| methyl-directed desaturation of arachidonic to eicosapentaenoic acid in the fungus, saprolegnia parasitica. | the lipids of saprolegnia parasitica contain 5,8,11,14,17-eicosapentaenoic acid as major constituent. no other acid having (n-3) structure was detected, but 5,8,11,14-eicosatetraenoic (arachidonic) acid and its common precursors of (n-6) structure are present in significant amounts. during rapid growth of the organism, [1-14c]acetate was efficiently incorporated into fatty acids. arachidonic acid was labeled after 2 h to nearly the same extent as any precursor acid and 14c in eicosapentaenoic ac ... | 1979 | 454637 |
| mass mortality in cultured coho salmon (oncorhynchus kisutch) due to saprolegnia parasitica coker. | epizootics of saprolegniasis occurred in 20 to 60 g freshwater-cultured coho salmon (oncorhynchus kisutch) in miyagi prefecture, japan. cotton-like mycelia occurred on the body surface of infected fish, especially around the head, the adipose fin and the caudal fin, and aseptate hyphae occurred in the lesions. the hyphae also penetrated into the muscle and blood vessels. the isolated fungus was identified by asexual morphological characteristics as saprolegnia parasitica (syn. s. diclina type 1) ... | 1992 | 1474649 |
| enzymatic basis for protection of fish embryos by the fertilization envelope. | the mechanism by which the fertilization envelope (fe) is able to protect the embryo of fish until hatching is almost unknown, except for its function as a physical barrier. fe extract from activated or fertilized eggs of the fish salmo gairdneri was demonstrated to contain enzyme activities using an agar plate enzyme assay. the enzymes apparently active were carboxymethylcellulase (cellulase; ec 3.2.1.4), laminaranase (endo-1,3(4)-beta-glucanase; ec 3.2.1.6), carboxymethylchitinase (chitinase; ... | 1992 | 1547861 |
| lipids of selected molds grown for production of n-3 and n-6 polyunsaturated fatty acids. | the lipid classes and component fatty acids of seven fungi were examined. three marine fungi, thraustochytrium aureum, thraustochytrium roseum and schizochytrium aggregatum (grown at 30, 25 and 25 degrees c, respectively), produced less than 10% lipid but contained docosahexaenoic acid (dha) up to 30% and eicosapentaenoic acid (epa) up to 11% of the total fatty acids. mortierella alpinapeyron produced 38% oil containing solely n-6 polyunsaturated fatty acids (pufa) with arachidonic acid (aa) at ... | 1992 | 1608297 |
| effect of sublethal concentrations of four chemicals on susceptibility of juvenile rainbow trout (oncorhynchus mykiss) to saprolegniosis. | the effects of sublethal concentrations of a variety of chemicals on the susceptibility of rainbow trout (oncorhynchus mykiss) juveniles to saprolegnia parasitica infection was examined. sublethal concentrations of un-ionized ammonia (0.05 mg/liter) and nitrite (0.12 mg/liter) increased fish susceptibility after 10 days of exposure to the toxin, this increase being higher for ammonia (75% and 20% morbidity) than for nitrite (20% and 0% morbidity, respectively) with inoculum doses of 1.4 x 10(6) ... | 1991 | 1872610 |
| synthesis of some pyrazoline and isoxazolin derivatives as possible fungicides. | 1-acetyl/aroyl-3-methyl-4-substituted anilido-5-aryl pyrazolines and 3-methyl-4-substituted anilido-5-aryl isoxazolines were conveniently prepared from synthon, 4-aryl-3-substituted anilido but-3-en-2-ones in presence of hydrazine hydrate/hydrazides and hydroxylamine hydrochloride respectively. all the compounds have been assayed against cephalosporium sacchari and helminthosporium oryzae and found remarkably active. two species of aquatic fungi viz. saprolegnia parasitica and achlya orion respo ... | 1989 | 2637751 |
| [insemination of the salmon spawn by micromycetes at the fish-rearing farm "pushcha-voditsa"]. | fungi of 21 species attributed to 11 genera of three classes--oomycetes, zygomycetes, deuteromycetes--have been isolated from the surface of the salmo gairdneri rich. spawn and from water samples of incubation apparatuses of the fish-rearing farm "pushcha-voditsa" (the kiev region). among the revealed micromycetes only saprolegnia parasitica c o k e r is a fish parasite. most of isolates are imperfect fungi; they dominate among the hyphal forms in the mycobiota of fish and water and in natural w ... | 1989 | 2796785 |
| novel transformation of arachidonic acid in saprolegnia parasitica. | | 1987 | 2959120 |
| novel biological transformations of 15-ls-hydroperoxy-5,8,11,13-eicosatetraenoic acid. | [1-14c]arachidonic acid was incubated with homogenates of the fungus, saprolegnia parasitica. the products consisted of comparable amounts of two epoxy alcohols, 15-ls-hydroxy-11,12-epoxy-5cis,8cis,13trans- eicosatrienoic acid and 15-hydroxy-13,14-epoxy-5cis,8cis,11cis-eicosatrienoic acid. results of incubations carried out in the presence of nordihydroguaiaretic acid, 5,8,11,14-eicosatetraynoic acid, p-hydroxymercuribenzoate as well as glutathione peroxidase plus reduced glutathione demonstrate ... | 1986 | 3089290 |
| properties of the soluble arachidonic acid 15-lipoxygenase and 15-hydroperoxide isomerase from the oomycete saprolegnia parasitica. | the soluble hydroperoxide isomerase and 15-lipoxygenase activities were partially purified from the oomycete saprolegnia parasitica and some of their properties characterized. both enzymes co-eluted with a molecular weight of 145,000-150,000 on sephacryl s-300 chromatography. the enzyme activities also co-eluted on deae sephadex ion exchange chromatography and hydroxylapatite chromatography. both activities showed similar responses to ph and temperature. both enzymes showed parallel inhibition b ... | 1987 | 3685395 |
| prostaglandins or prostaglandin like substances are implicated in normal growth and development in oomycetes. | the prostaglandin synthesis inhibitors aspirin and indomethacin inhibit the growth of achlya caroliniana, a. ambisexualis and saprolegnia parasitica in a dose-related manner. in addition, the inhibitors cause the formation of a characteristic asterisk-shaped colony. this abnormal colony morphology does not appear to be dependent on medium composition, since three different nitrogen and five differentcarbon sources all support the abnormal growth in the presence of 0.1 mm indomethacin. the abnorm ... | 1985 | 3859894 |
