Oomycete fungi associated with ulcerative mycosis in menhaden, <i>Brevoortia tyrannus</i> (Latrobe)

Noga, Edward J.; Dykstra, Michael J.

doi:10.1111/j.1365-2761.1986.tb00978.x

Cited by 77 publications

(48 citation statements)

References 5 publications

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“…and Branchimyces sp., the fluorescence of the hyphae was no stronger than the background. However, Section 82-1240 from an Atlantic menhaden Brevoortia tyrannus infected with ulcerative mycosis showed strong fluorescence of the hyphae in a manner identical to the sections of EUS-infected fish, supporting the conclusion of Blazer et al (1999Blazer et al ( , 2002 and Kiryu et al (2002) that the large-scale fish mortalities that have been reported from the SE USA since 1984 Photographed at 40× magnification; scale bars indicate 50 µm (Noga & Dykstra 1986), dubbed ulcerative mycosis, are in fact caused by Aphanomyces invadans. Sections of crayfish infected with Aphanomyces astaci did not induce as strong a reaction as sections of EUS-infected fish, but the hyphae fluoresced strongly after a third reaction cycle.…”

Section: Staining Of Fixed Germlings By Immunofluorescence Antibody Tsupporting

confidence: 71%

Immunofluorescence of the epizootic ulcerative syndrome pathogen, Aphanomyces invadans, using a monoclonal antibody

Miles¹,

Thompson²,

Lilley³

et al. 2003

Dis. Aquat. Org.

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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 EUS, and was found to be more sensitive than conventional staining methods for detecting A. invadans. It thus has utility in confirming the case definition of EUS. It also revealed very small filamentous structures, the significance of which is unclear, but they may represent an early stage of infection, thus allowing earlier detection of the disease, since they are not detected using conventional staining methods. produced by sporulation, and diluting the pond water containing them in an equal volume of glucosepeptone broth media containing 100 mM calcium chloride to stimulate germination (Deacon & Saxena 1998). They were incubated overnight at 24°C and collected by centrifuging at 3000 × g for 20 min. The germlings were prepared for experimental use by fixing in formaldehyde as described by Burr (1991), and after a final wash with phosphate buffered saline at pH 7.4 (PBS), the germlings were resuspended in PBS and the concentration of the suspension determined by counting the germlings in a haemocytometer.Soluble antigens were collected after disruption of the germlings by shaking with 0.5 mm silicon beads for 160 s in a bead shaker (Biospec Products). The concentration of the soluble antigen was assessed spectrophotometrically.Preparation of monoclonal antibodies: The MAbs were prepared after Adams et al. (1995). Three BALB/c mice received 3 × 100 µl intraperitoneal injections of soluble antigen prepared from germlings of Aphanomyces invadans isolate PA8 over a 60 d period. . The last immunisation was given intravenously 28 d later, when 100 µl of soluble antigen from 2.5 × 10 5 germlings ml -1 prepared in PBS was injected into the caudal vein of the mice. Three days later, the B-cells were harvested from the spleen of the mice and fused with SP2 myeloma cells to make hybridomas.Hybridomas producing antibodies against Aphanomyces invadans were identified by dot-blot and ELISA (Adams et al. 1995), and positive wells were expanded and recloned 3 times until monoclonal cell lines were obtained. The isotypes of the MAbs were determined by ELISA, using isotype-specific secondary antibodies (Sigma Chemical).Characterisation of MAbs by Western blot: To determine the molecular weights of the antigens recognised by the MAbs, 2 samples of soluble PA8 germling extract, and 1 of extracellular products (ECP) from culture, were prepared. All of the protein was digested from 1 sample of soluble extract by digesting it with 1 mg ml -1 proteinase K (Sigma) for 60 min at 60°C.The ECP was prepared by filtering a broth culture ...

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Section: Staining Of Fixed Germlings By Immunofluorescence Antibody Tsupporting

confidence: 71%

Immunofluorescence of the epizootic ulcerative syndrome pathogen, Aphanomyces invadans, using a monoclonal antibody

Miles¹,

Thompson²,

Lilley³

et al. 2003

Dis. Aquat. Org.

