Fish Pathology
Online ISSN : 1881-7335
Print ISSN : 0388-788X
ISSN-L : 0388-788X
Volume 20 , Issue 2-3
Showing 1-42 articles out of 42 articles from the selected issue
  • H.-J. SCHLOTFELDT, W. NEUMANN, H. FUHRMANN, K. PFORTMUELLER, H. BOEHM
    1985 Volume 20 Issue 2-3 Pages 85-91
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Increasing resistance of specific-fishpathogenic and facultative-fishpathogenic bacteria against the main drugs licensed in Germany.
    With an average of yearly 600 examined cases-including the whole range of additional virological-, bacteriological-, histological-, water quality and residual. tests-the Fish Health Service (FHS) of Hannover of the Northern Federal State of LOWER SAXONY reached within the last years some representative experience dealing with the control and therapy of fish diseases in aquaculture. The control of the three notifiable viral epidemics of freshwater fish presently included in the pertinentlegislation (Animal Epidemics Act) of the FRG-VHS, IPN and SVC-is the competence of the STATE FISH EPIDEMICS CONTROL SERVICE OF LOWER SAXONY from which the FHS mentioned above is a part. The therapy of bacterial diseases-essentially Aeromonas salmonicida infections (Furunculosis/Salmonids; Erythrodermatits/Cyprinids), vibriosis, from 1981 on increasingly Enteric Redmouth Disease/ERM (with an unexpected peak in late winter-, spring and summer 1984) as well asthe mainly environment dependent-sometimes with septicemic development of the whole range of ubiquitous facultative-fishpathogenic bacteria from the aquatic environment-developed rather unprob lematic and successful in Lower Saxony for many years. From 1981 on a change in this situation with concomitant increasing resistance of specific-fishpathogenic as well as facultative-fishpathogenic bacteria. against the main drugs licensed in the FRG and used in the control of freshwater fish diseases mainly through medicated feed is observed. The bacterological examination with antibiogramme proved indispensable. In the FRG the presently licensed drugs for treatment of bacterial infections in fish are Chloramphenicol, Chlor- and Oxitetracycline, Furazolidone, Trimethoprim/Sulfadimethoxine and Nifurpracine. In the FRG Chloramphenicol was forbidden for use in domestic animals (homoeotherms) for human consumption in April 1984. It is to assume that Chloramphenicol will be withdrawn for use in fish soon. Only in few individual cases and strictly controlled by the veterinary authorities some otherdrugs can be experimentally tested under prescription and strict supervision of a veterinarian specialized in fish diseases and aquaculture. Besides the substances mentioned above antibiogrammes are routinely carried out with Oxolinic acid, “Lincospectin” (Lincomycine + Spectinomycine 1 : 2), Ampicilline, Erythromycine and very recently Flumequine.
    The results of 596 FHS-cases from which in 289 the bacteriological examination proceed necessaryfrom them in 162 cases the antibiogramme was feasible-carried out within the frame of the work of the FHS from January 1983 to May 1984 are discussed-, the increased resistance showed-, the effectivity and/or uselessness of some of the drugs presented. Flumequine, Oxolinic acid, Lincospectine (not yet licensed in the FRG) and last but not least the tetracyclines showed promising. The finding of few Aeromonas salmonicida subsp. salmonicida isolates completely resistant against the drugs licensed in the FRG may involve further serious problems as well as cases of total failure of therapy carried out in strict accordance with the antibiogramme if a chronic viral infection is present in the background-as e.g. observed with ERM concomitant to VHS. The results of a first field trial with Oxolinic acid in a rainbow trout population during summer of 1984 are shown. As a main result of this trials it is recommended to 86 enlarge the presently narrow frame of drugs licensed for fish in the FRG by at least two of the compounds tested: Oxolinic acid and Fluméquine, or Oxolinic acid and Lincospectin; and to delete Ampicilline which was included in a pertinent priority list in 1982.
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  • Nour El-Din AMIN, I.S. ABDALLAH, T. ELALLAWY, S.M. AHMED
    1985 Volume 20 Issue 2-3 Pages 93-97
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A total of 25 T. nilotica (S. niloticus) fish showing clinical altrations were subjected to clinical, P. M., complete parasitologic and bacteriologic examinations. Results of clinical and post-mortem examinations revealed two forms of the disease:
    1. The first was characterized by redness of the skin, presence of haemorrhagic patches of various size distributed all over the body and fins, exophthalmia and anal prolapse with abdominal distention, which was considered as the acute septicaemic form of the disease.
    2. The second was characterized by roughness of the scales and their detachment from some parts of the body and formation of ulcers which were small at first, then became enlarged, have irregular shape, white centrally, surrounded by hyperemic zone and found on the lateral sides of the body. This was classified as chronic ulcerative form of the disease.
    Parasitologic examination of diseased fish revealed the presence of Ichthyophthirius multifilis protozoan which was considered as a stress factor.
    Bacteriologic examination of diseased fish revealed the presence of fourteen isolates of bacteria, morphologically and biochemically related to Aeromonas hydrophila.
    Biological experiments conducted on T. nilotica yearlings revealed that eight isolates of A.. hydrophila were highly virulent, three isolates were moderately virulent and the other three isolates were avirulent to the tested fish.
    The infection with A. hydrophila to T. nilotica was transmitted experimentally by I/P and I/M routes and not transmitted by scarification of the epidermis.
    Crowdness was a major factor for increasing mortalities among inoculated tilapias. Besides, T. nilotica have been proved to be a good model for studying the biological properties of fish pathogenic bacteria.
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  • Teresa P. NIETO, M. J. R. CORCOBADO, Alicia E. TORANZO, Juan L. BARJA
    1985 Volume 20 Issue 2-3 Pages 99-105
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    We have studied two epizootic outbreaks occurred in March, 1983 and April, 1984, in fingerling rainbow trout of about 4 cm length reared in freshwater at North-West of Spain. A total of 84 strains were isolated from peritoneal cavity, liver, kidney and gills of diseased fish and were assigned to five main bacterial groups : Aeromonas, Flavobacterium-Cytophaga, Pseudomonas-Xanthomonas, Gram positive Cocci and Enterobacteria. All these bacterial groups were present in the peritoneal cavity, kidney and gills, whereas Pseudomonas-Xanthomonas and Gram (+) Cocci were not recovered from liver. Aeromonas (50%) and Flavobacterium-Cytophaga (15.6%) were the prevalent groups in the peritoneal cavity, being also detected in high percentage in kidney and gills. The majority of the Aeromonas strains belonged to the motile Aeromonas group, and were further classified to the species level.
    Most of the Aeromonas strains resulted to be pathogenic for rainbow trout. Four representative strains were tested for LD50 values and included in the “virulent” (LD50≤104.5) or “weakly virulent” (LD50 = 105.5) categories. These strains produced gas from glucose, were VP positive and fermented salicine, being assigned to the A. hydrophila species, and three of them shared the characteristics of the ideal phenotype of A. hydrophila biovar hydrophila displaying a strong elastase and staphylolytic activities.
    The analysis of physico-chemical and bacteriological parameters of the water, revealed that both epizootics appeared to be “stress” mediated since the mortalities occurred when the temperature of water suddenly increased from 5.5-8°C to more than 11°C. Then, our data confirm that motile Aeromonas septicemia is usually enhanced by elevations of water temperature.
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  • Tadatoshi KITAO, Terutoyo YOSHIDA, Takashi AOKI, Mikio FUKUDOME
    1985 Volume 20 Issue 2-3 Pages 107-114
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A comparison of the biochemical and serological characteristics of atypical Aeromonas salmonicida strains isolated from eel (Anguilla japonica), goldfish (Carrassius auratus), and reference strains of A. salmonicida were reinvestigated.
    The biochemical and serological properties of causative agents of ulcer disease in eel at Tokushima and Shizuoka prefecture, and Hiroshima University in Japan were similar with isolates previously described. Several biochemical characteristics distinguished the isolates reported here from atypical A. salmonicida strains from goldfish, eel, and typical A. salmonicida.
    The DNA base composition (mol% guanine plus cytosine) of the isolate was similar with those of some atypical and typical A. salmonicida previously described.
    The thermostable antigenic structure of atypical and typical A. salmonicida were similar to the isolate reported here. The thermolabile antigenic structures showed some differences among the strains.
    The structure of lipopolysaccharide (LPS) from all strains demonstrated identical pattern by electrophoretic analysis.
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  • R.C. DUREMDEZ, G.D. LIO-PO
    1985 Volume 20 Issue 2-3 Pages 115-123
    Published: September 05, 1985
    Released: October 26, 2009
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    Identification and examination of the physiological characteristics of Pseudomonas sp. isolated from fry of Sarotherodon niloticus (L.) was conducted. Based on morphological and biochemical tests, the bacterium was identified to be a strain closest to Pseudomonas fluorescens. In vitro physiological growth patterns at varying temperatures, NaCl concentrations, and pH were observed for a maximum of eleven days incubation while growth of the test bacterium into various water media were observed for a maximum of 148 days. Bacterial growth occurred between 10° to 41°C with optimum growth at 25 to 30°C. The bacterium tolerated NaCl concentrations of 0 to 50 ppt. Optimum growth, however, was obtained from 0 to 15 ppt. It was found that growth was possible only at pH 5.0 to 9.7. Optimum growth occurred at pH ranging from 5.7 to 8.4. Inoculation of the test bacterium into different freshwater media obtained from various sources resulted in growth and rapid multiplication. Viability was maintained throughout the 148 days incubation period. Growth in the brackishwater medium was observed only until 50 days. No growth was observed in the seawater medium.
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  • K. Olav HOLM, Ellen STROM, Klara STENSVAG, Jan RAA, Trond JORGENSEN
    1985 Volume 20 Issue 2-3 Pages 125-129
    Published: September 05, 1985
    Released: October 26, 2009
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    A Vibrio shaped bacterium has been isolated from nephric tissues of moribund atlantic salmon suffering from the socalled “Hitra disease”. Eighteen isolates of this bacterium, from geographically distant fish farms all along the Norwegian coast, were shown to be very similar in biochemical properties. Serotyping and DNA finger-printing provided additional evidence for similarity between the isolates and that they clearly differ from Vibrio anguillarum and Vibrio ordalii.
    The particular Vibrio associated with the “Hitra disease” has been designated Vibrio sp. TEO, and is assumed to be involved in the disease development. The bacterium has not been found in any healthy fish, even in farms with outbreaks of “Hitra disease”. The Vibrio sp. TEO elicited disease with similar symptoms when injected into healthy fish, and the same bacterium could be reisolated.
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  • Kenichi TAJIMA, Yoshio EZURA, Takahisa KIMURA
    1985 Volume 20 Issue 2-3 Pages 131-142
    Published: September 05, 1985
    Released: October 26, 2009
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    Taxonomic studies were performed on two hundred nineteen bacterial isolates from eleven species of fish affected by vibriosis reared in fresh water or sea water all over Japan. First, we tried to identify these strains according to Bergey's Manual, 8th ed. (1974). Vibrio anguillarum and related organisms, accounting for about 90% of the strains tested, were confirmed to be causative organisms of vibriosis. Then we attempted to clarify the relationship of these organisms by numerical taxonomy with 103 representative strains. Eighty-nine of the 103 strains were classified into five major taxons (phenon I-V) with similarities of ≥ 80%. Phenon I was comprised of 64 strains identified as V. anguillarum. Phenon II contained 16 strains of Vibrio sp. (corresponding to V. ordalii by SCHIEWE et al., 1981). All of the organisms in phenon II were isolated from salmonidae reared in fresh water. Phenons III and IV consisted of the two reference strains of V. metschnikovii and five of V. parahaemolyticus, respectively. Phenon V contained two strains which were isolated from the anchovy (Eugraulis japonica) and the yellowtail (Seriola quinqueradiata). Fourteen single member-clusters belonged to other species or genera. Next, we examined the DNA-DNA homology among representative strains of each phenon, and between the five phenons and the six single member-clusters. From the results, we confirmed that phenons I and II differed from phenons III, IV, V and the single member-clusters. According to the numerical taxonomy, we considered phenon I to be clearly different from phenon II with similarities of less than 57%; however, the results of the DNA-DNA homology indicated that the two phenons probably belonged to the same species. Subsequently, we carried out a serological analysis of thermostable and thermolabile antigens of the V. anguillarum of phenon I and phenon II with additional isolates. The results showed that with thermostable antigens V. anguillarum could be separated into eight serological groups (J-O-1-J-O-8). However, more than 90% of them were classified as J-O-1-J-O-3. Furthermore 80% of the strains belonging to J-O-1 were isolated from fish reared in fresh water and more than 80% of the strains in J-O-3 were isolated from fish reared in sea water. The sources of the strains belonging to J-O-2 were not specified. There was only one strain belonging to each of J-O-4, J-O-5, J-O-6 and J-O-7, but all of them were isolated from diseased fish. So these strains are worthy of notice in relation diagnosis and prevention against fish vibriosis in Japan. The strains belonging to J-O-8 were isolated from the sea environment only, and were only slightly virulent. Their existence in the fish culture environments is interesting in regard to the epidemiology of fish vibriosis. The V. anguillarum of phenon II, which were all isolated from salmonidae reared in fresh water, possessed a common thermostable antigen (J-O-1) with the V. anguillarum of phenon I. Therefore they could not be distinguished from the V. anguillarum of phenon I by serotyping using the thermostable antigen. However, we found that they could be distinguished by a thermolabile antigen. We also found that all of the V. anguillarum (phenons I and II) possessed a common thermolabile antigen.
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  • Ming-Chen TUNG, Shinn-Shyong TSAI, Lih-Fang HO, Shiuh-Tyan HUANG, Shin ...
    1985 Volume 20 Issue 2-3 Pages 143-148
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    In March 1983, an acute bacterial septicemic infection in fresh water pond-cultured Formosa snakehead fish (Channa maculata Lacepede) outbroke in Pingtung Hsein, Taiwan. The affected fish showed no apparent surface lesions, nevertheless, sudden listlessness and subsequent death at the bottom of the pond were the only clinical feature of the epizootic. The accumulative mortality was as high as 30% (1, 500/5, 000). The characteristic bipolarity of bacilli in blood and squash smear of spleen were recognized. Lesions of white, circumscribed areas were scattered throughout the parenchyma of spleen and kidney. Histologically, the acute focal necrosis with various sizes of bacterial clumps were apparent. Based on the growth characters, morphological and biochemical properties of the isolated bacterium, it was classified into the genus Pasteurella. The isolate was sensitive to the most antimicrobial agents tested, and the epizootic was effectively controlled by the medication with chloramphenicol.