| physiological parameters of growth in saprolegnia parasitica coker. | | 1972 | 5041291 |
| salinity tolerance of saprolegnia parasitica coker. | | 1971 | 5102595 |
| transformations of 5,8,11,14,17-eicosapentaenoic acid in human platelets. | 5,8,11,14,17-[1-14c]eicosapentaenoic acid was prepared biosynthetically from [1-14c]arachidonic acid using the fungus, saprolegnia parasitica. incubation of 5,8,11,14,17-[1-14c]eicosapentaenoic acid with suspensions of human platelets led to the formation of three labeled compounds which were identified as thromboxane b3 (2-5% yield), 12-hydroxy-5,8,10,14-heptadecatetraenoic acid (2-5% yield), and 12-hydroxy-5,8,10,14,17-eicosapentaenoic acid (7-59% yield). | 1980 | 6249377 |
| studies on parasitic watermolds some new host records for saprolegnia parasitica coker. | | 1982 | 7177165 |
| stereochemical aspects of fatty acid oxidation: hydroperoxide isomerases. | lipoxygenases catalyze dioxygenation of polyunsaturated fatty acids to produce fatty-acid hydroperoxides. the reaction involves initial stereospecific abstraction of a hydrogen atom from a bis-allylic methylene group followed by antarafacial attack by dioxygen at one of the terminal carbon atoms of the pentadienyl radical. 8(r)-dioxygenase, recently discovered in the fungus gaeumannomyces graminis, catalyzes formation of 8-hydroperoxy derivatives of linoleic and oleic acids by abstracting one hy ... | 1996 | 8901175 |
| the effects of used motor oil, silt, and the water mold saprolegnia parasitica on the growth and survival of mole salamanders (genus ambystoma). | amphibians appear to be declining worldwide. one cause of their decline may be used crankcase oil which leaks from motor vehicles and washes into ponds. once in ponds, the oil may either be directly toxic to amphibians, or may indirectly affect them by disrupting food chains. the effects of oil may also be compounded by naturally occurring materials in the water column such as silt. silt may interfere with respiration across gill surfaces. this study examined the effects of oil and silt on the g ... | 1997 | 9175503 |
| ultrastructure of fish cells involved in cellular defences against saprolegnia infections: evidence of non-leucocytic nature. | fish cells attached to hyphae were observed in brown trout salmo trutta l. infected with saprolegnia parasitica. earlier studies with light microscopy indicated that these cells were lymphocytes and neutrophils and that they were involved in the defence mechanisms against saprolegnia infections. however, using electron microscopy, we found these attached cells did not show leucocytic characteristics, but instead shared some ultrastructural features with filament-containing cells. the pressure of ... | 1998 | 9696627 |
| a saprolegnia parasitica challenge system for rainbow trout: assessment of pyceze as an anti-fungal agent for both fish and ova. | a reproducible saprolegnia parasitica spore delivery system was developed and demonstrated to be effective in providing a sustained spore challenge for up to 10 d. treatment of rainbow trout with slow-release intraperitoneal implants containing cortisol resulted in chronically elevated blood cortisol levels and rendered the fish susceptible to infection by s. parasitica when exposed to the spore challenge. sham-implanted fish were not susceptible to infection. bronopol (2-bromo-2-nitro-propane-1 ... | 1999 | 10399041 |
| synthesis and applications of stereospecifically (3)h-labeled arachidonic acids as mechanistic probes for lipoxygenase and cyclooxygenase catalysis. | stereospecifically (3)h-labeled substrates are useful tools in studying the mechanism of hydrogen abstractions involved in the oxygenation of polyunsaturated fatty acids. here, we describe modified methods for the synthesis of arachidonic acids labeled with a single chiral tritium on the methylene groups at carbons 10 or 13. the appropriate starting material is a ketooctadecanoic acid which is prepared from an unsaturated c18 fatty acid precursor or by total synthesis. the (3)h label is introduc ... | 2000 | 10933865 |
| synthesis of some n1-phenyl-n3-[2-aryl/aryloxymethyl-1,3,4-oxa(thia)diazol-2-yl]sulphonyl ureas as potential pesticides. | n1-phenyl-n3-aryl/aryloxymethyl[1,3,4-oxa(thia)diazol-2-yl]s ulphonyl ureas (4 and 7) were conveniently prepared from 2-aryl/aryloxymethyl- 1,3,4-oxa(thia)diazol-2-sulphonamide (3 and 6) and phenyl isothiocyanate. sulphonamides were synthesised by the reaction of 2-aryl/aryloxymethyl-1,3,4-oxa(thia)diazol-2-sulphonyl chlorides (2 and 5) with ammonia. all the compounds have been tested for fungicidal activity against the fungal species cephalosporium saccharii and helminthosporium oryzae. the two ... | 2000 | 11059098 |
| saprolegniosis in salmonids and their eggs in japan. | an epizootic of the fungal infection saprolegniosis that occurred in freshwater-cultured salmons and their eggs at some hatcheries in hokkaido (japan) was investigated. in almost all cases, the initial clinical sign was characterized by the growth of cotton-like mycelia on the fishs' body surface, especially the head, adipose fin, and caudal fin, but the mycelia were not visible to the naked eye in the internal organs. thirty-three strains isolated from lesions were classified in the genus sapro ... | 2001 | 11272500 |
| fungistatic activity of modified chitosans against saprolegnia parasitica. | five chemically modified chitosans were tested for their antifungal activities against saprolegnia parasitica by the radial growth assay in chitosan-bearing agar, and the fungal growth assay in chitosan-bearing broth. results indicated that methylpyrrolidinone chitosan, n-carboxymethyl chitosan and n-phosphonomethyl chitosan exerted effective fungistatic action against s. parasitica: in fact the radial growth was nil for 50 h at 20 degrees c, and the fungus was precipitated when the bacto ym bro ... | 2001 | 11749168 |
| haematological investigations on fishes infested with fungal growth. | considerable changes have been observed in the haematological parameters of labeo rohita, mystus cavasius, nandus nandus and puntius sarana infested with aphanomyces sp., saprolegnia parasitica, achlya prolifera and dictyuchus monosporus, respectively. substantial decline have been observed in the number of erythrocytes and lymphocytes. the number of granulocytes and monocytes were noticed significantly increased. the amount of haemoglobin has also been decreased drastically in all the cases. | 2001 | 12018597 |
| pumilio homologue from saprolegnia parasitica specifically expressed in undifferentiated spore cysts. | the expression of spore-specific marker transcripts at different stages of the asexual life cycle of saprolegnia parasitica was analyzed. one of the markers, designated puf1, was found to be expressed transiently upon each of several cycles of zoospore encystment and reemergence. the transcript is induced immediately upon zoospore encystment and is rapidly lost when a cyst is triggered to germinate. in nongerminating cysts, puf1 is maintained until a time point when the cysts can no longer be tr ... | 2002 | 12455976 |
| image analysis of hyphal morphogenesis in saprolegniaceae (oomycetes). | because of their wide range of apical morphology, several members of saprolegniaceous fungi (oomycetes) were chosen to examine concordance with the vesicle supply center (vsc) model of hyphal morphogenesis. two computer routines were devised to measure diameter changes over long stretches of hyphae and to test compatibility with the theoretical hyphoid shape, y = xcot(xv/n). in all four genera examined, the apex followed closely the contour described by the hyphoid equation; divergences became e ... | 2004 | 14761790 |
| morphological and biochemical alterations of oomycete fish pathogen saprolegnia parasitica as affected by salinity, ascorbic acid and their synergistic action. | vegetative growth of saprolegnia parasitica decreased by increasing the concentration of nacl and ascorbic acid. under these conditions, the morphological features of the vegetative hyphae were distinguishable from those used as controls. nacl and ascorbic acid in combination improved the tolerance of s. parasitica to high levels of salinity. sporangial formation, release and proliferation were very sensitive to even lower levels of salinity. for instance, at 0.03 m nacl sporangia formation was ... | 2005 | 15770449 |
| expressed sequence tags from the oomycete fish pathogen saprolegnia parasitica reveal putative virulence factors. | the oomycete saprolegnia parasitica is one of the most economically important fish pathogens. there is a dramatic recrudescence of saprolegnia infections in aquaculture since the use of the toxic organic dye malachite green was banned in 2002. little is known about the molecular mechanisms underlying pathogenicity in s. parasitica and other animal pathogenic oomycetes. in this study we used a genomics approach to gain a first insight into the transcriptome of s. parasitica. | 2005 | 16076392 |
| morphological and physiological characteristics of saprolegnia spp. strains pathogenic to atlantic salmon, salmo salar l. | seventeen strains of saprolegnia spp. were examined for morphological and physiological characteristics, and seven were examined for their pathogenicity to atlantic salmon, salmo salar l. two of the saprolegnia strains tested caused 89 and 31% cumulative mortality in challenged salmonids and were significantly more pathogenic than the other strains tested. the positive control (saprolegnia parasitica atcc 90213) caused 18% mortality, but this was not significantly higher than non-pathogenic stra ... | 2005 | 16159362 |
| effects of waterborne copper, cyanide, ammonia, and nitrite on stress parameters and changes in susceptibility to saprolegniosis in rainbow trout (oncorhynchus mykiss). | the effects of toxic exposures on the susceptibility of rainbow trout (oncorhynchus mykiss) to saprolegniosis were evaluated. fish were exposed to sublethal concentrations of copper (0.25 mg/liter), cyanide (0.07 mg/liter), ammonia (0.5 mg/liter), and nitrite (0.24 mg/liter) for 24 h. after exposure, the fish were challenged by saprolegnia parasitica (3.6 x 10(sup6) zoospores per liter) for 10 min. cortisol and cholesterol were used to indicate stress response. similar increases of cortisol were ... | 1995 | 16535039 |
| [health risks associated with the migration of atlantic salmon (salmo salar l.): an epidemiological surveillance programme in northern spain]. | the authors present the results of an epidemiological surveillance programme involving atlantic salmon (salmo salar) populations in north-eastern spain. the study investigates the risk factors critical in disease transmission, which include the presence of potentially pathogenic micro-organisms, the innate cell-mediated immune response of the salmon, and the potential interactions between the two. also taken into account are the biological and migratory cycles of these salmon populations. the re ... | 2005 | 16642759 |
| antibody response of brown trout salmo trutta injected with pathogenic saprolegnia parasitica antigenic extracts. | brown trout salmo trutta injected with antigenic extracts from a pathogenic isolate of saprolegnia parasitica developed specific antibodies that were detected by enzyme-linked immunosorbent assay (elisa), immunofluorescence (if) and western blotting (wb), but not by immunodiffusion (id). three groups of five 2 yr old brown trout were injected intraperitoneally with 3 different antigenic extracts: small hyphal fragments (hf) and soluble extracts from sonicated mycelia grown in medium with or with ... | 2007 | 17432039 |
| re-evaluation of the enigmatic species complex saprolegnia diclina-saprolegnia parasitica based on morphological, physiological and molecular data. | the phylogenetic relationships among isolates of the saprolegnia diclina-saprolegnia parasitica complex were investigated based on its rdna sequences, and correlated with morphological and physiological characters. the isolates studied belong to five phylogenetically separate clades. the majority of presumed parasitic isolates, mostly isolated from fish lesions, fell within a clade that comprises isolates which has been variously named as s. diclina type 1, s. parasitica, saprolegnia salmonis or ... | 2007 | 17446097 |
