摘要:

Abstract.These studies were done to determine the prevalence of infection, over time, of progeny from a population of 1988 year class brook trout,Salvelinus fontinalis(Mitchill), that was asymptomatically infected withRenibacterium salmoninarum, the causative agent of bacterial kidney disease. This population and its progeny from the 1991 and 1992 spawnings were monitored for approximately 3 years for prevalence ofR. salmoninarumand development of bacterial kidney disease. Ovarian fluid samples from the 1991 and 1992 spawnings, and from a 1993 spawning of the 1991 progeny, were analysed forR. salmoninarumby enzyme linked immunosorbent assay (ELISA) and the membrane filtration fluorescent antibody technique. Kidney and spleen tissues of the 1988 year class were assayed by ELISA following the 1992 spawning. The progeny of the 1991 and 1992 spawnings were followed for increased prevalence ofR. salmoninarumby the ELISA. Kidney tissues were assayed and sampling began once the fish were large enough. Each population of progeny was sampled quarterly for one year. Overall, the progeny displayed decreasing prevalenceof R. salmoninarumand all ovarian fluids of the 1991 progeny (in 1993) were negative. Brood fish and progeny remained asymptomatic during the course of the study.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00330.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Loxothylacus ihlei, a rhizocephalan parasite of the mud crab,Scylla serrata(Forskål), is reported for the first time in Australian waters. The parasite is described and found to be variable in a number of characters. Most infectedS. serrata, collected from commercial catches in the Northern Territory, Australia, were significantly smaller than uninfected crabs, and their abdominal flaps were relatively larger than those of mature females. Annual prevalence of infection was low (2.1%), with the monthly variation ranging from negligible early in the year to around 7% in November

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00331.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Groups of channel catfish,Ictalurus punctatus(Rafinesque). were administeredEdwardsiella ictaluritwice in the form of whole outer membrane proteins (OMP) or heat‐inactivated whole bacteria (IWB) orally or IWB intraperitoneally. Antibody titres and lysozyme concentrations were determined in serum, mucus, gut contents and gut washings taken 7, 14, 21 and 28 days after the second antigen administration. Bacterial killing by anterior kidney neutrophils was determined 7, 14 and 21 days after the second antigen administration. Enhanced killing of tumour targets by nonspecific cytotoxic cells (NCC) was determined 7 days after the second antigen administration. Serum antibody titres of all treatment groups were significantly increased above those of the control group throughout all sampling periods. Fish receiving oral administration of OMP or IWB exhibited maximum serum antibody titres on day 21 or 28. Antibody titres were also detected in mucus, gut washings and gut contents, but did not reach the level of those in the serum. Bacterial killing was significantly increased only on day 7, and could not be correlated to antibody titre or lysozyme concentration. Bacterial killing was found to be the result of a heat‐labile serum factor. NCC activity of fish vaccinated with IWB orally was significantly higher than that of fish vaccinated with OMP orally or controls. Although intraperitoneal vaccination consistently produces higher titre antisera, the results of this study support the idea that oral vaccination can induce antibody systhe

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00332.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.The effects of phosphate and tris buffers on the gill structure of common carp,Cyprinus carpioL, and rainbow trout,Oncorhynchus mykiss(Walbaum), were investigated. Common carp maintained in phosphate‐buffered (a combination of sodium di‐hydrogen phosphate and di‐sodium hydrogen phosphate at a final concentration of 0.01m) standard dilution water for a period of 8 days developed severe pathological changes in the gill tissues, while carp maintained in tris‐buffered (0.01m) dilution water and trout subjected to either of these buffers showed no such changes. Histological changes in the gills of carp exposed to phosphate buffered dilution water included an extensive mucous cell proliferation on the lamellar and filarnental epithelium, and an increased infiltration of eosinophilic granular cells into the gill tissues. A moderate epithelial hyperplasia and an increase in the chloride cell densities on the gill epithelia were also noted. The implications of these findings on the widely accepted practice of the use of phosphate salts and various other buffers in pH control of experimental water are high

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00333.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Since 1992, frequent erythrocytic viral infections have occurred in cultured turbot,Scophthalmus maximus(L.), on several fish farms in Galicia, Spain, causing important mortalities. Affected fish showed haemorrhages in the head, mouth and fins, exophthalmia and abdominal distension. The disease was also characterized by the presence of pale blue inclusions in affected erythrocytes. The examination of these erythrocytes by electron microscopy showed virus particles of 50–160 nm in size in the cytoplasm, budding av the cell membrane and extracellularly. The histopathological study revealed occasional necrosis of kidney haematopoietic tissue, an increase in the size and number of melanomacrophage centres of the spleen and kidney, and oedematous areas with hepatocytes containing eosinophilc bodies in the liver. Degeneration of muscle fibres was accompanied by an intense inflammatory oedema. Dermatitis as well as uveitis and corneal oedema were consistent lesion

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00334.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Interaction ofAeromonas hydrophilaand tilapia,Oreochromis aureus(Steindachner), phagocytes was studiedin vitro.All virulent and avirulent strains of A.hydrophilatested could multiply in non‐activated and Freund's complete adjuvant activated phagocytes. Activated phagocytes increased the uptake of bacteria into cells, and the rates of intracellular replication for these bacteria were faster than in non‐activated phagocytes. Among theA. hydrophilastrains examined, virulent strain PPD134/91 replicated at the fastest rate inside phagocytic cells and produced cytopathic effect in the phagocytes in the shortest incubation time. Opsonized avirulentA. hydrophilawere sensitive to phagocyte‐mediated killing or unable to grow in phagocytes. Serum components and phagocytes may together prevent the growth of avirulentA. hydrophilain fish. The release of extracellular oxygen radicals during phagocytosis was examined using chemiluminescence assay (CL). Virulent strains induced CL responses but avirulent strains did not. This suggests that the virulent strains interacted with the phagocytes somewhat differently from the avirulent st

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00335.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract.Adult brook trout,Salvelinus fontinalis(Mitchill), mounted a strong humoral immune response after injection with inactivated infectious pancreatic necrosis virus (IPNV) in Freund's complete adjuvant (FCA). However, this immunization did not prevent the fish from becoming IPNV carriers. After an injection challenge with virulent IPNV, the immunized and control fish (FCA or water) shed virus in the faeces and reproductive products and had IPNV‐infected leucocytes and visceral organs. Initially, from 1 to 3 weeks post‐challenge (wpc), immunized fish had a lower prevalence of infection and virus titres in the plasma, and fewer infected leucocytes than the control fish. Immunization did not prevent the eventual infection of the leucocytes; over 75% of the immunized and control fish had leucocyte‐associated viraemia from 6 to 15 wpc. When the organs were tested at 15 wpc, the immunized fish showed fewer infected organs per fish, and a lower prevalence of infection and virus titres in individual organs than the control fish, but these differences were not significant. Immunized male and female fish shed IPNV in the reproductive products, suggesting that immunization of adult fish would not prevent vertical transmission of IPNV to pr

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00336.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00337.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00338.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1995.tb00339.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY