bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotyping of Vibrio anguillarum isolated from diseased freshwater fish in Japan
Authors: KITAO T. , AOKI T. , FUKUDOME M. , KAWANO K. , WADA YO. , MIZUNO Y.
Published: April 2006

Abstract. During the period from 1965 to 1980, 263 Vibrio anguillarum strains from ayu, Plecoglossiis altivelis (Temminck & Schlegel), two from rainbow trout. Salmo gairdneri Richardson, and two from eel, Anguilla japonica (Temminck & Schlegel), were collected from fish suffering from vibriosis in various parts of Japan. On the basis of cross‐agglutination and cross‐absorption tests with thermostable (O) antigens, six distinct serotypes (A, B, C, D, E and F) were established among 12 selected strains of V. anguillarum. 241 strains isolated from ayu and two strains from rainbow trout belonged to serotype A, six strains from ayu and one strain from eel to serotype B, 12 strains from ayu to serotype C, three strains from ayu to serotype D, one strain from ayu to serotype E, and one strain from eel to serotype F. V. anguillarum strains belonging to serotypes D, E and F have not been detected from ayu, rainbow trout and eel since 1973; these serotypes appear to be minor types. V. anguillarum strain NCMB 6 and 1669 belong to our serotype A and V. anguillarum 813 to our serotype C.
Glomerular disease in cultured rainbow trout, Salmo gairdneri Richardson, suffering from presumptive chronic viral haemorrhagic septicaemia
Authors: ELGER M. , HENTSCHEL H.
Published: April 2006

Abstract. Severe glomerular changes in the kidney of rainbow trout suffering from presumptive chronic viral haemorrhagic septicaemia are described. The pathological changes, as revealed by light‐ and electron microscopy, resembled those of membranous glomerulonephritis in mammals. Large electron‐dense subendothelial‐mesangial deposits were present in most glomeruli. A lattice‐like arrangement of macromolecules was observed. Monocytes and macrophages were observed in the capillary convolute. The possibility of post‐infectious disease nephropathy with aggregation of immunocomplexes in the capillary wall in fishes is discussed.
Haemic neoplasms of bay mussels, Mytilus edulis L., from Oregon: occurrence, prevalence, seasonality and histopathological progression
Authors: MIX M. C.
Published: April 2006

Abstract. The occurrence, prevalence, seasonality and histopathological progression of a cellular disorder, thought to be a haemic neoplasm, were studied in subpopulations of Mytilus edulis inhabiting different sites in Yaquina Bay, Oregon, from 1976–1981. There were significant differences in the occurrence of the disorder that were related to geographical location. In the subpopulation with the highest levels of the disease, the prevalence rates ranged from 0 to 20% with a 5‐year mean of 9.8 %. There was a statistically significant relationship between prevalence and season. During the 5‐year study period, there was a consistent pattern characterized by highest prevalences during January to March followed by a period of decline to lower levels during the summer and early autumn, after which there was an increase. Data analyses revealed that there was no seasonal histopathological progression of the disorder. Numbers of stage 1 (early), 2, 3 and 4 (advanced) cases were not related to season but occurred in a random manner throughout the entire year.
Serological and histopathological responses of rainbow trout, Salmo gairdneri Richardson, to experimental infection with the 13P2 reovirus
Authors: MEYERS T. R.
Published: April 2006

Abstract. Both fingerling and adult rainbow trout were given intraperitoneal inoculations of the 131P2 reovirus which did not result in mortalities but produced a subclinical disease in 56% of the adults and in 65% of the juvenile fish. Sera from virus infected adult trout contained virus neutralizing and precipitating antibodies and demonstrated immunofluorescence of antigen(s) specific for the 13P2 virus. Virus infection was characterized by increased virus titres and a multifocal reticulo‐endothelial granulomatous hepatitis, occasionally accompanied by a fibrosing pancreatitis. Electron microscopy of infected liver tissues demonstrated arrays of 13P2 virus particles in a reticuloendothelial cell phagosome and in a hepatocyte lipid inclusion body from one of three juvenile fish examined. These results show that 13P2 virus inoculation of rainbow trout causes a non‐virulent virus infection accompanied by specific humoral antibodies. These antibodies are sufficient in titre for use in future serologic studies of the virus. Further discussion regarding the pathogenesis of this virus in bluegills versus rainbow trout is presented.
A new species of Pleistophora from big‐eyes, Priacanthm tayenus Richardson, and P. macracanthus Cuvier and Valenciennes, from the South China Sea
Authors: DING‐KE HUA , HAN‐JI DONG
Published: April 2006

Abstract. Pleistophora priacanthusis sp. nov. is described from big‐eyes, Priacanthus tayenus and P. macracanthus, from the South China Sea. The clinical signs, prevalence, intensity and site of infection of the infected fish, the general effect of the parasite on the host, seasonal distribution and sex differences are reported. The morphology of cysts, spores, sporonts and the characteristic features of the new species using the light microscope are described.
Comparison of efficacy of several delivery methods using Yersinia ruckeri bacterin on rainbow trout, Salmo gairdneri Richardson
Authors: JOHNSON K. A. , AMEND D. F.
Published: April 2006

Abstract. The comparative efficacy of several methods of vaccinating rainbow trout, Salmo gairdneri Richardson, with Yersinia ruckeri bacterins was evaluated. In general, the protective immunity was best by intraperitoneal injection followed by direct immersion, shower and spray, respectively. The bacterin was effective by all methods when diluted 1:20 or less, but there was a trend towards less efficacy with higher dilutions and shorter exposure time.
Prokaryotic infection associated with a mass mortality of the sea scallop, Placopecten magellanicus
Authors: GULKA G. , CHANG PEI WEN , MARTI KAREN A.
Published: April 2006

Abstract. A mass mortality of the deep sea scallop, Placopecten magellanicus, which occurred in the autumn and winter of 1979–80, in Narragansett Bay, Rhode Island was studied. Grossly the animals possessed greyish, flaccid adductor muscles and histologically they showed myodegeneration. Eighty‐eight per cent of the 34 animals examined were infected with intracellular prokaryotes on the gills, plicate membranes and other epithelial surfaces of the body. The morphology of this prokaryotic organism is suggestive of rickettsia. Heavy infection was positively correlated with extensive myodegeneration.
Ceroid deposition, retinal degeneration and renal calcium oxalate crystals in cultured clownfish, Amphiprion ocellaris*
Authors: BLAZER V. S. , WOLKE R. E.
Published: April 2006

Abstract. A clinical syndrome characterized by blindness, loss of pigmentation, erratic swimming behaviour and increased mortality is described in cultured clownfish, Amphipnon ocellaris. Histopathological examination of affected fish revealed retinal degeneration, extensive ceroid deposits in visceral and muscle macrophage accumulations, and renal tubular calcium oxalate crystals. The syndrome is discussed in relation to deficiencies of the fat soluble vitamins A and E and lipid peroxidation. Changes in diet correcting these imbalances resulted in a disappearance of the syndrome.
Histopathologic survey of ovaries of plaice, Pleuronectes platessa L., from Aber Wrac'h and Aber Benoit, Brittany, France: long‐term effects of the Amoco Cadiz crude oil spill
Authors: STOTT G. G. , HAENSLY W. E. , NEFF J. M. , SHARP J. R.
Published: April 2006

Abstract. Ovarian samples were collected from plaice, Pleuronectes platessa, captured in the highly oiled Aber Wrac'h and Aber Benoit estuaries at four intervals during 1979–1980, following the Amoco Cadiz crude oil spill. Reference plaice were obtained along the western and southern coasts of Brittany. Tissue samples were fixed, processed and stained by routine histologic procedures. Ovaries were examined for histopathologic changes and for four different types of follicles. The concentrations and percentages of four types of ovarian follicles (primordial, primary, growing and mature) were determined for plaice ovaries within each sampling site at each sampling interval. Reference site ovaries, which were considered representative of the ovarian cyclic events for plaice along the Brittany coast, had primordial and primary follicles in high concentration in the summer season and in low concentration in the winter season. Concentrations of mature ovarian follicles in reference site plaice ovaries were low in the summer and high in the winter seasons. Growing follicles were observed infrequently in the reference site plaice ovaries. The seasonal pattern exhibited by follicles in ovaries from Aber Benoit plaice was similar to that observed in the reference site ovaries, but both the concentrations and percentages of follicle types were lower. The seasonal pattern of follicle types in Aber Wrac'h plaice ovaries was the reverse of that seen in the reference site plaice ovaries. In the Aber Wrac'h samples, concentrations of primordial and primary follicles were high in the winter months and low in the summer season, and no mature follicles were observed at any season. Growing follicles were seen more frequently in Aber Wrac'h and Aber Benoit plaice ovaries than in reference site plaice ovaries at all sampling intervals. Other than atretic follicles with an associated leucocytosis, no histopathologic conditions were observed in any ovary.
Pathology of vitamin B‐6 deficiency in Channa (=Ophiocephalus) punctatus Bloch
Authors: AGRAWAL N. K. , MAHAJAN C. L.
Published: April 2006

Abstract. Pyridoxine deficiency was experimentally produced in a population of Channa punctatus Bloch by feeding a pyridoxine deficient vitamin test diet for 240 days. The deficiency effects were further accentuated in another group of fish by adding 4‐deoxypyridoxine as an antagonist to the deficient diet. The behaviour, general morphology and growth of these fish were compared with control fish maintained on a complete vitamin test diet. The behavioural study revealed a series of nervous disorders such as ataxia, hyperirritability and muscular spasm followed by convulsions, fits, anorexia and paralysis in the posterior region during advanced stages of the deficiency. Gross morphological changes recorded were retarded growth and loss of weight resulting in a pinhead condition; integumentary damage such as scale loss, leakage of oedematous fluid and abnormal pigmentation, opacity of the lens resulting in complete blindness and enlargement and nodule formation in the spleen and kidney. Recovery treatment for 30 days comprising restoration of dietary supply of pyridoxine supplemented by intramuscular injections brought about considerable recovery in the fish with dietary pyridoxine deficiency but the antagonist‐treated deficient group showed little recovery, although further deterioration was halted.
The adhesion of Vibrio anguillarum to host tissues and its role in pathogenesis
Authors: HORNE M. T. , BAXENDALE A.
Published: April 2006

Abstract. Vibrio anguillarum was shown to adhere to excised sections of rainbow trout gut in numbers which were a function of the concentration of bacterial cells and the time for which the tissue was exposed. Using a standardized method for assaying adhered bacteria the course of infection with vibriosis in rainbow trout was studied. It is suggested that the gut may be an important site of bacterial multiplication in slowly developing infections of mature fish. Bacteria adhere to gut sections of fish protected by vaccination substantially less than to sections from non‐vaccinated fish.
A systemic fungal disease in Atlantic salmon parr, Salmo salar L., caused by a species of Phialophora
Authors: ELLIS A. E. , WADDELL I. F. , MINTER D. W.
Published: April 2006

Abstract. A fungal infection of Atlantic salmon parr (0 +) occurring at low water temperatures, principally in January, is reported from fish farm hatcheries in western Scotland. Clinical signs and histopathology of the disease are described, illustrated, discussed and compared with those of certain other fungal diseases of salmonids. The fungus, provisionally placed in the hyphomycete genus Phialophora is described and illustrated from pure culture, with a discussion of its taxonomic position.
In vitro antibacterial activity of the combination of sulphadiazine and trimethoprim on bacterial fish pathogens
Authors: KIMURA T. , YOSHIMIZU M. , WADA M.
Published: April 2006

Abstract. The in vitro bacteriostatic activity of a combination of sulphadiazine (SDZ) and trimethoprim (TMP) against representative bacterial fish pathogens was studied. In general, the minimum inhibitory concentrations (MIC) of TMP were much smaller than comparable values for SDZ. When SDZ and TMP were combined, the bacteriostatic effect was enhanced in a synergistic manner for all bacteria tested except Pseudomonas fluorescens. The synergism was most remarkable in the case of bacterial strains that were sensitive to the action of SDZ alone. This degree of synergism was observed when the ratios of SDZ and TMP in combination were in the range of 1:1 io 5:1. The MIC of SDZ plus TMP combined was less than 3.13 μg/ml for SDZ resistant strains and as low as 0.2 to 0.78 μ/ml for SDZ sensitive strains. The possible usefulness of a combination of these two compounds for therapy or control of bacterial fish disease is discussed.
An ultrastructural study of the cellular response of the plaice, Pleuronectes platessa L., to Rhipidocotyle johnstonei nom. nov. (pro‐Gasterostomum sp. Johnstone, 1905) Matthews, 1968 (Digenea: Bucephalidae)
Authors: PULSFORD ANN , MATTHEWS R. A.
Published: April 2006

Abstract. An ultrastructural study of the cellular response of plaice to Rhipidocotyle johnstonei nom. nov. Matthews, 1968, revealed a chronic inflammatory lesion containing cells mainly of the mononuclear phagocyte series. The ‘granuloma’ included monocytes, macrophages, epithelioid cells and multinucleated cells with peripheral fibrocytes. The presence of small numbers of lymphocytes and plasma cells in the mature granuloma suggests a cell‐mediated response. The parasite becomes adult within two months and survives for approximately 10 months, the capsules becoming increasingly fibrotic. Heavy infections in young fish cause fin erosion, haemorrhage and probably impair muscle function, increasing the risk of predation.
A lymphosarcoma of thymic origin in the rainbow trout, Salmo gairdneri Richardson
Authors: WARR G. W. , GRIFFIN B. R. , ANDERSON D. P. , MCALLISTER P. E. , LIDGERDING B. , SMITH C. E.
Published: April 2006

Abstract. A rainbow trout with a malignant lymphoma of probable thymic origin showed direct spread of the tumour to the gills, metastases to the liver and head kidney, and the presence of abnormal circulating lymphocytes. The cells of the tumour possessed plasma membrane immunoglobulin detectable by immuno–fluorescence. Examination of the tumour cells by transmission electron microscopy revealed no evidence of virus associated with the cells. Infectious viruses could not be detected in the tumour tissue, and the tumour was not transmissible by injection of live tumour cells into young rainbow trout. Attempts to establish the tumour in long–term culture were unsuccessful.
Potential for immersion vaccination against Aeromonas salmonicida
Authors: JOHNSON K. A. , AMEND D. F.
Published: April 2006

Abstract. The efficacy of the immersion method of vaccination was evaluated using Aeromonas salmonicida bacterin. In general a 2 min immersion vaccination was not as effective as vaccination by intraperitoneal injection; however, the level of immunity was improved by giving multiple vaccinations several days apart. A primary immersion vaccination with bacterin diluted 1:4 followed by a secondary vaccination diluted 1:2 gave good results. The most concentrated secondary booster was more effective than boosting with more dilute bacterin.
Serological relationships among five strains of infectious pancreatic necrosis virus
Authors: ISHIGURO S. , IZAWA H. , KODAMA H. , ONUMA M. , MIKAMI T.
Published: April 2006

Abstract. The serological relationships of five strains of infectious pancreatic necrosis virus (IPNV) were examined by cross‐neutralization, cross‐fluorescent antibody (FA) and cross‐immunodiffusion (ID) tests. Few serological relationships among these strains were observed by the cross‐neutralization test, which is consistent with previous studies. Some cross reactions were observed by the FA test when antisera were reacted with cells infected with heterologous strains of IPNV. However, close antigenic relationships were demonstrated among these strains of IPNV by using the ID test when antisera to each strain of IPNV were titrated with their respective or heterologous antigens. The results of the present study showed that substantial antigenic relationships exist among the strains of IPNV examined. It is suggested that strain specific antigens which can be detected by virus neutralization and FA tests might exist on the surface of the virion. The FA test proved to be a useful method for detecting viral antigens of several strains of IPNV in tissue culture cells since monovalent antiserum reacted with homologous and heterologous IPNV antigens.
Histopathology and enlargement of the pituitary of a teleost exposed to the herbicide trifluralin
Authors: COUCH J. A.
Published: April 2006