    The 50% lethal dose of Formosa snake-head fish to this Pasteurella isolate was 101.9 CFU/ml which indicates the bacterium is highly pathogenic to this particular fish species. The lesions similar to the natural cases were produced together with re-isolation of the inoculated bacterium from the experimentally infected fish.
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  • R. G. GETCHELL, J. S. ROHOVEC, J. L. FRYER
    1985 Volume 20 Issue 2-3 Pages 149-159
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Antigens of seven isolates of Renibacterium salmoninarum were compared serologically using immunoelectrophoretic techniques. Seven common components were identified by their electrophoretic mobilities in each antigenic profile. One of these common components designated antigen F, was partially purified by ammonium sulfate precipitation and gel filtration. Cross adsorption analysis showed antigen F to be the major surface antigen of R. salmoninarum. This antigen was heat stable and its molecular weight was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 57, 000.
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  • Hisatsugu WAKABAYASHI, Toshiyuki IWADO
    1985 Volume 20 Issue 2-3 Pages 161-165
    Published: September 05, 1985
    Released: October 26, 2009
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    To test the hypothesis that mortality of bacterial gill disease (BGD) is related to tissue hypoxia, changes in glycogen, pyruvate and lactate concentrations in muscle tissue of juvenile rainbow trout with BGD were determined. The muscle levels of glycogen and lactate in fish infected experimentally with Flavobacterium sp. BGD 7721 (ATCC 35035) showed a progressive decline following infection. This was interpreted as reflection of the fact that the infected fish were listless and did not take food. Muscle lactate concentration reached the lowest values, 78.6±27.0 mg%, when the experimental fish began to turn sideways, and then rised to 133.0±57.7mg%until they died. The increase in muscle lactate/pyruvate ratio (L/P ratio) at the time of death was more significant than that in muscle lactate. This appeared to reflect the accumulation of “excess lactate” in the muscle.
    We concluded that a breakdown in gas exchange at the gills in the fish with BGD caused the failure in circulation to provide oxygen enough to remove excess lactate from the muscle, even though the level of muscle lactate was not so high as that of healthy fish.
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  • Mitsuru OTOTAKE, Hisatsugu WAKABAYASHI
    1985 Volume 20 Issue 2-3 Pages 167-171
    Published: September 05, 1985
    Released: October 26, 2009
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    The extracellular products (ECP) of Flavobacterium sp. were studied. The ECP were obtained from the strain BGD 7721. (ATCC 35035) cultured on CGY agar. Hemagglutinating activity of the ECP for erythrocytes from several kinds of animals and agglutinating activity for formalin-killed bacterial cells (BGD 7721) were detected. By immersing juvenile rainbow trout in the solution, the ECP induced clubbing of gill filaments and, then, fusing of lamella, which were characteristics of BGD. Protease, phosphatase and phosphoamidase were detected in the ECP, but hemolysin and endotoxin were not. The serological analysis indicated that the ECP had two types of antigen, one specific to itself and the other common to the washed formalin-killed cells.
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  • Hiroshi KODAMA, Mohamed MOUSTAFA, Takeshi MIKAMI, Hisao IZAWA
    1985 Volume 20 Issue 2-3 Pages 173-179
    Published: September 05, 1985
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Extracellular toxic substance of Vibrio anguillarum was partially purified from cell-free culture filtrate of the bacteria. Two fractions (GI and GII + III) obtained by Sephadex G-200 chromatography following DEAE-cellulose chromatography were lethal for rainbow trout and mice. By sodium dodecylsulfate-polyacrylamide gel electrophoresis, GI and GII + III fractions were found to be composed of 2 components each. The components of the GI fraction had molecular weights of 40 K and 34 K, and those of GII + III had molecular weights of 60 K and 37 K. A carbohydrate band was associated with the protein band of 40 K. Findings at necropsy were enterotoxingenicity and peripheral vascular disorder. The toxic substance in the GI fraction was resistant to trypsin, protease, ethyl ether and acetone but was sensitive to potassium periodate. The toxic substance was comparatively thermostable but was inactivated by heating at 100°C or 121°C for 20 minutes. The toxic activity of the GI fraction was completely neutralized by anti-GI rabbit serum.
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  • Mohamed MOUSTAFA, Hiroshi KODAMA, Takeshi MIKAMI, Hisao IZAWA
    1985 Volume 20 Issue 2-3 Pages 181-186
    Published: September 05, 1985
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Culture filtrate of pathogenic Vibrio sp. (strain N7802) was fractionated by DEAE-cellulose ion exchange chromatography. The fraction showing lethal activity in rainbow trout and mice was eluted from the column with linear gradient of NaCl (DII fraction). The first peak (GI fraction) obtained by purification of DII fraction by Sephadex G-200 gel chromatography had lethal toxicity against rainbow trout and mice. Neither protease nor hemolytic activity was observed in the GI fraction. In sodium dodecylsulfate-polyacrylamide disc gel electrophoresis, the GI fraction revealed one protein band with molecular weight of 35 K and one periodic acid-Schiff positive band in the same position as the protein band. These results indicate that Vibrio sp. strain N7802 produced extracellular toxic substance which was distinct from hemolysin or protease and the toxin might play a role in the pathogenesis of vibriosis in rainbow trout.
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  • Fulvio SALATI, Riichi KUSUDA
    1985 Volume 20 Issue 2-3 Pages 187-191
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A chemical analysis of Edwardsiella tarda lipopolysaccharide (LPS) preparation used for immunization of eels was performed. The LPS was prepared by phenol-water extraction followed by purification with Cetavlon and high speed centrifugation. Chemical analysis showed 3.6% protein, 0.09% organic phosphorus, 22.0% sugar and 8.3% fatty acids. The monosaccharide composition was : 4.1% 2-keto-3-deoxyhexose (KDO), 1.1% pentose, 12.0% hexose, 0.6% 6-deoxyhexose, 3.9% heptose and 3.9% aminosugar. The fatty acids were analyzed by gas-liquid chromatography (GLC) as their methyl esters and their identities were confirmed by mass spectrometry. The results of the GLC analysis showed that the principal constituents were β-hydroxymyristic acid, myristic acid and palmitic acid. The similar composition of the fatty acids and the aminosugar, glucose, galactose, heptose and KDO shows a taxonomic correlation between Salmonella and E. tarda. The presence of non-hydroxylated fatty acids may decrease the immunogenicity of the LPS preparation.
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  • Junichiro NOMURA, Takashi AOKI
    1985 Volume 20 Issue 2-3 Pages 193-197
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The lipopolysaccharide (LPS) structures of strains of fish pathogenic bacteria; Vibrio anguillarum, Aeromonas hydrophila, Edwardsiella tarda, E. hoshinae, E. ictaluri, and Pasteurella piscicida, were analyzed by the silver staining method in polyacrylamide gel. The LPS profiles in V. anguillarum had differences depending on the serotyping groups A, B, C, D, E, F, G, H, and I. The LPS of the six strains of serotype A had the same electrophoresis pattern. The LPS structure also differed for the tested strains of A. hydrophila. Five types of LPS profiles were found in Edwardsiella tarda strains. LPS profiles of E. hoshinae and E. ictaluri were differed from those of E. tarda. There were identical LPS structures of Pasteurella piscicida strains isolated elsewhere.
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  • Takashi AOKI, Tetsuya KANAZAWA, Tadatoshi KITAO
    1985 Volume 20 Issue 2-3 Pages 199-208
    Published: September 05, 1985
    Released: October 26, 2009
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    Infection with multiple drug-resistant strains of Vibrio anguillarum was observed in ayu (Plecoglossus altivelis) farms from 1981 to 1983. The strains collected from various areas of Japan showed resistance to various combinations of nine drugs : chloramphenicol (CP), tetracycline (TC), streptomycin (SM), ampicillin (ABPC), colistin, nalidixic acid, furazolidone, sulfamonomethoxine (SA), and trimethoprim (TMP). The detected R plasmids showed resistance to CP, TC, SM, ABPC, SA, and/or TMP. The digestion patterns of the R plasmids were identical. These R plasmids also showed high homology with the R plasmids detected in 1980 as determined by the Southern blot hybridization method. In other words, drug resistant strains of V. anguillarum carrying R plasmids with the same DNA structure have been distributed in ayu farms since 1980 in Japan.
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  • Noriyuki TAKASHIMA, Takashi AOKI, Tadatoshi KITAO
    1985 Volume 20 Issue 2-3 Pages 209-217
    Published: September 05, 1985
    Released: October 26, 2009
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    Two-hundred eighty-one strains of Pasteurella piscicida were collected from cultured yellowtail (Seriola quinqueradiata) in various districts of Japan between 1981 and 1983. Two-hundred sixty-two strains were resistant to combinations of chloramphenicol (CP), tetracycline (TC), ampicillin (APC), kanamycin (KM), nalidixic acid, furazolidone, and/or sulfamonomethoxine (SA). Transferable R plasmids were detected in 168 out of the 262 strains. The most common types of detected R plasmids were those encoded with resistance to CP, TC, and SA, and also those markers containing KM. Fortyone strains carrying APC-resistance had appeared first in 1982, and a transferable R plasmid was also detected for the first time.
    The R plasmids encoded with different resistance markers were constructed from common DNA sequences. Identical digestion patterns were observed in R plasmids detected from various areas. There was strong homology with these R-plasmid DNA. Consequently, the multiple drug-resistant strains of P. piscicida, carrying an R plasmid with the same DNA structure, were distributed in yellowtail culture farms in various areas.
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  • Teruo MIYAZAKI, Noboru KAIGE
    1985 Volume 20 Issue 2-3 Pages 219-227
    Published: September 05, 1985
    Released: October 26, 2009
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    A comparative histopathological study was made on natural infections of Edwardsiella tarda in Japanese flounder; Paralichthys olivaceus, red sea bream; Pagrus major, tilapia; Tilapia nilotica and Japanese eel; Anguilla japonica, and of Edwardsiella ictaluri in channel catfish; Ictalurus punctatus. Histopathological aspects of E. tarda infection of Japanese flounder and Japanese eel, and E. ictaluri infection of channel catfish were commonly characterized by suppurative inflammation in the infected lesions. Histopathological aspects of E. tarda infection of tilapia and red sea bream were commonly characterized by granulomatous inflammation preceded by macrophage infiltration in the infected lesions. As to inflammatory cells, causative bacteria overcame phagocytotic activities of neutraphils and macrophages resulting in intracellular multiplication. However, the number of bacteria was obviously decreased in the granulomas.
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  • Jim S. NELSON, John S. ROHOVEC, John L. FRYER
    1985 Volume 20 Issue 2-3 Pages 229-235
    Published: September 05, 1985
    Released: October 26, 2009
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    Rainbow trout (Salmo gairdneri) were injected intraperitoneally (IP) or waterborne infected with Vibrio anguillarum, strain LS-174. Every three hours for 48 h, three fish were sampled and fixed for histological examination. The progression of the infection and the fate of the invading pathogen was determined by staining sections with anti-V. anguillarum fluorescein-labeled rabbit immunoglobulin G (IgG). The tissue location of the pathogen in IP and waterborne infected fish was similar. In both cases the bacterium was initially sequestered in the spleen. Increase in the numbers of the bacterium occurred in the spleen followed by proliferation into the kidney. Death resulted from bacteremia with most tissues of the fish septic. Extensive necrosis of kidney, spleen, posterior intestine and liver was observed. The gills were congested with microorganisms and the epithelial cells destroyed. Extracellular bacterial antigen was observed in the musculature, kidney, liver, intestine and spleen. No phagocytosis by macrophages was observed.
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  • Hiroshi KODAMA, Akihiko HONDA, Mohamed MOUSTAFA, Takeshi MIKAMI, Hisao ...
    1985 Volume 20 Issue 2-3 Pages 237-242
    Published: September 05, 1985
    Released: October 26, 2009
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    An enzyme-linked immunosorbent assay (ELISA) was developed to detect anti-Aeromonas salmonicida antibody in rainbow trout immunized with the formalin-killed bacteria. Absorbance of the sera in ELISA correlated well with the serum dilutions and the agglutinin titer of each serum. The ELISA titers of the sera were much higher (usually 5 to 40 times) than the titers determined by agglutination test. By ELISA, antibody was detected in 1 out of 4 fish 2 weeks after immunization and in all of the fish 4 weeks after immunization. On the other hand, agglutinin was first detected 4 weeks after immunization. Inoculation of casein into fish before immunization showed immunostimulating effect on antibody production. The ELISA did not detect antibodies against A. hydrophila, A. punctata, A. liquefaciens, Vibrio anguillarum and other species of Vibrio in rainbow trout, whereas extensive cross reactions were observed among these bacteria and A. salmonicida by agglutination test and immunodiffusion.
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  • Mamoru YOSHIMIZU, Takahisa KIMURA
    1985 Volume 20 Issue 2-3 Pages 243-261
    Published: September 05, 1985
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The application of a coagglutination test for the diagnosis of diseases in fish was studied using staphylococci specifically sensitized with antibodies against the bacteria causing bacterial kidney disease (BKD), furunculosis, vibriosis and goldfish ulcer disease, and also against the virus causing infectious pancreatic necrosis (IPN). This method proved to be a simple, rapid and reliable diagnostic test suitable for use in the laboratory or field and requires no special apparatus.
    Procedures for this method are summarized as follows :
    1. The kidney or affected tissue samples from the diseased fish are homogenized in four to nine times their volume of PBS or HANKS' BSS. If the antigen is heat stable, it is also heated in a boiling water bath for 30 min.
    2. The supernatant material is collected after centrifugation at 4000 rpm for 20 min. This may be omitted if a centrifuge is unavailable.
    3. One drop of the supernatant material and one drop of antibody-sensitized staphylococci suspension are mixed on a glass slide and incubated in a wet chamber at room temperature. The slide is examined after 30, 60 and 90 min.