| reduction in vegetative growth of the water mold saprolegnia parasitica (coker) by humic substance of different qualities. | humic substances (hs) account for 50-80% of the dissolved organic matter in non-eutrophicated freshwater ecosystems. hs are not inert, but are taken up by and may interact with aquatic organisms. however, at present no information is available on the interaction of hs with fungi, for instance, the fish-pathogenous species saprolegnia parasitica. to fill this gap, we tested effects of hs on s. parasitica growth in-vitro using 25-500mgl(-1) carbon of hs on gy-agar. we investigated 20 hs including ... | 2007 | 17475348 |
| detection of 'long-haired' saprolegnia (s. parasitica) isolates using monoclonal antibodies. | the ability of five monoclonal antibodies (mabs) raised against a pathogenic saprolegnia parasitica isolate from brown trout to detect and differentiate between isolates with bundles of long hairs (s. parasitica) and other saprolegnia species was determined by means of an indirect immunofluorescence assay. four of the mabs used recognized some of the long-haired s. parasitica isolates but also cross-reacted with other saprolegnia species without bundles of hairs and with achlya sp. the other mab ... | 2007 | 17601716 |
| epidermal 'alarm substance' cells of fishes maintained by non-alarm functions: possible defence against pathogens, parasites and uvb radiation. | many fishes possess specialized epidermal cells that are ruptured by the teeth of predators, thus reliably indicating the presence of an actively foraging predator. understanding the evolution of these cells has intrigued evolutionary ecologists because the release of these alarm chemicals is not voluntary. here, we show that predation pressure does not influence alarm cell production in fishes. alarm cell production is stimulated by exposure to skin-penetrating pathogens (water moulds: saproleg ... | 2007 | 17686729 |
| [parasite fauna of the european river lamprey lampetra fluviatilis (l.) from lake onega]. | data on the parasite fauna of the adult european river lamprey lampetra fluviatilis (l.) from lake onega are reported. ten parasite species are found, including trematodes diplostomum petromyzifluviatilis and d. spathaceum (metacercariae), cestode proteocephalus longicollis, nematodes cucullanus truttae and raphidascaris acus, acanthocephalan echinorhynchus salmonis, ectoparasitic infusoria chilodonella hexastica, trichodina tenuidens, and trichodinella epizootica, and fungus saprolegnia parasit ... | 2007 | 17957959 |
| prevalence of serum antibodies against saprolegnia parasitica in wild and farmed brown trout salmo trutta. | the prevalence of serum antibodies against saprolegnia parasitica in wild and farmed brown trout salmo trutta from the province of le6n (nw spain) was studied by enzyme-linked immunosorbent assay (elisa). blood samples from healthy and saprolegnia-infected brown trout were collected over 2 yr with a seasonal periodicity (january, april, july and october) from a hatchery and river with frequent presence of saprolegniosis (river porma) and from a river in which the disease was rarely observed (riv ... | 2009 | 19301632 |
| identification of two gh18 chitinase family genes and their use as targets for detection of the crayfish-plague oomycete aphanomyces astaci. | the oomycete aphanomyces astaci is regarded as the causative agent of crayfish plague and represents an evident hazard for european crayfish species. native crayfish populations infected with this pathogen suffer up to 100% mortality. the existence of multiple transmission paths necessitates the development of a reliable, robust and efficient test to detect the pathogen. currently, a. astaci is diagnosed by a pcr-based assay that suffers from cross-reactivity to other species. we developed an al ... | 2009 | 19719847 |
| oridamycins a and b, anti-saprolegnia parasitica indolosesquiterpenes isolated from streptomyces sp. ks84. | oridamycins a (1) and b (2) were isolated from the fermentation broth of streptomyces sp. strain ks84 as selective anti-saprolegnia parasitica antibiotics. their structures were elucidated as pentacyclic indolosesquiterpenes by the combination of nmr and spectroscopic analyses. the absolute configuration of 1 was determined by roesy analyses after the advanced mosher analysis. compound 1 exhibited anti-s. parasitica activity with an mic value of 3.0 microg/ml, but was much less active against th ... | 2010 | 20369841 |
| the putative rxlr effector protein sphtp1 from the fish pathogenic oomycete saprolegnia parasitica is translocated into fish cells. | the fish pathogenic oomycete saprolegnia parasitica causes the disease saprolegniosis in salmonids and other freshwater fish, resulting in considerable economic losses in aquaculture. very little is known about the molecular and cellular mechanisms underlying the infection process of fish pathogenic oomycetes. in order to investigate the interaction in detail, an in vitro infection assay using an oncorhynchus mykiss (rainbow trout) cell line (rtg-2) was developed. in a zoospore/cyst cdna library ... | 2010 | 20659163 |
| chitin synthases from saprolegnia are involved in tip growth and represent a potential target for anti-oomycete drugs. | oomycetes represent some of the most devastating plant and animal pathogens. typical examples are phytophthora infestans, which causes potato and tomato late blight, and saprolegnia parasitica, responsible for fish diseases. despite the economical and environmental importance of oomycete diseases, their control is difficult, particularly in the aquaculture industry. carbohydrate synthases are vital for hyphal growth and represent interesting targets for tackling the pathogens. the existence of 2 ... | 2010 | 20865175 |