Abstract. Pituitaries of sheepshead minnows, Cyprinodon uariegatus, exposed for 19 months to 1‐5 μg/l trifluralin in the laboratory exhibited enlargement, pseudocysts, congestion of blood vessels and oedema. Most of the fish with an enlarged pituitary also had induced diffuse and/or focal vertebral hyperostosis and other dysplastic vertebral changes. Several speculative mechanistic paths are suggested for the mode of effect of trifluralin on the vertebral and pituitary tissues. Abnormal enlargement or variation in sizes of pituitaries from fish of the same age, along with histopathological findings may be related to the environmental quality of the fish's habitat, and provide indications of stress within individuals resulting from toxicant exposure.
Ankylosing spondylosis in the giant perch, Lates calcarifer (Bloch)
Authors: LESTER R. J. G. , KELLY W. R.
Published: April 2006

Abstract. A disease of the vertebral column is described in three adult wild‐caught Lates calcarifer (Bloch) from the Northern Territory, Australia. It is characterized by the deposition of bone in the intervertebral space thus fusing the vertebrae, and the development of a thick gelatinous mass of loose connective tissue around the affected part of the vertebral column. Though a Clostridium sp. was isolated from one fish, it was not thought to be the primary cause.
Proliferative kidney disease: first reported outbreak in North America
Authors: SMITH C. E. , MORRISON J. K. , RAMSEY H. W. , FERGUSON H. W.
Published: April 2006

Abstract. Proliferative kidney disease (PKD) was diagnosed in rainbow trout, Salmo gairdneri Richardson, at the Hagerman, Idaho, State Fish Hatchery. Wild fish from Riley Creek, one of the hatchery water supplies, were infected with PKD organisms. Clinical signs, gross pathology and histopathology of affected fish were typical of those reported for PKD in salmonids from European hatcheries. In addition to lesions normally seen, we observed a severe vasculitis and occlusion of renal and hepatic vessels. Ultrastructure of the PKD organism and possible inclusion body production sites are described. The disease outbreak was complicated by the presence of other infectious diseases. This is the first recorded outbreak of PKD in North America.
A calcified fibroma in the common carp, Cyprinus carpio L.
Authors: MANIER J. F. , RAIBAUT A. , LOPEZ A. , RIOUX J.‐A.
Published: April 2006

Abstract. A large tegumental tumour was observed in a common carp from the pool of the Jardin des Plantes, Montpellier. The tumour was a fibroma characterized by centripetal fibrogenesis and intense calcification of the central region.
Control of the bass tapeworm, Proteocephalus ambloplitis (Leidy), with mebendazole
Authors: BOONYARATPALIN S. , ROGERS W. A.
Published: April 2006

Abstract. Mebendazole (methyl‐5‐benzoyl benziraidazole‐2‐carhamate) was shown to have anthelmintic activity against larvae of Proteocephalus ambloplitis (Leidy) in implantations were found to be highly effective. A single intraperitoneal injection of 200 mg/kg or a capsule implantation of 200 mg/kg of mebendazole each reduced the infection by 95 % after 6 weeks. Oral treatment for 14 consecutive days at 100 mg/kg/ day reduced I he infection by 90%. Intraperitoneal injection of 200 mg/kg of mebendazole ever, did not interfere with spawning and reproduction of largemouth bass; however fish injected with 300 mg/kg produced no fry. Haematocrit, total haemoglobin, total serum protein and histological changes were not evidenl in treated fish.
A histological assessment of damage in rainbow trout, Salmo gairdneri Richardson, fed rations containing erythromycin
Authors: HICKS B.D. , GERACI J.R.
Published: April 2006

Abstract. Rainbow trout fed prepared rations containing therapeutic levels of erythromycin (110 mg/kg daily) developed lesions in epithelial cells of the first proximal segment of the nephron. Pathological changes which developed within 24 h were characteristic of congestive overloading of lysosomes. Treated fish became anorexic within 2–3 weeks. Affected epithelial cells offish after 14 days of anorexia contained residual bodies in an otherwise normal appearing cytoplasm. Cell injury was reversible. Since the onset of anorexia corresponded with the completion of the recommended treatment period and damaged cells repair rapidly, erythromycin should nevertheless be retained as the treatment of choice for bacterial kidney disease.
Unilateral exophthalmos in Sebastes spp.: histopathologic lesions
Authors: ENGELMAN R. W. , COLLIER L. L. , MARLIAVE J. B.
Published: April 2006

Abstract. A spontaneous unilateral exophthalmos occurring in five species of otherwise healthy rockfish, Sebastes spp., was investigated. All eyes from nine unilaterally exophthalmic and seven non‐exophthalmic rockfish were examined grossly and histologically. In all affected fish the exophthalmos was due to enlargement of the globes resulting from the formation of choroidal cysts filled with a clear, watery fluid and surrounded by dense, aberrant connective tissue. Cyst formation led to gross distortion and disorganization of the choroid. Distorted remnants of the choroidal rete mirabile contained markedly fewer erythrocytes, a homogeneous proteinaceous material and a mild inflammatory cell infiltrate. Thickened scleral cartilage with disoriented chondrocytes was also present in exophthalmic eyes. Some of the affected eyes showed pigmentary abnormalities with clumps of heavily pigmented cells present in the retina and choroid. Retinal degeneration and detachment was also evident in some of the affected eyes.
The non‐specific activation of rainbow trout, Salmo gairdneri Richardson, complement by Aeromonas salmonicida extracellular products and the correlation of complement activity with the inactivation of lethal toxicity products
Authors: SAKAI D. K.
Published: April 2006