    4. If coagglutination is observed, the infected fish should be examined using another method to confirm the diagnostic results.
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  • Chiu-Yuan CHIEN, Ching-Long LIN
    1985 Volume 20 Issue 2-3 Pages 263-266
    Published: September 05, 1985
    Released: October 26, 2009
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    An observation was made for the developmental morphology of Lagenidium sp. found from pondreared larvae of red shrimp, Penaeus indicus. This fungus, a marine mastigomycete destroyed larvae and gave mortality up to 85% but generally only from antennule, carapace and uropod could be easily examined, and also shown that zoospores completely formed in the filamentous sporangium within the host body and emerged through the orifice of exit tubes. The mycosis of crustaceans is detected while the environmental condition was bad to victims, and reported as new to Taiwan.
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  • Kuo-Chun LIU, Lee-Min MAI, Chau-Heng CHIEN
    1985 Volume 20 Issue 2-3 Pages 267-272
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Branchiomycosis, also known as gill rot disease of fish has occurred in Taiwan among reared eels, Anguilla japonica, in recent years. The presence of the fungal pathogen in the gill tissue was identified under light microscope based on the bead-like structure known as aplanospores produced by the pathogen. The fungal infected gill tissue was processed for electron microscopic study.
    Evidence indicated that the reproductive process of the fungal pathogen started by condensation of the coenocytic cytoplasm and followed by wall formation within the common fungal wall. The newly formed cell walls partitioned the coenocytic cytoplasm. Each part of the partitioned cytoplasm developed into a spherical zoosporangium, used to known as aplanospore. After maturation, the zoosporangia separated from each other and from the common hyphal wall. Many flagellated zoospores were produced from each zoosporangium.
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  • Nobuaki OKAMOTO, Kiyokazu NAKASE, Hiroyuki SUZUKI, Yutaka NAKAI, Kyoji ...
    1985 Volume 20 Issue 2-3 Pages 273-285
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The varied developmental forms of Ichthyophonus hoferi induced in culture including amoeboblasts, amoeboid bodies, plasmodium-like bodies, spherical uni-or binucleate bodies, thick walled spherical multinucleate bodies and spherical multinucleate hyphal terminal bodies that were observed under different cultural conditions are described. When the thick walled spherical multinucleate bodies were seeded into MEM containing 10% fetal bovine serum at pH 7-9, there was minimal hyphal growth following germination, which produced spherical uni-or binucleate bodies subsequently developing into the thick walled spherical multinucleate bodies. At pH 3-5 in the same MEM medium the growth was characterized by abundant hyphal growth and the formation of spherical multinucleate hyphal terminal bodies at the tips of each hypha. These hyphal bodies differed from the original spherical multinucleate bodies in cell wall thickness. However, the spherical multinucleate hyphal terminal bodies produced at pH 3 or 5 could germinate to form more hyphae at these low pH levels but those produced at pH 3 when shifted to a higher pH of 7-9 did not produce hyphae but only formed the plasmodium-like and oval amoeboid bodies. When the spherical multinucleate hyphal terminal bodies were seeded into TGC medium at pH 7, the growth was characterized by production of a thick (15-20μm) and abundant hyphal growth on which were produced identical spherical multinucleate hyphal terminal bodies which had subsequent growth characteristics as those produced in MEM at pH 5. Our observations shows that differences such as the extent and type of hyphal growth and the size and structure of spherical bodies produced reflect the available nutrients and physical conditions such as pH surrounding I. hoferi. The thick walled spherical multinucleate bodies produced in culture is probably identical to the thick walled forms observed in infected fish and described previously by a number of different names such as “resting spore”, “latent cyst”, and “large multinucleate bodies”.
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  • A. AMANDI, R. A. HOLT, J. L. FRYER
    1985 Volume 20 Issue 2-3 Pages 287-304
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The geographic range of Myxobolus insidiosus has been extended to the Aumsville irrigation canal, Aumsville Rearing Ponds, Aumsville Lake and the Coos and Yaquina River Systems in Oregon and a new host, rainbow and steelhead trout (Salmo gairdneri) was identified. Morphometric studies of M. insidiosus from selected hosts and localities indicated that plasmodial and spore variability occur and subspeciation of the parasite is not warranted.
    Parasitism with M. insidiosus was dependent on time of exposure to the infective stage. Coho salmon (Oncorhynchus kisutch) were not infected with M. insidiosus after 8 d exposure but were parasitized when exposed for 50 d. Infection also depended on the number of infectious units believed present in the water supply. All chinook salmon (Oncorhynchus tshawytscha) in the Aumsville Rearing Ponds became parasitized, whereas only 10% of those exposed in a McKenzie River power canal were infected.
    Development of M. insidiosus in chinook salmon reared in 12°C pathogen-free water was similar to that reported for other myxosporidans. The parasite was found only in the white muscle bundles of these fish. A host response characterized by enlarged plasmodia infiltrated with host cells occurred only against mature parasite stages. Appearance of new trophozoites 120 d after exposure may represent autoinfection.
    Serum specific for M. insidiosus or Ceratomyxa shasta did not react with uninfected salmonid tissues or with spores of other Pacific Northwest myxosporidans when tested by the gel-diffusion technique. Similar tests indicated that M. insidiosus obtained from various host species collected throughout the known geographic range of the parasite were antigenically related. Trophozoite and spore stages of M. insidiosus and C. shasta were detected by immunofluorescence. Using this technique no cross reactions were noted between C. shasta antisera and M. insidiosus, Henneguya salminicola, Myxosoma squamalis, or Myxosoma cerebralis spores. Fluorescence did occur between M. insidiosus antiserum and M.cerebralis spores.
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  • Chu-Fang LO, Shih-Chieh CHEN, Chung-Hsiung WANG
    1985 Volume 20 Issue 2-3 Pages 305-312
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Microscpopically, the metacercariae of Clinostomum complanatum were encapsulated by a fibrous layer to form a cyst. The cyst wall was composed of connective tissue fibers, chiefly collagen fibers, of the fish in reaction to the infection. There were blood vessels penetrating into the cyst wall and forming a capillary network. These blood vessels might supply the nutritional requirements of the metacercaria and remove the wastes produced by the worms.
    The metacercaria of C. complanatum got a lot of nutrients from its host for growth and storage. The possible routes of the metacercaria of C. complanatum to get nutrients from its host may be through the digestive tract or by the direct absorption of the covering of the worm from the body fluid of the fish. The morphological feature suggested that the tegument of the metacercaria of C. complanatum possessed the tegumental absorption function.
    Generally, the metacercariae of C. complanatum lay quiescently in the cyst. No great harm was done to fish unless there were massive numbers. The greatest damage occurred when metacercariae had been activated and migrated out of the body wall of the fish. The process of the excystment and migration of the worms caused the congestion and hemorrhage followed by the serious tissue damage. After the excystment of the metacercaria, the fish tissues around the worm were dissolved. The result indicated that the worm might produce certain enzymes to facilitate the dissolution of fish tissues and cause the death of the fish due to the destruction of the fish body.
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  • Kazuya NAGASAWA
    1985 Volume 20 Issue 2-3 Pages 313-321
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A shipboard survey was undertaken to determine the prevalence of visceral adhesions in sockeye salmon, Oncorhynchus nerka, in the central North Pacific Ocean in the spring and early summer of 1981-1983. Of 3, 935 sockeye from 49 locations examined, 206 (5.2%) were affected. Although no adhesions were observed in fish less than 30 cm in fork length, prevalence increased in medium-sized fish. Visceral adhesions were most common among fish between 35 and 49 cm. In fish above 50 cm, however, the proportion of affected fish decreased with increasing fish size. No adhesions occurred in fish of 65 cm and larger.
    A close relationship between prevalence and fish age was noted. Prevalence increased steadily with increasing freshwater age (0-winter, 0%; 1-winter, 4.1%; 2-winter, 6.3%;3-winter, 11.0%). As to ocean age, prevalence was highest (6.9%) in fish which had spent two winters at sea, but was at a low level in fish of each of other ages (1-winter, 1.4%;3-winter, 1.2%; 4-winter, 0%).
    The percentage of affected fish was higher in males (7.9%) than in females (2.7%). This was stable among years and most fishing locations. Adhesions also occurred most often in immature fish (male, 9.4%; female, 4.2%). With developing fish maturation, prevalence decreased and reached null in both sexes when fish were mature.
    Prevalence varied latitudinally, declining from south to north in general. This was reflected by latitudinal changes in the size and maturity compositions of fish. In the areas between 42° and 47°N, most catches consisted of immature medium-sized fish, in which adhesions were often observed. In the areas between 48° and 51°N, however, fish were large and maturing, and adhesions were rarely found in them.
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  • Da-Shu NIE, Jin-Pei PAN
    1985 Volume 20 Issue 2-3 Pages 323-330
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A review is briefly made for the research on the diseases of grass carp from 1953 to 1983 in China. Grass carp which is one of the four famous Chinese “farm fish” is particularly important freshwater fish in China. However, it is most susceptible to various kinds of diseases so far we know in China. The pathogens included viruses, bacteria, fungi, protozoan, worms, crustaceans, algae and larvae of molluscs. Besides, some kinds of diseases were cuased by non-living factors. For the widely epidemical diseases, they have been studied on etiology, epidemiology and prevention and cure. Some good results for controlling most of these diseases have been obtained. For preventive culture of grass carp, comprehensive measures of technical management were applied. Recently, we have found that hygenic surrounding like rice fields are good places to prevent grass carp's diseases, in the meantime the weed eating grass carp helps rice plant to preserve the energy wasted by the weeds. A mutural relationship between rice plant and grass carp has well been established recently in China. Extensive works were carried out for the investigation of parasites of grass carp. 127 species of parasites have been discovered from this kind of fish, among them 73 were new species and two new families were suggested.
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  • Ya-Li HSU, H.M. ENGELKING, J.C. LEONG
    1985 Volume 20 Issue 2-3 Pages 331-338
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The structural polypeptides of the Round Butte strain of infectious hematopoietic necrosis virus (IHNV) were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and stained with silver nitrate. Five virion proteins were identified. The relative contribution of each protein species to the total protein content of the virus was determined. An approximation of the number of molecules of each protein per virion was calculated.
    The time of the intracellular appearance for each virion protein of IHNV was investigated during the infection cycle. The first protein for IHNV to appear in the course of infection was the N protein, at 2-3 h after infection. At 6-7 h after infection, the membrane proteins, M1 and M2, could be identified in the autoradiograms. The two forms of the glycoprotein, G1 and G2, were found at 9-10 h after infection. The results from both pulse and pulse-chase labeling experiments suggest that G2 is synthesized immediately and then is further glycosylated to form G1. Since cellular protein synthesis was not inhibited during early infection, it was difficult to distinguish the viral L protein from host protein in the early samples. The temporal synthesis of the viral polypeptides suggests that those polypeptides are the translation products of independently transcribed monocistronic mRNA.
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  • C. L. SCHULTZ, B. C. LIDGERDING, P. E. MCALLISTER, F. M. HETRICK
    1985 Volume 20 Issue 2-3 Pages 339-341
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A hybridoma cell line that continually secretes antibody against infectious hematopoietic necrosis virus was developed and designated M-IHNV-W1. Antibodies in culture fluids were concentrated and purified by Protein A Sepharose CL-4B affinity chromatography. The immunoglobulin was isotyped as IgG 2b with a kappa light chain. The IgG was specific for infectious hematopoietic necrosis virus and had binding activity but low neutralizing activity. Little cross-reactivity occurred with viral hemorrhagic septicemia or infectious pancreatic necrosis viruses.
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  • Masahide HASOBE, Mineo SANEYOSHI
    1985 Volume 20 Issue 2-3 Pages 343-351
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Infectious hematopoietic necrosis virus (IHNV) is well known fish pathogen on salmonid fishes in an aquaculture. In present moment, however, the effective chemotherapy on IHNV infection was not reported so far. We described here the search for new therapeutic agents IHNV infection in vitro and in vivo.
    Firstly, we examined mainly nucleoside analogues as potential virostatic agent using our developed, very simple and quantitative method (namely, CPE spot reduction method) on CHSE-214 cell monolayer. This method could be successfully applied to our screening purpose and gave good results which were comparable to usual plaque reduction method.
    Among the twenty four compounds tested in vitro, we selected eleven effective compounds against IHNV which showed the 50% inhibition of CPE spot within 10 μg/ml and were not observed the cytotoxicity within 10 μg/ml. In this report, we used five compounds such as 9-β-D-ribofuranosyl-6-mercaptopurine (6-thioinosine, 6-TI), 1-β-D-ribofuranosyl-5-hydroxyuracil (5-OHUrd), 1-β-D-ribofuranosyl-1, 2, 4-triazole-3-carboxamide (Virazole), 9-[S]-(2, 3-dihydroxypropyl)adenine ([S]-DHPA) and 7-chloro-4(4-diethylamino-1-methyl-butylamino)-quinoline (Chloroquine).
    Then we extended our experiment to in vivo for further evaluation against experimentally IHNV infected steelhead trout (Salmo gairdnerii) fry by the immersion method. Life span was increased in treated groups, especially in the case of 6-TI and 5-OHUrd treated groups when compared with virus control group. Difference of the effect of compound was observed between the daily treatment and a day interval treatment of 5-OHUrd, but was not shown in the case of 6-TI.
    Additionally we examined the effects of selected compounds on normal cell growth and viral RNA synthesis. Some of the mode of action of compounds will be discussed.
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  • Paul W. RENO, David V. SERREZE, Susan K. HELLYER, Bruce L. NICHOLSON
    1985 Volume 20 Issue 2-3 Pages 353-360
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The effects of viral erythrocytic necrosis (VEN) on clinical blood parameters and erythrocyte metabolism were investigated in Atlantic cod (Gadus morphua) and Atlantic herring (Clupea harengus h.).
    VEN-infected cod and herring exhibited lower hematocrits (HCT) and erythrocyte counts (E) in comparison to uninfected fish. In addition, VEN-infected cod, but not herring, had significantly lower hemoglobin concentrations (HB). No effects on plasma electrolyte or protein concentrations in either species were detected.