| entry of oomycete and fungal effectors into plant and animal host cells. | fungal and oomycete pathogens cause many destructive diseases of plants and important diseases of humans and other animals. fungal and oomycete plant pathogens secrete numerous effector proteins that can enter inside host cells to condition susceptibility. until recently it has been unknown if these effectors enter via pathogen-encoded translocons or via pathogen-independent mechanisms. here we review recent evidence that many fungal and oomycete effectors enter via receptor-mediated endocytosis ... | 2011 | 21819515 |
| Bacterial skin flora variation and in vitro inhibitory activity against Saprolegnia parasitica in brown and rainbow trout. | Variations in the number and diversity of bacteria from the skin of brown trout Salmo trutta L. and rainbow trout Oncorhynchus mykiss Walbaum were surveyed from different rivers and fish farms in northern Spain. In addition to determining bacterial populations in skin samples of healthy fish, bacterial populations were determined from skin lesions (of brown trout only) infected with Saprolegnia parasitica, the causal agent of saprolegniosis. Mean bacterial counts from skin lesions of brown trout ... | 2011 | 22013752 |
| development and reproduction of saprolegnia species in biofilms. | saprolegnia spp. can cause mortality and economic losses in freshwater fish and eggs. biofilm formation is generally regarded as a virulence factor, and biofilms can be an important cause of infection recurrence. evidence of persistent sources of saprolegnia infections on fish and eggs in fish farms support the assumption that saprolegnia spp. might be able to form biofilms. in this study, we aimed to test the ability of saprolegnia to form biofilms where it can survive, reproduce and resist dif ... | 2012 | 23313324 |
| the oxidosqualene cyclase from the oomycete saprolegnia parasitica synthesizes lanosterol as a single product. | the first committed step of sterol biosynthesis is the cyclisation of 2,3-oxidosqualene to form either lanosterol (la) or cycloartenol (ca). this is catalyzed by an oxidosqualene cyclase (osc). la and ca are subsequently converted into various sterols by a series of enzyme reactions. the specificity of the osc therefore determines the final composition of the end sterols of an organism. despite the functional importance of oscs, the determinants of their specificity are not well understood. in s ... | 2016 | 27881978 |
| host-targeting protein 1 (sphtp1) from the oomycete saprolegnia parasitica translocates specifically into fish cells in a tyrosine-o-sulphate-dependent manner. | the eukaryotic oomycetes, or water molds, contain several species that are devastating pathogens of plants and animals. during infection, oomycetes translocate effector proteins into host cells, where they interfere with host-defense responses. for several oomycete effectors (i.e., the rxlr-effectors) it has been shown that their n-terminal polypeptides are important for the delivery into the host. here we demonstrate that the putative rxlr-like effector, host-targeting protein 1 (sphtp1), from ... | 2012 | 22308362 |
| adhesion to brown trout skin mucus, antagonism against cyst adhesion and pathogenicity to rainbow trout of some inhibitory bacteria against saprolegnia parasitica . | biological control of saprolegniosis with bacteria might be an alternative to the use of chemical compounds. among criteria for the selection of such bacteria are their absence of pathogenicity to fish and their ability to prevent adhesion of the pathogen to the skin mucus. the pathogenicity to rainbow trout of 21 bacterial isolates with in vitro inhibitory activity against saprolegnia parasitica was studied. fifteen of the isolates, identified as aeromonas sobria, pantoea agglomerans, pseudomon ... | 2013 | 23670078 |
| fighting fish (betta splendens) bubble nests do not inhibit microbial growth. | some organisms produce antimicrobial substances in nesting foam to favorably manipulate the environment to which their developing offspring are exposed. we tested if fighting fish betta splendens foamy nest material, which is comprised of bubbles produced in the oral cavity of nesting males, has antimicrobial properties against a pathogenic bacteria (edwardsiella tarda), a nonpathogenic bacteria (escherichia coli), or a pathogenic oomycete (saprolegnia parasitica). we also tested if exposure to ... | 2012 | 22753365 |
| clotrimazole as a potent agent for treating the oomycete fish pathogen saprolegnia parasitica through inhibition of sterol 14α-demethylase (cyp51). | a candidate cyp51 gene encoding sterol 14α-demethylase from the fish oomycete pathogen saprolegnia parasitica (spcyp51) was identified based on conserved cyp51 residues among cyps in the genome. it was heterologously expressed in escherichia coli, purified, and characterized. lanosterol, eburicol, and obtusifoliol bound to purified spcyp51 with similar binding affinities (ks, 3 to 5 μm). eight pharmaceutical and six agricultural azole antifungal agents bound tightly to spcyp51, with posaconazole ... | 2014 | 25085484 |
| evaluation of the antifungal activity of zataria multiflora, geranium herbarium, and eucalyptus camaldolensis essential oils on saprolegnia parasitica-infected rainbow trout (oncorhynchus mykiss) eggs. | the purpose of the present study was to evaluate and assess the capability of zataria multiflora, geranium herbarium, and eucalyptus camaldolensis essential oils in treating saprolegnia parasitica-infected rainbow (oncorhynchus mykiss) trout eggs. a total of 150 infected eggs were collected and plated on glucose-pepton agar at 24°c for 2 weeks. the antifungal assay of essential oils against s. parasitica was determined by a macrodilution broth technique. the eggs were treated with essential oils ... | 2012 | 22690761 |
| in vitro passages impact on virulence of saprolegnia parasitica to atlantic salmon, salmo salar l. parr. | the effect of serial in vitro subculturing on three pathogenic strains of saprolegnia parasitica was investigated. the isolates were passed through atlantic salmon, salmo salar l. parr, and then re-isolated as single spore colonies. all strains caused infection. the isolate obtained from diseased fish served as a virulent reference culture and was designated 'ap' ('activated through passage'). successive subculturing was made by obtaining an inoculum from ap to produce the 2nd subculture and the ... | 2014 | 24117449 |