Abstract The possible mechanism of inactivation of the toxicity of Aeromonas salmonicida extracellular products (ECP) by normal rainbow trout serum was investigated using juvenile rainbow trout. ECP was prepared from culture supernatant by an acetone precipitation method. The ECP was incubated with normal rainbow trout serum at 20°C for 2 h, and the interrelationship between ECP proteolytic activity and immune complex‐initiating, haemolytic complement activity (CH50) of normal serum against antibody‐sensitized goldfish red blood cells was evaluated. When normal serum was incubated with increasing concentrations of ECP, the CH50 activity of serum decreased. The CH50 activity was completely abolished in serum treated with undiluted ECP. ECP treated with serum was administered to trout intraperitoneally to determine mortality. All the fish receiving untreated ECP (0.05 ml = 0.5 mg protein) alone died within 24 h. When ECP was treated with serum at 1:1 to 4:1 (serum: ECP) in volume a similar high mortality was produced. These inocula possessed high protease activity and no or low CH50 activity. However, mortality decreased and finally no mortality was recorded as ECP was treated with large volumes of serum (9:1 to 19:1). These inocula had lower protease activity and considerably higher CH50 activity. Fish receiving ECP treated with heat‐inactivated serum at 19:1 showed 100% mortality. A serum: ECP inoculum derived from fish which had been administered lipopolysaccharide from Salmonella enteritidis and which possessed a low CH50 activity also gave a high mortality when used at 19:1. These results suggest that rainbow trout complement is implicated in the inactivation of toxicity of A. salmonicida ECP.
The reticulo‐endothelial system of the adult river lamprey,Lampetra fluviatilis(L.): the fate of intravascularly injected colloidal carbon
Authors: PAGE M. , ROWLEY A. F.
Published: April 2006

AbstractThe fate of intravascularly‐injected colloidal carbon was followed using routine light and electron microscopical techniques. The colloid was observed in the gills, heart, liver, kidney, supraneural organ, blood and areas near the site of injection. There was no apparent build up, removal or translocation of the colloid over the time periods examined (1 h‐12 days) except in the blood, where the carbon was cleared from the plasma after about 3 h. Carbon‐containing granulocytes were, however, present in the blood up to 12 days post‐injection. Most of the carbon was localized in the cavernous bodies of the gills, the intertubular tissues of the kidney and the supraneural organ where it was found within phagocytic cells containing melanin pigments. These cells are compared to the melano‐macrophages of higher fish and their possible role in antigen trapping and antibody formation is discussed.
Pathogenicity and infectivity of a rickettsia‐like organism in the sea scallop, Placopecten magellanicus
Authors: GULKA G. , CHANG PEI WEN
Published: April 2006

Abstract. A rickettsia‐like organism from the gills and plicate membrane of the sea scallop, Placopecten magellanicus, was prevalent in near‐shore Rhode Island scallop populations such as Block Island Sound and Narragansett Bay, but relatively scarce in Georges Bank samples. Fifty‐three per cent of scallops transplanted in cages to Narragansett Bay became infected with the rickettsiae in 2.5‐3.5 months. Scallops that were transferred to aquaria with Narragansett Bay water were 100% infected with rickettsiae in 5 months or less. There is some evidence that heavy infection of P. magellanicus inhibits swimming response and that rickettsial infection may contribute indirectly to mortalities by reducing scallop mobility and avoidance of predators. The organism was successfully cultured in gill organ culture and by direct injection of infected tissue homogenate, but could not be grown on artificial media or in yolk sac of embryonated hens’ eggs. Other bivalve species could not be infected with the rickettsia of P. magellanicus through the water column or by direct injection.
Detection of transferable R plasmids in strains of the fish–pathogenic bacterium, Pasteurella piscicida
Authors: AOKI T. , KITAO T.
Published: April 2006

Abstract. Sixty strains of Pasteurella piscicida were collected from cultured yellow–tail, Seriola quinqueradiata Temminck & Schlegel, in various districts of Japan. These strains were tested for their sensitivity to 14 different chemotherapeutic agents and the detected drug resistant strains were investigated to determine whether or not they possessed R plasmids. All strains were most susceptible to ampicillin of the tested drugs. All except five strains were found to be susceptible to chloramphenicol (CM) and doxycycline (DOTC). However, the strains were only moderately susceptible to cephazolin, cephalexin, nalidixic acid, trimethoprim and ormethoprim, and their MIC values were under 3–lμg/ml. Twenty–one strains showed resistance to furazolidone (NF). Five out of the 60 strains were resistant to CM, tetracycline (TC), kanamycin (KM), NF and sulphamonomethoxine (SA). Transferable R plasmids were detected in these drug–resistant strains. These R plasmids had markers for resistance to CM, TC, KM and SA.
Epizootiology of Renibacterium salmoninarum, the causal agent of bacterial kidney disease in salmonid fish
Authors: AUSTIN B. , RAYMENT J. N.
Published: April 2006

Abstract. By use of a selective medium, Renibacterium salmoninarum was recovered from rainbow trout, Salmo gairdneri Richardson. With asymptomatic animals, small numbers of Renibacterium colonies were recovered only from the anterior part of the kidney; whereas in clinically diseased fish, dense pure culture growth was obtained from kidney, spleen, heart, blood, ascitic fluid and faeces. There was no evidence for the presence of R. salmoninarum in the water or sediment of 56 freshwater fish farms in England and Wales. Nevertheless, laboratory–based experiments showed that the pathogen was excreted in the faeces of clinically diseased fish. Moreover, there was survival of the bacterial cells for up to 21 days in sediment/faecal material.
Moderation of the experimental carrageenin granuloma in the plaice, Pleuronectes platessa L., by reduction in temperature
Authors: TIMUR M. , TIMOR G. , ROBERTS R. J.
Published: April 2006

