston, 1913) is removed from synonymy with B. dasyuri, reinstated as a valid species and redescribed from Perameles nasuta, Isoodon obesulus and Antechinus stuartii. B. antechini Peisley & Howell, 1975 is reduced to synonymy with B. simile. B. brindabellensis n. sp. is described from Rattus fuscipes. B. walterae n. sp. is described from Antechinus swainsonii and A. stuartii. B. delecta n. sp. is described from Antechinus flavipes. B. sandarsae n. sp. is described from Antechinus godmani. B. pulchellum (Johnston, 1917) is redescribed from Leucosarcia melanoleuca. An unnamed Brachylaima species is described from Isoodon macrourus. New host records are Brachylaima dasyuri from Phascogale tapoatafa and B. simile from Perameles nasuta. Dasyurotrema mascomai n. g., n. sp. is described from Antechinus swainsonii. The new genus is placed in the Panopistinae. It differs from the existing genera by having a single loop of the uterus passing anterior to the ventral sucker and the genital pore posterior to the posterior testis but still distinctly ventral. A second species of Dasyurotrema is recorded, but not described, from Antechinus stuartii. Brachylaimid metacercariae are described from Rhytida capillacea, Helicarion virens, H. mastersi and Vercularion strangei. In no case was a host species found to harbour more than one species from any brachylaimid genus at a single geographical site
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