| novel core promoter elements in the oomycete pathogen phytophthora infestans and their influence on expression detected by genome-wide analysis. | the core promoter is the region flanking the transcription start site (tss) that directs formation of the pre-initiation complex. core promoters have been studied intensively in mammals and yeast, but not in more diverse eukaryotes. here we investigate core promoters in oomycetes, a group within the stramenopile kingdom that includes important plant and animal pathogens. prior studies of a small collection of genes proposed that oomycete core promoters contain a 16 to 19 nt motif bearing an init ... | 2013 | 23414203 |
| emerging oomycete threats to plants and animals. | oomycetes, or water moulds, are fungal-like organisms phylogenetically related to algae. they cause devastating diseases in both plants and animals. here, we describe seven oomycete species that are emerging or re-emerging threats to agriculture, horticulture, aquaculture and natural ecosystems. they include the plant pathogens phytophthora infestans, phytophthora palmivora, phytophthora ramorum, plasmopara obducens, and the animal pathogens aphanomyces invadans, saprolegnia parasitica and halio ... | 2016 | 28080985 |
| comparative analysis of sterol acquisition in the oomycetes saprolegnia parasitica and phytophthora infestans. | the oomycete class includes pathogens of animals and plants which are responsible for some of the most significant global losses in agriculture and aquaculture. there is a need to replace traditional chemical means of controlling oomycete growth with more targeted approaches, and the inhibition of sterol synthesis is one promising area. to better direct these efforts, we have studied sterol acquisition in two model organisms: the sterol-autotrophic saprolegnia parasitica, and the sterol-heterotr ... | 2017 | 28152045 |
| effect of β-glucan on the immune response of early stage of anabas testudineus (bloch) challenged with fungus saprolegnia parasitica. | the present study was carried out to study the effect of different dosages of β-glucan suspension on immune response and disease resistance in anabas testudineus spawns against a fungal pathogen saprolegnia parasitica. eight day old spawns were exposed for 3 h in four different dosages of β-glucan suspension in phosphate buffered saline at the rate of 0, 5, 10, 15 mg l(-1). the cell suspension of spawn was assayed for total protein, acid phosphate, lysozyme, bactericidal and nbt activity. the sp ... | 2013 | 23741642 |
| synthesis and evaluation of novel oxyalkylated derivatives of 2',4'-dihydroxychalcone as anti-oomycete agents against bronopol resistant strains of saprolegnia sp. | a series of novel oxyalkylchalcones substituted with alkyl groups were designed and synthesized, and the antioomycete activity of the series was evaluated in vitro against saprolegnia strains. all tested o-alkylchalcones were synthesized by means of nucleophilic substitution from the natural compound 2',4'-dihydroxychalcone (1) and the respective alkyl bromide. the natural chalcone (1) and 10 synthetic oxyalkylchalcones (2-11) were tested against saprolegnia parasitica and saprolegnia australis. ... | 2016 | 27556457 |
| cloning and identification of saprolmycin biosynthetic gene cluster from streptomyces sp. tk08046. | saprolmycins a-e are anti-saprolegnia parasitica antibiotics. to identify the gene cluster for saprolmycin biosynthesis in streptomyces sp. tk08046, polymerase chain reaction using aromatase and cyclase gene-specific primers was performed; the spr gene cluster, which codes for angucycline biosynthesis, was obtained from the strain. the cluster consists of 36 open reading frames, including minimal polyketide synthase, ketoreductase, aromatase, cyclase, oxygenase, and deoxy sugar biosynthetic gene ... | 2016 | 27316537 |
| eroded swimmeret syndrome in female crayfish pacifastacus leniusculus associated with aphanomyces astaci and fusarium spp. infections. | we describe a novel syndrome in crayfish, eroded swimmeret syndrome (ess), affecting wild female signal crayfish pacifastacus leniusculus. ess causes partial or total swimmeret erosion. we observed ess only in female signal crayfish larger than 40 mm carapace length, i.e. sexually mature and probably having carried eggs at least once. the eroded swimmerets were melanised, indicating a crayfish immune system response. we isolated fusarium tricinctum species complex (sc), f. sambucinum sc, saprole ... | 2015 | 25590772 |
| a putative serine protease, spssp1, from saprolegnia parasitica is recognised by sera of rainbow trout, oncorhynchus mykiss. | saprolegniosis, the disease caused by saprolegnia sp., results in considerable economic losses in aquaculture. current control methods are inadequate, as they are either largely ineffective or present environmental and fish health concerns. vaccination of fish presents an attractive alternative to these control methods. therefore we set out to identify suitable antigens that could help generate a fish vaccine against saprolegnia parasitica. unexpectedly, antibodies against s. parasitica were fou ... | 2014 | 25088077 |
| saprolmycins a-e, new angucycline antibiotics active against saprolegnia parasitica. | saprolmycins a-e, five new anti-saprolegnia parasitica antibiotics were isolated from the culture broth of streptomyces sp. strain tk08046. as determined using a combination of nmr and spectroscopic analyses, the structures of these compounds were elucidated as a new group of angucycline compounds closely related to saquayamycin. saprolmycin a and e exhibited potent anti-s. parasitica selective activities, with mic values of 3.9 and 7.8 ng ml(-1), respectively, but weak or no activity against fu ... | 2012 | 23093030 |
| hemi-synthesis and anti-oomycete activity of analogues of isocordoin. | an efficient synthesis of a series of 4'-oxyalkyl-isocordoin analogues (2-8) is reported for the first time. their structures were confirmed by ¹h-nmr, (13)c-nmr, and hrms. their anti-oomycete activity was evaluated by mycelium and spores inhibition assay against two selected pathogenic oomycetes strains: saprolegnia parasitica and saprolegnia australis. the entire series of isocordoin derivatives (except compound 7) showed high inhibitory activity against these oomycete strains. among them, com ... | 2017 | 28604594 |
| do fathead minnows, pimephales promelas rafinesque, alter their club cell investment in responses to variable risk of infection from saprolegnia? | fish in the superorder ostariophysi possess large epidermal club cells that release chemical cues warning nearby conspecifics of danger. despite the long-held assumption that such club cells evolved under the selective force of predation, recent studies demonstrated that predation has no effect on club cell investment. rather, club cells have an immune function and cell production may be stimulated by skin-penetrating pathogens and parasites. the current work investigates whether fathead minnows ... | 2012 | 22313366 |
| saprolegniosis in nile tilapia: identification, molecular characterization, and phylogenetic analysis of two novel pathogenic saprolegnia strains. | saprolegniosis is a fungal infection that leads to huge economic losses in tilapia aquaculture. saprolegnia spp. are usually implicated as the etiological agents, but their identification is sometimes troublesome and confusing. in this study, two saprolegnia strains (mans22 and mans33) were isolated from nile tilapia oreochromis niloticus suffering from saprolegniosis. both isolates were characterized morphologically and from internal transcribed spacer (its) sequence data. additionally, both st ... | 2017 | 28166463 |
| in vitro modulation of drimys winteri bark extract and the active compound polygodial on salmo salar immune genes after exposure to saprolegnia parasitica. | the rapid development of the aquaculture industry has global concerns with health management and control strategies to prevent and/or treat diseases and increase sustainability standards. saprolegniosis is a disease caused by saprolegnia parasitica, and is characterized by promoting an immunosuppression in the host. this study evaluated in vitro the extract and one active compound (polygodial) of drimys winteri, a chilean medicinal tree as a potential early immunostimulatory aid in saprolegniosi ... | 2016 | 27777106 |
| quantification of saprolegnia parasitica in river water using real-time quantitative pcr: from massive fish mortality to tap drinking water. | since 2010, the loue river (franche-comté, east of france) has been suffering from massive fish kills infested by saprolegnia parasitica. the river supplies inhabitants of the city of besançon in drinking water, raising the question of a potential risk through both water consumption and use. we developed a real-time quantitative pcr (qpcr) to quantify s. parasitica in the loue river as well as in the drinking water. a weak spatial trend is suggested with greater quantities of s. parasitica obser ... | 2017 | 27750437 |
| feeding pyridoxine prevents saprolegnia parasitica infection in fish labeo rohita. | a 60-day experiment was carried out to delineate the role of dietary pyridoxine (dp) in labeo rohita fingerlings in modulating immunity and prevention of fungal infection. two hundred and seventy fingerlings were randomly distributed into three treatments in triplicates. three iso-caloric and iso-nitrogenous purified diets were prepared with graded levels of pyridoxine. three experimental groups were c (0.0% dp), t1 (0.01% dp) and t2 (0.02% dp). the role of dietary pyridoxine in modulating immun ... | 2016 | 27670085 |
| analysis of saprolegnia parasitica transcriptome following treatment with copper sulfate. | massive infection caused by oomycete fungus saprolegnia parasitica is detrimental to freshwater fish. recently, we showed that copper sulfate demonstrated good efficacy for controlling s. parasitica infection in grass carp. in this study, we investigated the mechanism of inhibition of s. parasitica growth by copper sulfate by analyzing the transcriptome of copper sulfate-treated s. parasitica. to examine the mechanism of copper sulfate inhibiting s. parasitica, we utilized rna-seq technology to ... | 2016 | 26895329 |
| computational studies of the binding profile of phosphoinositide ptdins (3,4,5) p₃ with the pleckstrin homology domain of an oomycete cellulose synthase. | saprolegnia monoica is a model organism to investigate saprolegnia parasitica, an important oomycete which causes considerable loss in aquaculture every year. s. monoica contains cellulose synthases vital for oomycete growth. however, the molecular mechanism of the cellulose biosynthesis process in the oomycete growth is still poorly understood. some cellulose synthases of s. monoica, such as smcesa2, are found to contain a plecsktrin homology (ph) domain, which is a protein module widely found ... | 2016 | 26857031 |
| inhibition of dioscin on saprolegnia in vitro. | as one of the most serious pathogens in the freshwater aquatic environment, saprolegnia can induce a high mortality rate during the fish egg incubation period. this study investigated the anti-saprolegnia activity of a total of 108 plants on saprolegnia parasitica in vitro and dioscorea collettii was selected for further studies. by loading on an open silica gel column and eluting with petroleum ether-ethyl acetate-methanol, dioscin (c45h72o16) was isolated from d. collettii. saprolegnia parasit ... | 2015 | 26472687 |
| chemical characterization and anti-oomycete activity of laureliopsis philippianna essential oils against saprolegnia parasitica and s. australis. | laureliopsis philippiana (looser) r. schodde (monimiaceae) is a native tree widespread in the forest areas in the south of chile and argentina, known for its medicinal properties and excellent wood. the aim of this study was to evaluate the chemical composition of l. philippiana leaf and bark essential oils (eos) using gas chromatography-mass spectrometry (gc-ms), and to quantify its anti-oomycete activity, specifically against saprolegnia parasitica and s. australis. only six components were id ... | 2015 | 25951001 |