    Several metabolic changes were noted in VEN-infected erythrocytes. Infected cod erythrocytes had significantly lower lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PD) activities than erythrocytes from uninfected fish. No alterations in citrate synthetase (CS) activity were observed. No effects on LDH, G-6-PD, or CS activity were detected in VEN-infected herring.
    In VEN-infected cod erythrocytes the ATP levels were decreased approximately 50% compared to uninfected fish. In contrast, VEN infection in herring was associated with an elevation of ATP levels by approximately 33%.
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  • T. YAMAMOTO, R. K. KELLY, D. NIELSEN
    1985 Volume 20 Issue 2-3 Pages 361-372
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Walleye populations in the central region of Canada have been observed to have at least four skin growths that are associated with different virus particles. These include lymphocystis disease, dermal sarcoma, and two different forms of dermal hyperplasia. All of these growths have been observed in walleye populations in a particular spawning run with some individual fish having more than one type of infection. Observations over a period of years indicate that these lesions can be found in the same locality from year to year although the observed incidences may vary.
    The histopathology and ultrastructure of lymphocystis is typical of other lymphocystis in freshwater and marine fishes consisting of grossly hypertrophied cells containing many 260 nm diameter lymphocystis virus particles.
    The dermal sarcoma tumors on gross observation may be confused with lymphocystis since both tumors are large, opaque, white growths often tinged with red. The dermal sarcoma can be readily differentiated on close observation by their smooth appearance in contrast to the typical granular appearance of the enlarged cells of lymphocystis.
    A third skin tumor identified as an epidermal hyperplasia has a clear slime-like appearance with a bluish tint and consists of cells associated with 135 nm retrovirus particles that bud from the cell membrane into the intercellular spaces. These virus particles in contrast to those of dermal sarcoma virus are fewer in number and not found within cytoplasmic vacuoles.
    A fourth dermal lesion, which in appearance is not unlike that of the retrovirus associated dermal hyperplasia, has a more diffuse character often with swelling of the underlying tissue. This growth is associated with a herpesvirus and is the only virus which has been routinely isolated and propagated in cell culture.
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  • J. R. WINTON, C. N. LANNAN, D. P. RANSOM, J. L. FRYER
    1985 Volume 20 Issue 2-3 Pages 373-380
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    A new virus has been isolated from adult chinook salmon (Oncorhynchus tshawytscha) in the state of Oregon, U.S.A. The virus was recovered from pooled kidney and spleen tissue samples using CHSE-214 cells. Cytopathic effect (CPE) required 28 days to develop on primary isolation. The virus replicated in CHSE-214, CHH-1, KO-6, CSE-119 and FHM cells. It had an optimal growth temperature of 18°C and no virus was produced at 24°C or above.
    The virus was stable in minimal essential medium (MEM) at pH 3-11 and replication was not affected in cells incubated with MEM containing 50μg/ml iododeoxyuridine. Infectious virus was recovered from fractions of a CsCl gradient having a density of 1.20 g/cc. The agent was sensitive to chloroform and caused hemagglutination with erythrocytes from several species of fish, mammals and birds.
    Electron microscopy revealed enveloped particles 125-250 nm in diameter containing a coiled nucleocapsid. Electron micrographs of freon-treated preparations showed the extracted nucleocapsid to be a helix 18 nm in diameter and up to 1000 nm in length. Based on morphology and biochemical features, the virus appears to be a member of the Paramyxoviridae.
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  • Tokuo SANO, H. FUKUDA, M. FURUKAWA
    1985 Volume 20 Issue 2-3 Pages 381-388
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    In the present paper, we described the general biological properties and the oncogenicity of Herpesvirus cyprini or cyprinid herpesvirus 1 (CHV) (SANO, et al., 1984) which were isolated from nine papilloma tissues developed on the skin or the caudal fin of Japanese carp.
    The virus size were as follows; envelope diameter 190.4±27.2 nm, projection length 20.5±4.4 nm, capsid diameter 113.4±8.6 nm. This herpesvirus showed good significant growth on FHM and MCT. The virus titer on FHM cells reached more than 105.5 TCID50/ml at 20°C incubation temperature for 14 days. Syncytium formation was not found in these cell lines. Both FHM and EPC cells infected with this virus possessed intranuclear inclusion, Cowdry type A. It occupied a relatively large area revealing rather irregular shape. The virus titer reduction of over 103 TCID50/ml occurred before and after treatment with ether, pH 3, 50°C heating and IUdR.
    A cluster of the virus particles was found inside and outside inclusion body in FHM cells infected with the virus. Virus particles were more numerous in the karyoplasm undergoing karyorrhexis. Budding immature virus particle from the nuclear membrane, as well as released virions in intracellular space, were observed.
    Oncogenicity trial which we performed using common carp revealed grossly tumors on three fish out of ten. These tumor formations occurred more than five months after inoculation at 15.2°C of rearing temperature. The tumor cells induced in Asagi carp inoculated with the virus showed many virus particles in the karyoplasm and the cytoplasm.
    The experimentally induced tumors on common carp and spontaneously-developed tumors on colored carp possessed the property to be desquamated at the natural condition.
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  • Yoshiaki NAGAMURA, Hisatsugu WAKABAYASHI
    1985 Volume 20 Issue 2-3 Pages 389-394
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Glycogen content of neutrophils in the eel which were injected with some extraneous materials such as formalin-killed cells, 2% solution of casein and physiological saline were determined and their locomotion and phagocytosis were also examined. The eel injected with bacteria had the highest content of neutrophil glycogen, ranged from 74.6 μg to 105.9 μg per 107 neutrophils. The values in those injected with 2% solution of casein and physiological saline were 60.1-66.9 μg and about 45 μg, respectively. In the locomotion of the nuetrophils, the neutrophils from the eel injected with 2% solution of casein migrated best, and those from the eel injected with bacteria did in the next place. The bacterial phagocytosis of the neutrophils was examined in vitro in the whole blood. Glycogen-rich neutrophils showed the most remarkable phagocytosis, though the locomotion was not promoted.
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  • Akihiko HONDA, Hiroshi KODAMA, Mohamed MOUSTAFA, Fumitaka YAMADA, Take ...
    1985 Volume 20 Issue 2-3 Pages 395-402
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    To know the host defense mechanism against infection with Vibrio anguillarum in rainbow trout, phagocytic activities of macrophages were examined with those collected from normal fish and fish immunized with formalin-killed V. anguillarum. Opsonic activity with specific antibody and complement was also investigated. Forty to 50% of the macrophages of peritoneum, pronephron and peripheral blood phagocytosed latex particles. The phagocytosis of V. anguillarum by normal peritoneal macrophages was enhanced in the presence of antibody and complement. Enhanced opsonization was also observed after treatment of either macrophages or bacteria with antibody. In rainbow trout immunized with V. anguillarum, phagocytic activity of macrophages increased significantly 5 weeks after immunization as compared to the activity of macrophages from normal fish. The agglutinin titers increased 3 weeks after immunization. However, bactericidal activity of antibody and complement was not detected in the present experiment. All 8 rainbow trout were protected from infection with the bacteria 5 weeks after immunization and 7 out of 10 fish challenged 1 week after immunization survived. These results indicate that immunized fish were able to develop protective immunity against Vibrio infection before significant levels of antibody or phagocytic activity become detectable.