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“…The granulomas described are similar to those reported in Atlantic menhaden with ulcerative mycosis (Noga & Dykstra 1986, Noga et al 1988. Although granulomas did not have epithelioid-like cells, other similarities such as solid nodules in smaller granulomas and 'cystic' granulomas containing remnants of hyphae were apparent.…”

supporting

confidence: 67%

“…However, infections have been reported in menhaden in salinities as high as 13%0 (Noga & Dykstra 1986). Although the topsmelt was captured and held in water at 33%0, the fungus was probably not acquired at that high salinity.…”

mentioning

confidence: 99%

Ovarian mycosis in the topsmelt Atherinops affinis

Winstead¹,

Middaugh²,

Courtney³

1991

Dis. Aquat. Org.

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“…Investigators from both regions considered lesion etiology to be complex, with other environmental factors including high levels of precipitation, agricultural runoff, or nutrient loading playing probable roles in disease expression (6). Massive fish kills were attributed to the disease in North Carolina estuaries (3), and the disease has recurred frequently in subsequent years.…”

mentioning

confidence: 99%

Skin ulcers in estuarine fishes: a comparative pathological evaluation of wild and laboratory-exposed fish.

Vogelbein

Shields

Haas

et al. 2001

Environ Health Perspect

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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 compared the resulting pathology to the so-called Pfiesteria-specific lesions occurring in wild menhaden. The tilapia challenged by high concentrations (2,000-12,000 cells/mL) of P. shumwayaeexhibited loss of mucus coat and scales plus mild petecchial hemorrhage, but no deeply penetrating chronic ulcers like those in wild menhaden. Histologically, fish exhibited epidermal erosion with bacterial colonization but minimal associated inflammation. In moribund fish, loss of epidermis was widespread over large portions of the body. Similar erosion occurred in the mucosa lining the oral and branchial cavities. Gills exhibited epithelial lifting, loss of secondary lamellar structure, and infiltration by lymphoid cells. Epithelial lining of the lateral line canal (LLC) and olfactory organs exhibited severe necrosis. Visceral organs, kidney, and neural tissues (brain, spinal cord, ganglia, peripheral nerves) were histologically normal. An unexpected finding was the numerous P. shumwayae cells adhering to damaged skin, skin folds, scale pockets, LLC, and olfactory tissues. In contrast, histologic evaluation of skin ulcers in over 200 wild menhaden from Virginia and Maryland portions of the Chesapeake Bay and the Pamlico Estuary, North Carolina, revealed that all ulcers harbored a deeply invasive, highly pathogenic fungus now known to be Aphanomyces invadans. In menhaden the infection always elicited severe myonecrosis and intense granulomatous myositis. The consistent occurrence of this fungus and the nature and severity of the resulting inflammatory response indicate that these ulcers are chronic (age >1 week) and of an infectious etiology, not the direct result of an acute toxicosis initiated by Pfiesteria toxin(s) as recently hypothesized. The disease therefore is best called ulcerative mycosis (UM). This study indicates that the pathology of Pfiesteria laboratory exposure is fundamentally different from that of UM in menhaden; however, we cannot rule out Pfiesteria as one of many possible early initiators predisposing wild fishes to fungal infection in some circumstances.

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Oomycete fungi associated with ulcerative mycosis in menhaden, Brevoortia tyrannus (Latrobe)

Cited by 77 publications

References 5 publications

Immunofluorescence of the epizootic ulcerative syndrome pathogen, Aphanomyces invadans, using a monoclonal antibody

Immunofluorescence of the epizootic ulcerative syndrome pathogen, Aphanomyces invadans, using a monoclonal antibody

Ovarian mycosis in the topsmelt Atherinops affinis

Skin ulcers in estuarine fishes: a comparative pathological evaluation of wild and laboratory-exposed fish.

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