Abstract. A standard carrageenin granuloma was induced in adult plaice, Pleuronectes platessa L., maintained at 5°C and its pathogenesis followed histologically for 3 months. All of the stages of granulation were considerably delayed compared to similar lesions reported at 10°C. The lesion was only partly resolved at the end of the study, and many of the cellular changes were less exuberant and less well‐defined than those reported for 10°C.
A comparison of detection methods for infectious haematopoietic necrosis virus
Authors: HSU Y. L. , LEONG J. C.
Published: April 2006

Abstract. A comparative study of immunological methods for detecting infectious haematopoietic necrosis virus (IHNV) was made. The anti–IHNV antibody titre was measured by solid phase direct binding assays with‘125iodinated Protein A from Staphylococcus aureus and with immunoperoxidase staining. The binding antibody titre was much higher than that obtained in the virus neutralization assay. The high binding antibody titre of rabbit anti–IHNV sera made the development of two immunological tests for IHNV possible. Virus–specific proteins were detected on nitrocellulose membranes after transfer from denaturing polyacrylamide gels. The immunological methods were highly specific, sensitive lo less than 10 ng of virus protein, and were useful in characterizing the different strains of IHNV.
Pathological conditions in the liver of ruffe, Gymnocephalus cernua (L.), from the Elbe estuary
Authors: KRANZ HEIDEMARIE , PETERS N.
Published: April 2006

Abstract. During a 3‐ycar study of the ruffe population in the highly polluted Elbe estuary, 551 fish were examined for grossly visible liver lesions. Three main types of abnormalities were distinguished, and the histological characteristics of representative livers are described. The rate of occurrence of each abnormality was recorded and correlated with the length of the affected fish. The livers in 11%; of the ruffe were uniformly discoloured due to excessive deposition of fat in the hepatocytes. In 39% of the livers, localized pale flecks, patches, or marbled patterns were observed. A subsample examined histochemically revealed that these were also due to fat deposition, except in a few cases resulting from excessive glycogen accumulation. Distinct from these two syndromes were pale nodules in the hepatic tissue seen in 8% of the ruffe. Microscopy showed the nodules to be neoplastic. A relationship between fish length and prevalence was found only in the case of these nodules. Possible causes of the various liver abnormalities found are discussed.
Evidence for the presence of a viral non‐lymphocystis type disease in winter flounder, Pseudopleuronectes americanus (Walbaum), from the north‐west Atlantic
Authors: EMERSON C. J. , PAYNE J. F. , BAL A. K.
Published: April 2006

Abstract. A non‐lymphocystis type disease associated with virus particles has been documented in winter flounder, Pseudopleuronectes americanus (Walbaum), taken from a small estuary in Conception Bay, Newfoundland. The papillomatosis‐type lesions found on the dorsal surface of the fish contained numerous electron‐dense particles, approximately 30 nm in diameter. A number of lines of evidence, including cytochemical studies, indicated that the particles were not glycogen but virions. Sensitivity to deoxyribonuclease enzyme treatment and the presence of crystalline viral‘factories’ in the nuclei of infected cells further suggested that the particles were small DNA virions. Characteristics including nucleic acid composition, particle size, site of multiplication and the lack of an envelope indicate that this fish virus is similar to the Papovaviridae and Parvoviridae families of mammalian viruses. Lymphocystis is common in flatfish populations along the Newfoundland and Labrador coasts of the N.W. Atlantic, but this is the first record of flatfish infection with a small DNA virus.
Evidence for the presence of a viral non‐lymphocystis type disease in winter flounder, Pseudopleuronectes americanus (Walbaum), from the north‐west Atlantic
Authors: EMERSON C. J. , PAYNE J. F. , BAL A. K.
Published: April 2006

Abstract. A non‐lymphocystis type disease associated with virus particles has been documented in winter flounder, Pseudopleuronectes americanus (Walbaum), taken from a small estuary in Conception Bay, Newfoundland. The papillomatosis‐type lesions found on the dorsal surface of the fish contained numerous electron‐dense particles, approximately 30 nm in diameter. A number of lines of evidence, including cytochemical studies, indicated that the particles were not glycogen but virions. Sensitivity to deoxyribonuclease enzyme treatment and the presence of crystalline viral‘factories’in the nuclei of infected cells further suggested that the particles were small DNA virions. Characteristics including nucleic acid composition, particle size, site of multiplication and the lack of an envelope indicate that this fish virus is similar to the Papovaviridae and Parvoviridae families of mammalian viruses. Lymphocystis is common in flatfish populations along the Newfoundland and Labrador coasts of the N.W. Atlantic, but this is the first record of flatfish infection with a small DNA virus.
Strawberry disease in rainbow trout, Salmo gairdneri Richardson
Authors: OLSON D. P. , BELEAU M. H. , BUSCH R. A. , ROBERTS S. , KRIEGER R. I.
Published: April 2006

Abstract. Strawberry disease is a subchronic, non–debilitating, and non–fatal inflammatory skin disease of rainbow trout that has been recognized for the past 25 years. Morbidity ranges up to 80% and the disease affects fishes from 15cm in length to brood stock size. Epizootiological data indicate that strawberry disease usually appears, first in the autumn and reaches peak incidence during the following winter and spring. Data also indicate that the disease is found only in certain trout farms in the western and Pacific north–western regions of the United States. Although the cause of strawberry disease is unknown, the normal clinical course of 8 weeks can be reduced by oral treatment with oxytetracycline. Clinical signs include appearance of bright red, raised, circumscribed, ulcerated and indurated lesions in the skin that usually range up to 3 cm or more in diameter. Microscopically, the disease is characterized as a subchronic, focal, non–suppurative dermatitis with ulceration and extensive infiltration of mononuclear inflammatory cells.
Efficacy of specific antibody against agglutinating Aeromonas salmonicida strains on infectivity and vaccination with inactivated protease
Authors: SAKAI D. K.
Published: April 2006

Efficacy of specific antibody on serum resistance and adhesion was investigated using a pathogenic strain of Aeromonas salmonicida A‐7301 (which was autoagglutinative, haemagglutinative and protease production positive), a protease‐deficient, non‐pathogenic mutant NTG‐1 induced from A‐7301 (autoagglutinative and haemagglutinative), and a non‐pathogenic strain GH‐7501 (non‐agglutinative, non‐haemagglutinative and protease positive). A‐7301 could grow and produce protease extracellularly in the presence of rainbow trout anti‐A‐7301 serum, resulting in a considerable reduction of the antibody titre. NTG‐1 similarly grew, but the titre scarcely decreased. GH‐7501 could not survive in this medium. A‐7301 and NTG‐1 possessed a high capacity to adhere to the surface of fish monolayer cell cultures, whereas GH‐7501 lacked the capacity. The capacity for adhesion was not inhibited by the antibody. Although live NTG‐1 cells were ineffective as a live vaccine, sockeye salmon receiving protease fraction (obtained from extracellular products of A‐7301 by DEAE‐cellulose column chromatography) inactivated with normal serum, suffered only a low mortality when challenged with A‐7301. Thus, although the antibody specific to autoagglutinating cells showed no effects on serum resistance and adhesion, which are involved in the infectivity of this pathogen, the possibility of protease as an effective protective antigen was demonstrated.
Intestinal pathology in northern pike, Esox lucius L., infected with Triaenophorus crassus Forel, 1868 (Cestoda: Pseudophyllidea)
Authors: SHOSTAK A. W. , DICK T. A.
Published: April 2006

Abstract. Pathology surrounding the attachment site of Triaenophorus crassus Forel, 1868 in the intestine of northern pike, Esox lucius L., was described. The scolex caused ulceration of the mucosa and lamina propria. Cellular infiltration and collagen deposition in the tissue surrounding the scolex raised the scotex into the lumen in isolated nodules, or produced a general thickening of the lamina propria. The lesion was well vascularized, with haemorrhaging and sloughing of epithelium at the lumenal surface, but with limited necrosis at the surface or within the lesion. Thickening of the lamina propria and circular muscle layer underlying regions with dense attachment sites produced an external swelling of the intestine and caused a decrease in the lumen to about one‐fifth normal diameter. The nematode Raphidascaris acus was present within the degenerating lamina propria which surrounded attachment sites of T. crassus, but the cestode Proteocephalus pinguis was only found attached in areas with intact villi.
The disease status of Australian salmonids: viruses and viral diseases
Authors: LANGDON J. S. , HUMPHREY J. D. , COPLAND J. , CAROLANE R. , GUDKOVS N. , LANCASTER C.
Published: April 2006

Abstract. Eleven freshwater salmonid hatcheries in southern Australia were surveyed for the presence of viruses and viral diseases. Tissues from a total of 6025 fish of five salmonid species were cultured for viruses on RTG‐2, BF‐2 and FHM cell lines. No viruses were detected. The study strongly suggests that Australian salmonid populations are free of the cytopathic salmonid viruses. This virus‐free status is of economic significance for the production and export of ova and other salmonid products, and deserves stringent quarantine protection.
Infection of a cultured freshwater prawn, Macrobrachium rosenbergii de Man (Crustacea: Decapoda), by Mycobacterium spp., Runyon Group II
Authors: BROCK J. A. , NAKAGAWA LAUREN K. , SHIMOJO R. J.
Published: April 2006

Abstract. A mycobacterial infection of a freshwater prawn, Macrobrachium rosenbergii de Man, is described. The causative organism was isolated and identified as Mycobacterium sp., Runyon Group II.
Immunosuppression in rainbow trout, Salmo gairdneri Richardson, caused by the haemoflagellate Cryptobia salmositica Katz, 1951
Authors: JONES S. R. M. , WOO P. T. K. , STEVENSON R. M. W.
Published: April 2006

Abstract. An experimental Cryptobia salmositica infection in rainbow trout, Salmo gairdneri Richardson, produced suppression of the humoral response against sheep red blood cells as measured by direct haemagglutination. Two‐month and 5‐month infections produced equal suppression. The parasite also produced suppression of the humoral response against a bacterial pathogen, Yersinia ruckeri. Anti‐Y. ritckeri titres were significantly lower in most fish infected with C. salmositica than in non‐infected fish. Immunosuppression became evident when C. salmositica first appeared in the blood (first 2 weeks of infection), Immunosuppression was confirmed by challenge with Y. ruckeri. Mortality at challenge occurred in 64·3% to 83·3% of the fish already infected with C. salmositica at the time of initial Y. ruckeri exposure. There was no mortality at challenge if fish were not infected with C. salmositica at initial bacterial exposure, nor in those concurrently infected with both pathogens. Antigenic competition may have caused the immunosuppression.
Use of monoclonal antibodies in the indirect fluorescent antibody technique (IFA) for the diagnosis of Edwardsiella ictaluri*
Authors: AINSWORTH A. J. , CAPLEY G. , WATERSTREET P. , MUNSON D.
Published: April 2006