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  • Stephen G. NEWMAN, John J. MAJNARICH
    1985 Volume 20 Issue 2-3 Pages 403-411
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Furunculosis is a severe, profit limiting disease affecting a wide variety of commercially reared fish species throughout the world. The etiologic agent, Aeromonas salmonicida, produces several potential virulence factors and has some interesting biochemical characteristics that make it a difficult organism to produce an effective vaccine against. A vaccine was prepared using an auto aggregating highly virulent strain of A. salmonicida. This strain was grown by continuous culture fermentation, centrifuged, washed and treated with 5 mM EDTA at an elevated pH. This preparation was used to vaccinate fish.
    Rainbow and brook trout and Atlantic salmon were immunized by injection or immersion with and without a hyperosmotic infiltration treatment. A dose related response was noted when the bacterin was injected. In juvenile brook trout, at a 1 : 5 dilution, 44% died due to A. salmonicida infection after challenge; at a 1 : 10 dilution, 67% died whereas 97% of the control, sham vaccinated fish died. Protection by immersion without a hyperosmotic infiltration treatment was variable with the greatest degree of protection occurring in fish immersed twice. In a typical experiment, mortalities among vaccinated fish ranged from 36.7% for fish immunized once at a 1 : 10 dilution to 0% for fish immunized twice at 1 : 10 dilutions two weeks apart. Control mortality was 70%. In fish immunized by immersion in a 1 : 5 diluted suspension of this bacterin and a concurrent 5% NaCl hyperosmotic treatment, substantial protection was apparent. In a typical experiment mortalities ranged from 7.4% to 22.2% for the vaccinates with control mortalities of 72.7%. It is apparent from this work that successful immersion immunization for the prevention of furunculosis is possible.
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  • Kenji KAWAI, Riichik KUSUDA
    1985 Volume 20 Issue 2-3 Pages 413-419
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The efficacy of oral bacterin to control vibriosis was determined using pond cultured ayu (Plecoglossus altivelis). A formalin-killed whole cell bacterin of Vibrio anguillarum was fed to 322, 000 ayu in seven ponds eight to fifteen times at doses ranging from 0.08 to 0.16g bacterin/kg fish/day. Fish were exposed to natural infections due to vibriosis in the farm ponds. Experimental challenge was performed with fish lots where natural infection did not occur. Natural infection occurred in three ponds of vaccinated fish and three control ponds where bacterin was not fed. A decrease in the number of dead fish and the number of days of medication using oxolinic acid was shown in all of the vaccinated lots as compared to the non-vaccinated lots. Efficacy of the bacterin was assessed as the differences in the mortality profile and the need for medication during two months. The results of the experimental challenge showed the efficacy for more than 59 days. Combined use of oxolinic acid and bacterin did not reduce the efficacy of the bacterin. The smallest amount of bacterin yielding protection was eight feedings of 0.1 g/kg fish on alternate days. The total amount of bacterin required to vaccinate 322, 000 fish was approximately 1.4 kg equivalent to 4.3 mg/fish. The vibrio bacterin delivered by the oral route was shown to be highly effective when given to large commercial ayu populations showing ease in application and reduced stress for the fish.
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  • Yutaka FUKUDA, Riichi KUSUDA
    1985 Volume 20 Issue 2-3 Pages 421-425
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    The efficacy of different vaccine preparations was investigated for the development of a practical vaccine against pseudotuberculosis in cultured yellowtail. The vaccines were : formalin killed Pasteurella piscicida, a whole cell vaccine; phenol-water extracted lipopolysaccharide (LPS), a LPS vaccine; and an autolysed centrifuged 75% (NH4) 2SO4 precipitated culture, a precipitated vaccine. The vaccines were delivered by immersion and spray methods. An artificial challenge by gastral administration with virulent P. piscicida was carried out three weeks after vaccination. The percent survival ten days after challenge in the fish vaccinated by the immersion method were : 87% in group administered the LPS vaccine, 73% using the precipitated vaccine, 40% using the whole cell vaccine and 40% in the nonvaccinated controls. The percent survival ten days after challenge in the fish vaccinated by the spray method were : 80% in the group administered the LPS vaccine, 60% in the precipitated vaccine group, 50% in the whole cell vaccine group and 30% in the non-vaccinated controls. Prior to challenge, higher agglutinating antibody titers against P. piscicida in the skin mucus were observed in vaccinated fish that had greater protection after challenge. It was concluded the LPS from P. piscicida cells was the most effective vaccine of the three vaccines examined against pseudotuberculosis in yellowtail
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  • W.D. PATERSON, S. P. LALL, D. AIRDRIE, P. GREER, G. GREENHAM, M. POY
    1985 Volume 20 Issue 2-3 Pages 427-434
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Experiments were conducted to investigate vaccination and dietary modification as possible prophylactic measures to minimize bacterial kidney disease (BKD) infection occurrence and severity in Atlantic Salmon. In the nutritional modification studies, a commercial diet and six diets containing various levels of calcium, magnesium, zinc, iron, copper, maganese, cobalt, iodine, and fluorine were fed to post-yearling Atlantic salmon. After administration of different diets, the fish fed the diet high in iodine (4.5 mg/kg feed) and fluorine (4.5 mg/kg) had a lower prevalence of clinical BKD (3.6%) as compared to fish fed the other experimental diets (15-24% BKD prevalence) and the commercial feed (34%). In vaccination trials, post-yearling Atlantic salmon parr administered a 0.1 ml intraperitoneal injection of formalin killed BKD cells emulsified in Freund's complete adjuvant, showed an elevated agglutinating antibody response, and almost complete absence of BKD lesion formation in kidneys.
    Prevention of furunculosis was achieved in salmon and trout by vaccination. Injection administration of Aqua Health's “Furogen” a commercial furunculosis bacterin reduced losses from 75-83% in control animals to 2.2-10% in vaccinated fish during laboratory trials. Field evaluation of this bacterin in brook trout demonstrated reduced mortality from 36.1% in controls to 9.7% in vaccinated animals.
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  • Teiichi NISHIMURA, Haruo SASAKI, Munehiro USHIYAMA, Kiyoshi INOUE, Yus ...
    1985 Volume 20 Issue 2-3 Pages 435-443
    Published: September 05, 1985
    Released: October 26, 2009
    JOURNALS FREE ACCESS
    Infectious hematopoietic necrosis virus (IHNV) was formalin inactivated and assayed for immunogenicity in rainbow trout (Salmo gairdneri) delivering the immunogen by intraperitoneal (IP) injection or immersion then challenging with virulent virus by IP injection or waterborne route. Concentrated virus incubated with 0.2% formalin for 6 days at 4°C was found to be inactivated with a high immunogenicity. Using this preparation, IP delivered immunogen showed protection one week after delivery (5.2°C) and persisted for at least 56 days at 5.4°C and 70 days at 11.5°C. A medium to maintain immunogenicity after storage was not found. The IHNV immediately after inactivation was the most effective immunogen. Inactivated IHNV delivered by immersion showed significant immunity as compared to non-immunized trout after waterborne challenge.
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