| species composition of the genus saprolegnia in fin fish aquaculture environments, as determined by nucleotide sequence analysis of the nuclear rdna its regions. | the its region of the rdna gene was compared for saprolegnia spp. in order to improve our understanding of nucleotide sequence variability within and between species of this genus, determine species composition in canadian fin fish aquaculture facilities, and to assess the utility of its sequence variability in genetic marker development. from a collection of more than 400 field isolates, its region nucleotide sequences were studied and it was determined that there was sufficient consistent inte ... | 2015 | 25601147 |
| new approaches for controlling saprolegnia parasitica, the causal agent of a devastating fish disease. | pathogenic oomycetes have the ability to infect a wide range of plant and animal hosts and are responsible for a number of economically important diseases. saprolegniasis, a disease affecting fish eggs and juvenile fish in hatcheries worldwide, is caused by the pathogenic oomycete saprolegnia parasitica. this disease presents as greyish-white patches of filamentous mycelium on the body or fins of fish and is associated with tissue damage leading to death of the animal. traditionally, saprolegnia ... | 2014 | 27073602 |
| role of pathogen-derived cell wall carbohydrates and prostaglandin e2 in immune response and suppression of fish immunity by the oomycete saprolegnia parasitica. | saprolegnia parasitica is a freshwater oomycete that is capable of infecting several species of fin fish. saprolegniosis, the disease caused by this microbe, has a substantial impact on atlantic salmon aquaculture. no sustainable treatment against saprolegniosis is available, and little is known regarding the host response. in this study, we examined the immune response of atlantic salmon to s. parasitica infection and to its cell wall carbohydrates. saprolegnia triggers a strong inflammatory re ... | 2014 | 25114122 |
| functional characterization of a tyrosinase gene from the oomycete saprolegnia parasitica by rnai silencing. | here we describe the first application of transient gene silencing in saprolegnia parasitica, a pathogenic oomycete that infects a wide range of fish, amphibians, and crustaceans. a gene encoding a putative tyrosinase from s. parasitica, sptyr, was selected to investigate the suitability of rna-interference (rnai) to functionally characterize genes of this economically important pathogen. tyrosinase is a mono-oxygenase enzyme that catalyses the o-hydroxylation of monophenols and subsequent oxida ... | 2014 | 25088076 |
| seasonal and sex-related variations in serum steroid hormone levels in wild and farmed brown trout salmo trutta l. in the north-west of spain. | serum steroid profiles were investigated in order to evaluate the potential use of circulating sex steroid levels as a tool for sex identification in brown trout. changes in the serum concentrations of testosterone (t), progesterone (p), 17-β-estradiol (e2), and cortisol (f) in wild and farmed mature female and male brown trout, salmo trutta l., were measured in each season (january, may, july, and october) in six rivers and four hatcheries located in the north-west of spain. serum cortisol leve ... | 2013 | 24334846 |
| distinctive expansion of potential virulence genes in the genome of the oomycete fish pathogen saprolegnia parasitica. | oomycetes in the class saprolegniomycetidae of the eukaryotic kingdom stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. we have sequenced the 63 mb genome of the fresh water fish pathogen, saprolegnia parasitica. approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. comparison of s. parasitica with ... | 2013 | 23785293 |
| immune gene expression in trout cell lines infected with the fish pathogenic oomycete saprolegnia parasitica. | the oomycete saprolegnia parasitica causes significant losses in the aquaculture industry, mainly affecting salmon, trout and catfish. since the ban of malachite green, effective control measures are currently not available prompting a re-evaluation of the potential for immunological intervention. in this study, the immune response of salmonid cells is investigated at the transcript level, by analysis of a large set of immune response genes in four different rainbow trout cell lines (rtg-2, rtgi ... | 2012 | 22522286 |
| functional characterization of the pleckstrin homology domain of a cellulose synthase from the oomycete saprolegnia monoica. | some oomycetes, for instance saprolegnia parasitica, are severe fish pathogens that cause important economic losses worldwide. cellulose biosynthesis is a vital process for this class of microorganisms, but the corresponding molecular mechanisms are poorly understood. of all cellulose synthesizing enzymes known, only some oomycete cellulose synthases contain a pleckstrin homology (ph) domain. some human ph domains bind specifically to phosphoinositides, but most ph domains bind phospholipids in ... | 2012 | 22226909 |
| effects of fluconazole based medicated feed on haemato-immunological responses and resistance of labeo rohita against saprolegnia parasitica. | fluconazole (flz) is a new azole antifungal drug having no earlier record of its utilization for the treatment of fish diseases. a 55-days experiment was carried out to delineate the role of flz based medicated feed on haemato-immunological responses and prevention of fungal infection in labeo rohita fingerlings. three hundred and sixty fingerlings were randomly distributed into four experimental groups in triplicates. four iso-caloric and iso-nitrogenous purified medicated feeds were prepared w ... | 2017 | 28964864 |
| specialized attachment structure of the fish pathogenic oomycete saprolegnia parasitica. | the secondary cysts of the fish pathogen oomycete saprolegnia parasitica possess bundles of long hooked hairs that are characteristic to this economically important pathogenic species. few studies have been carried out on elucidating their specific role in the s. parasitica life cycle and the role they may have in the infection process. we show here their function by employing several strategies that focus on descriptive, developmental and predictive approaches. the strength of attachment of the ... | 2018 | 29342156 |