Abstract. Forty‐five channel catfish, Ictalurus pitnctaius (Rafinesque), fingerlings were inoculated with Edwardsiella ictaluri to determine the usefulness of monoclonal antibodies for indirect fluorescent antibody techniques for confirming clinical diagnosis of enteric septicaemia of catfish. Bacteriological and indirect fluorescent antibody results were compared statistically and found to correlate in 90·3% of the cases. A method for incorporating monoclonals for indirect fluorescent antibody into the speciation of Edwardsiella ictaluri and the use of monoclonal antibodies in diagnosis is described.
Idiopathic muscle necrosis in the freshwater prawn, Macrobrachium rosenbergii de Man, cultured in Thailand
Authors: NASH G. , CHINABUT S. , LIMSUWAN C.
Published: April 2006

Abstract. A mass mortality of up to 60% per tank occurred in 28‐day‐old Macrobrachium rosenbergii postlarvae cultured under intensive conditions in a hatchery in Thailand. Grossly affected prawns displayed a diffuse ‘milky’ white body opacity; histologically and ultrastructurally, segmental myofibre (myofibrillar and sarcoplasmic) necrosis unassociated with any infectious agents was observed, and was diagnosed as idiopathic muscle necrosis. Avoidance of overstocking and increased dissolved oxygen in tank water have proved effective in preventing subsequent recurrences of the condition.
A histological study of the response to challenge with vibriosis in ayu, Plecoglossus altivelis Temminck and Schlegel, vaccinated by immersion and injection with Vibrio anguillarum bacterin
Authors: MIYAZAKI T.
Published: April 2006

Abstract. The histological responses of ayu, Plecoglossus altivelis, given an intramuscular injection of a formalin‐killed bacterin of Vibrio anguillarum are described. Lesions at the site of injection showed muscular necrosis and infiltration of inflammatory cells by the second day after injection, and production of granulation tissue from the fifth to the fourteenth day. Protective responses against vibriosis were studied histopathologically in ayu that were vaccinated by intramuscular injection with formalin‐killed Vibrio bacterin and by immersion in sonicated Vibrio bacterin, and challenged by a subcutaneous injection with viable Vibrio on the fourteenth day after the vaccination.

Efficacy of both methods was confirmed by the survival of vaccinated fish after the challenge. There was slight bacterial multiplication in the fish, and bacterial phagocytosis by infiltrated neutrophils and tissue necrosis in the injected area on the third day after the challenge. In contrast, non‐vaccinated fish died within 24h of challenge, with extensive bacterial multiplication and tissue necrosis in the injected area and visceral organs.
A case history of whirling disease in a drainage system: Battle Creek drainage of the upper Sacramento River basin, California, USA
Authors: HORSCH C. M.
Published: April 2006

Abstract. Whirling disease was diagnosed in steelhead trout, Salmo gairdneri Richardson, during 1985 at Coleman National Fish Hatchery in the Battle Creek drainage of the upper Sacramento River basin, California, USA. Early confirmation of the aetiologic agent, Myxobolus cerebralis Hofer, 1903, was difficult. However, later investigation confirmed the identity of the agent and led to a management decision to destroy the 1985 brood year of steelhead trout at the hatchery. Sentinel fish and collections of feral trout were used to survey Battle Creek watershed to determine the source of infectivity. Feral rainbow trout, Salmo gairdneri Richardson, from South Fork Battle Creek were found to be infected with M. cerebralis and other infected trout were later found at two commercial rainbow trout hatcheries. No reinfection with M. cerebralis has been detected at the Coleman hatchery since ozonation was begun in early 1986.
The plasmid profile of Edwardsiellaictaluri*
Authors: SPEYERER P. D. , BOYLE J. A.
Published: April 2006

Abstract. The plasmid content of 18 isolates of Edwardsiella ictaluri found in channel catfish was analysed by agarose gel electrophoresis. Each isolate contained an identical set of plasmids. This set consisted of two prominent plasmids of 5.2 and 4.4 kilobase pairs, and three smaller and less apparent plasmids. One plasmid (the 5.2 kilobase plasmid) was radiolabelled and used to probe a blot of DNA from all isolates. All plasmids were hybridized but no chromosomal DNA was labelled. These plasmids must share some homologous regions. DNAs from other bacteria, including the related Edwardsiella tarda, were also probed and no hybridization was seen. It is suggested that a plasmid probe may be a sensitive, specific probe for detection of E. ictaluri in channel catfish
Introduction and establishment ofGyrodactylus salarisMalmberg, 1957, on Atlantic salmon,Salmo salarL., fry and parr in the River Vefsna, northern Norway
Authors: JOHNSEN B. O. , JENSEN A. J.
Published: April 2006

Abstract.Gyrodactylus salariswas probably introduced into the River Vefsna, a large salmon river in northern Norway, by stocking of Atlantic salmon smolts from infected hatcheries in 1975 and 1977. An outbreak ofG. salarisamong salmon parr was observed in 1978. During the following 2 years, the parasite spread throughout the entire watercourse. There was a rapid rise in prevalence rate and degree of infection. The density of salmon parr decreased from a high level before theGyrodacrylusoutbreak to close to zero after the outbreak. Salmon parr mortality is probably associated with an increase in the parasite burden. Infected fish appear to survive for slightly more than 1 year and this time period is sufficient for transmission of the parasite to the next year class. The total catch of salmon ascending the river has also greatly decreased in recent years.