摘要:

Abstract.A formalized bacterin ofVibrio anguillarum, with and without alum adjuvant, was administered intraperitoneally to rainbow trout under farm conditions. Compared with the normal bacterin the adjuvanted preparation caused pathological changes indicative of chronic peritonitis, substantial early mortalities in 3 cm fish, and to a lesser extent in 20 cm fish, and depressed growth rate. No additional degree of protection against artificial challenge was obtained from its use.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00911.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The efficacy of the immersion method of vaccination was evaluated usingAeromonas salmonicidabacterin. 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.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00912.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The histopathology associated with naturally acquired vibriosis in chum salmon,Oncorhynchus keta(Walbaum), fingerlings caused byVibrio anguillarumwas compared with that caused by infection withVibrio ordalii.Pathogenesis of the two forms was found to be different. Bacteraemia caused byV. anguillarumoccurred in the early stages with pronounced histopathological changes in blood, loose connective tissue, kidney, spleen, gills and posterior gastrointestinal tract. Bacterial cells appeared uniformly dispersed throughout the affected tissues but were most abundant in the blood. WithV. ordalii, bacteraemia developed only in late stages of the disease and the concentration of bacterial cells per ml of blood was less than in theV. anguillaruminfection by a factor of 102–103. Tissues with most pronounced changes were skeletal and cardiac muscle, anterior and posterior gastrointestinal tract and the gills.Vibrio ordaliiobserved in the tissues was not evenly dispersed but was present within tissue as colonies or aggregates of cells. The differences in pathology observed in naturally infected chum salmon were produced experimentally with each pathogen by waterborne exposure of chum; coho,Oncorhynchus kisutch(Walbaum); and chinook salmon,Oncorhynchus tshawytscha(Walbaum). Severe decreases in circulating leucocytes accompanied bacteraemia caused by either bacterial specie

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00913.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Broth filtrate of aVibriospecies, isolated from spontaneously occurring epizootics among cultured oyster larvae,Crassostrea virginica(Gmelin), was shown to contain an exotoxin. Bioassays demonstrated that LC50value was less than 46.6 μg of toxin/l culture of oyster embryos. This quantity was produced by 2.9 × 109colony‐forming units. Purified toxin showed neither proteolytic nor amylase activity; it did, however, demonstrate bacteriostatic capability. Studies showed that the toxin was heat‐labile and that exposure to heat‐produced toxoid had a beneficial effect on oyster embryonic development. Data revealed that although toxin was inactivated by heating, the bacteriostatic capability of the metabolite was not lost. Molecular weight of the toxin was estimated to b

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00914.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

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 a

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00915.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Epitheliocystis infections in the gills of carp from Israel and Portugal occurred in lining epithelial cells as well as mucus and chloride cells. Ultrastructural studies of infected cells revealed several morphological forms of epitheliocystis showing the existence of a pleomorphic developmental cycle. The following stages were observed: chlamydia‐like round cells (RC), non‐dividing round cells (NRC) and bullet‐shaped small cells (SC). All these were identical in shape to RC and SC described from epitheliocystis of other fish, The rickettsia‐like cells (PLC and ILC) which occur in epitheliocystis from other fish species and produce the SC were absent in carp epitheliocystis and instead the RC were seen transforming into SC. Transformation to SC, however, occurred at any stage of the developmental process, even before the replication potential of the RC was exhausted, i.e. before reaching the NR

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00916.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.A vaccine solution of a formalin‐killed culture ofVibrio anguillarumcells was observed to be toxic to young ayu when administered by the hyperosmotic infiltration method. The toxin was present in the culture broth. After the toxin was removed from the broth by centrifugation, the fish were dipped in 5.32% NaCl solution for 2 min and then in a solution containing precipitated cells for 3 min. The immunized fish were protected against vibriosis when challenged one month after immersion. The bacterin was administered to ayu by a further two methods, both using lyophilized whole cells of formalin‐killedV. anguillarum.In one method, the fish were placed in a 5.32% NaCl solution for 2 min and then in a solution containing lyophilized cells at 2 g/l of well water for 3 min (two‐step immersion). In the other method, the fish were placed in a 5.32% NaCl solution containing lyophilized cells also at 2 g/l for 3 min (one‐step immersion). A high level of protection against artificial challenge was achieved with either method. No agglutinating antibodies toV. anguillarumwere detected in either the serum or mucus of fish dipped in a vaccine solution, a supernatant, or a precipitated solution, one month after immersion. On the other hand, serum titres were detected in fish vaccinated by injection, although no titres were detected in mucus. LD50values are presented for the virulence of theV. anguillarumstrain. Compared to the original strain, virulence increased after the third passage in ayu, but decreased after the thirteenth passage in

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00917.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

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 exposu

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00918.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00919.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1984.tb00920.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY