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effect of macrophages and serum of fish susceptible or resistant to epizootic ulcerative syndrome (eus) on the eus pathogen, aphanomyces invadans.epizootic ulcerative syndrome (eus) is one of the most destructive diseases of fresh and brackish water farmed and wild fish in the asia-pacific region. the in vitro germination and growth of the propagules of the eus pathogen, aphanomyces invadans (= a. piscicida), were assessed in the presence of the head-kidney macrophages, serum, and serum heated to inactivate complement proteins, of three eus-susceptible and one resistant fish species. the susceptible species were: striped snakehead (channa ...200111592585
factors influencing the sporulation and cyst formation of aphanomyces invadans, etiological agent of ulcerative mycosis in atlantic menhaden, brevoortia tyrannus.oomycete infections caused by aphanomyces invadans occur in freshwater and estuarine fishes around the world. along the east coast of the usa, skin ulcers caused by a. invadans are prevalent in atlantic menhaden, brevoortia tyrannus. from laboratory observations low salinities appear crucial to transmission of the pathogen. to better understand aspects of transmission, we characterized sporulation and cyst formation of secondary zoospores of two isolates of a. invadans at different salinities an ...200516392244
molecular assays for detecting aphanomyces invadans in ulcerative mycotic fish lesions.the pathogenic oomycete aphanomyces invadans is the primary etiological agent in ulcerative mycosis, an ulcerative skin disease caused by a fungus-like agent of wild and cultured fish. we developed sensitive pcr and fluorescent peptide nucleic acid in situ hybridization (fish) assays to detect a. invadans. laboratory-challenged killifish (fundulus heteroclitus) were first tested to optimize and validate the assays. skin ulcers of atlantic menhaden (brevoortia tyrannus) from populations found in ...200616461710
pathogenicity studies with the fungi aphanomyces invadans, achlya bisexualis, and phialemonium dimorphosporum: induction of skin ulcers in striped mullet.based on isolations from naturally infected fish in florida, we investigated the role of the fungi aphanomyces invadans, achlya bisexualis, and phialemonium dimorphosporum in the etiology of ulcerative mycosis (um) in striped mullet mugil cephalus. we injected healthy striped mullet subcutaneously with secondary zoospores of four oomycete isolates: two concentrations (50 and 115 zoospores/ml) of sjr (an endemic isolate of aphanomyces invadans in american shad alosa sapidissima from the st. johns ...200718236631
experimental infection and detection of aphanomyces invadans in european catfish, rainbow trout and european eel.european catfish silurus glanis, european eel anguilla anguilla and rainbow trout oncorhynchus mykiss were challenged by intramuscular injection of zoospores of aphanomyces invadans, the oomycete associated with epizootic ulcerative syndrome (eus). the tropical three-spot gourami trichogaster trichopterus is known to be highly susceptible and was used as a positive control. european catfish were highly susceptible and rainbow trout had moderate to low susceptibility, whereas eels appeared largel ...200819244971
are all koi ulcer cases associated with infection by atypical aeromonas salmonicida? polymerase chain reaction assays of koi carp skin swabs submitted by hobbyists.infection by atypical aeromonas salmonicida is regarded as the cause of ulcer disease (kud) in koi carp cyprinus carpio and goldfish carassius auratus. however, other causes--including parasites, viral infection, and fungi--have been proposed. in our diagnostic work, we often fail to isolate a. salmonicida even when clear clinical signs of kud are present. this failure may be because these fastidious and slow-growing bacteria are difficult to isolate in culture or because the bacteria are not ac ...200919873831
epizootic ulcerative syndrome: exotic fish disease threatens africa's aquatic ecosystems.in late 2006 an unusual ulcerative condition in wild fish was reported for the first time in africa from the chobe and upper zambezi rivers in botswana and namibia. concern increased with subsistence fishermen reporting large numbers of ulcerated fish in their catches. in april 2007 the condition was confirmed as an outbreak of epizootic ulcerative syndrome (eus). the causative agent, aphanomyces invadans, is a pathogenic water mould of fish that shows little host specificity. ulcers follow infe ...201223327133
phylogenetic relationships among plant and animal parasites, and saprotrophs in aphanomyces (oomycetes).molecular phylogenetic relationships among 12 species of aphanomyces de bary (oomycetes) were analyzed based on 108 its sequences of nuclear rdna. sequences used in the analyses belonged to the major species currently available in pure culture and genbank. bayesian, maximum likelihood, and maximum parsimony analyses support that aphanomyces constitutes a monophyletic group. three independent lineages were found: (i) plant parasitic, (ii) animal parasitic, and (iii) saprotrophic or opportunistic ...200919236935
epizootic ulcerative syndrome affecting fish in the zambezi river system in southern africa.in late 2006, diseased fish of a variety of species began to appear in the chobe and upper zambezi rivers in southern africa. in april 2007, investigations showed that the levels of pesticides and heavy metals in the tissues of the fish were very low, discounting pollution as an underlying cause for the disease. however, histological evidence showed that the disease closely resembled the epizootic ulcerative syndrome caused by the oomycete aphanomyces invadans, a serious aquatic pathogen that ha ...200819029110
aphanomyces invadans and ulcerative mycosis in estuarine and freshwater fish in florida.in the spring of 1998, the florida fish and wildlife research institute received numerous reports of lesioned or ulcerated fish primarily from the st. lucie estuary on the southeast coast of florida, an area known since the late 1970s for lesions of the ulcerative mycosis (um) type. from these and archived reports, as well as others received from different areas of florida, we documented that diseased specimens had randomly distributed skin ulcers (usually reddened or hemorrhagic) with raised ir ...200718236628
molecular characterization of the fish-pathogenic fungus aphanomyces invadans.aphanomyces invadans (saprolegniaceae) is a peronosporomycete fungus associated with the serious fish disease, epizootic ulcerative syndrome (eus), also known as mycotic granulomatosis. in this study, interspecific relationships were examined between a. invadans isolates and other aquatic animal pathogenic saprolegniaceae, and saprophytic saprolegniaceae from eus-affected areas. restriction fragment length polymorphisms and sequences of ribosomal dna confirmed that a. invadans is distinct from a ...200312962235
immunofluorescence of the epizootic ulcerative syndrome pathogen, aphanomyces invadans, using a monoclonal antibody.a monoclonal antibody (mab), designated 3gjc9, was raised against a protein antigen of aphanomyces invadans, the oomycete pathogen that causes epizootic ulcerative syndrome (eus). the antigen was expressed on the surface of hyphae and secreted extracellularly. mab 3gjc9 did not cross-react with other oomycete or fungal pathogens of fish, although it did react to the crayfish plague pathogen a. astaci. the mab was used for immunofluorescent staining on histological sections of fish infected with ...200312887259
infectivity and pathogenicity of the oomycete aphanomyces invadans in atlantic menhaden brevoortia tyrannus.atlantic menhaden brevoortia tyrannus develop characteristic skin ulcers in response to infection by the oomycete aphanomyces invadans. to investigate pathogenicity, we conducted a dose response study. juvenile menhaden were inoculated subcutaneously with 0, 1, 5, 10, 100, and 500 secondary zoospores per fish and monitored for 37 d post-injection (p.i.). survival rates declined with increasing zoospore dose, with significantly different survivorship curves for the different doses. moribund and d ...200312747639
skin ulcers in estuarine fishes: a comparative pathological evaluation of wild and laboratory-exposed fish.the toxic dinoflagellate pfiesteria piscicida steidinger & burkholder has recently been implicated as the etiologic agent of acute mass mortalities and skin ulcers in menhaden, brevoortia tyrannus, and other fishes from mid-atlantic u.s. estuaries. however, evidence for this association is largely circumstantial and controversial. we exposed tilapia (oreochromis spp.) to pfiesteria shumwayae glasgow & burkholder (identification based on scanning electron microscopy and molecular analyses) and co ...200111677176
review of biological factors relevant to import risk assessments for epizootic ulcerative syndrome (aphanomyces invadans).epizootic ulcerative syndrome (eus) is a disease affecting both wild and farmed fish in freshwater and estuarine environments. after it was first described in japan in 1971, the disease has spread widely across asia and to some regions of australia, north america and africa. in asia and africa, the spread of the disease has substantially affected livelihoods of fish farmers and fishermen. no reports are yet published showing the presence of the disease in europe or south america. given its epizo ...201121733135
Immune responses and protection in catla (Catla catla) vaccinated against epizootic ulcerative syndrome.Three different antigenic preparations from the epizootic ulcerative syndrome (EUS) pathogen Aphanomyces invadans were evaluated as vaccine candidate in catla (Catla catla). Anti-catla enzyme immunoconjugate was prepared after isolating catla immunoglobulin and raising hyperimmune sera against it, in rabbit. Three antigens namely, fungal extract (FE), fungal extract mixed with Freund's incomplete adjuvant (FIA) in a 1:1 (v/v) ratio (FE + A) and extra cellular product (ECP) were prepared and thre ...201222155323
epizootic ulcerative syndrome caused by aphanomyces invadans in captive bullseye snakehead channa marulius collected from south florida, usa.epizootic ulcerative syndrome (eus) caused by the oomycete aphanomyces invadans is an invasive, opportunistic disease of both freshwater and estuarine fishes. originally documented as the cause of mycotic granulomatosis of ornamental fishes in japan and as the cause of eus of fishes in southeast asia and australia, this pathogen is also present in estuaries and freshwater bodies of the atlantic and gulf coasts of the usa. we describe a mass mortality event of 343 captive juvenile bullseye snakeh ...201020225678
dermatitis, branchitis and mortality in empire gudgeon hypseleotris compressa exposed naturally to runoff from acid sulfate soils.severe dermatitis and branchitis are described in a wild population of empire gudgeon hypseleotris compressa, an australian eleotrid, exposed naturally to runoff from acid sulfate soils (ass) in a drained estuarine embayment in eastern australia. after at least 2 d exposure to ph < 4, and up to 7 d exposure to ph < 6, approximately 50% of the fish sampled had moderate to severe diffuse epidermal hyperplasia, usually at scale margins, and scattered areas of moderate to severe, focal to locally ex ...200515819440
infection experiments with aphanomyces invadans in four species of estuarine fish.along the eastern seaboard of the us, atlantic menhaden, brevoortia tyrannus, develop characteristic ulcerative lesions, a condition termed ulcerative mycosis. these lesions are identical to those seen across asia in fish affected by epizootic ulcerative syndrome, a condition caused by the fungus-like oomycete aphanomyces invadans. young-of-the-year menhaden inhabiting estuarine environments are the primary species affected in the usa and little is known about the factors involved in the initiat ...200415139907
characterization of aphanomyces invadans isolates using pyrolysis mass spectrometry (pyms).twenty-one isolates of aphanomyces invadans, the fungal pathogen associated with the asian fish disease epizootic ulcerative syndrome (eus), were compared with other oomycete fungi in terms of their pyrolysis mass spectrometry (pvms) profiles. canonical variate analysis (cva) of the pyrolysis mass spectra distinguished the aphanomyces species from a wide scatter of achlya and saprolegnia isolates. further cva and hierarchal cluster analysis (hca) separated the aphanomyces species into two main g ...200111766103
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