摘要:

Abstract.An outbreak of clinical furunculosis in commercially reared Atlantic salmon,Salmo salarL., broodfish in fresh water was successfully treated with a single intraperitoneal injection of oxytetracycline. The mean serum oxytetracycline residue in these fully mature fish did not decline and, at 8 weeks post‐injection, was 3·7 μg/ml. In contrast, the mean serum residues in other fully mature but healthy fish declined during an 8‐week experimental period to 1·3 μg/ml. The mean concentration of oxytetracycline in the liver of healthy mature fish was approximately two‐fold that of similar aged but non‐mature fish, and approximately four‐fold the concentration found in post‐smolts. Oxytetracycline residues 8 weeks after injection exceeded the minimum inhibitory concentration required for oxytetracycline sensitiveAeromonas salmonicidaisolates in all groups, therefore under these circumstances, this antibiotic may be effective at a lower dose than that currently recommended. The histology of the liver from the furunculosis‐surviving broodfish showed an increase in tissue lesions when compared with the other mature and non‐mature fish in fresh water. The combination of prior infection and the physiological status of fasting broodfish may have influenced the rate at which this antibiotic is removed, and, in cases where these residues persist, there may be further

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00279.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.The use of an indirect enzyme‐linked immunosorbent assay (elisa) for the detection of channel catfish antibody toEdwardsiella ictaluriis described. Changes in agglutination titre in fish immunized withEdwardsiella ictaluriheat killed whole bacterins or lipopolysaccharides were reflected by corresponding changes inelisareadings. Relatively high correlations were observed amongelisaOD readings, computedelisatitres and corresponding agglutination titre

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00280.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.The antibacterial effect of two lysozyme variants purified from rainbow trout,Salmo gairdneriRichardson, kidney was investigated as part of a project directed towards increasing the disease resistance of fish by the transgenic technique. Seven bacterial strains from five Gram‐negative species, of which one was considered non‐pathogenic, were examined. One of the rainbow trout lysozymes was surprisingly potent, having substantial antibacterial activity on all strains tested. Hen egg‐white lysozyme was bactericidal only against the one species considered non‐pathogenic. The data suggest that lysozyme does play a role in the disease defence of rainbow trout and that the gene for the most active lysozyme may be suitable for testing the transgenic s

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00281.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.The livers of Atlantic tomcod,Microgadus tomcod(Walbaum), from the Hudson and Pawcatuck Rivers were evaluated histologically and described using paraffin and plastic sections. Fatty infiltration, basophilic foci, areas of cellular alteration and hepatocellular carcinoma were widespread in Hudson River samples. In fact, no truly normal tissues were found. Pawcatuck samples had variable levels of lipid and a low prevalence of other alterations. Evaluation of the histological evidence suggests that hepatocellular carcinoma in Hudson River tomcod results from multiple DNA lesions and that areas of cellular alteration give rise to the larger, more invasive form of hepatocellular carcinoma. Glutaraldehyde and OsO4fixed livers were used to determine differences in cell types and lipid levels. Pawcatuck samples possessed hepatocytes and dark cells forming the parenchymal tissue, whereas Hudson samples lacked dark cells. Hepatic lipid levels were significantly higher in Hudson River fish than in Pawcatuck fish, 36·3 and 11·0% respectively. The elevated hepatic lipid levels in Hudson River tomcod may represent a metabolic response to detoxificatio

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00282.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.Sensitized lymphocytes isolated from the immunized eel,Anguilla japonica, upon interaction with the antigensin vitro, elaborated into the medium a soluble factor which was capable of inhibiting the migration of peritoneal exudate cells harvested from guinea pigs. Production of migration inhibition factor (MIF) was greatest to the specific antigen although there was also some nonspecific release. The elaboration of MIF from the sensitized lymphocytes occurred from the third day after immunization of eels and was detectable until day 106. The inhibitory activity from the blood appeared to persist over a longer period compared to that from the spleen and the anterior kidney. The inhibitory activity, however, was diminished by starvation of the immunized eels.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00283.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.Diseases of bivalve molluscs characterized by the presence of prokaryotic intra‐cytoplasmic inclusion bodies in epithelial cells are reviewed. The paper reports the history, clinical and pathological findings during hatchery epizootics of chlamydiosis in larval and postmetamorphic bay scallops,Argopecten irradians(Lamarck), and enzootic infection in wild, captive and cultured adult and juvenile bay scallops during a 15‐year period (1972–1987) of surveillance for scallop diseases in the northeastern Atlantic coastal region of the United States. The disease was found in 44·4% of adult bay scallop laboratory accessions as an endemic disease without overt clinical signs or mortalities, and as a highly fatal epizootic disease with a rapid course in 20% of hatchery‐reared larval and postmetamorphic bay scallop accessions. The pathogenesis and development of the chlamydial agent during hatchery epizootics are described. The importance of the congenital ‘childhood’ diseases of larval bay scallops and other species of bivalve molluscs

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00284.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.Serologic relatedness of the two life stages of the salmonid whirling disease parasiteMyxosoma cerebralisHofer, 1903 — myxosporean spores from fish cartilage and actinosporean triactinomyxon spores from aquatic tubificids — were investigated. When the direct fluorescent antibody technique was used, anti‐triactinomyxon and anti‐M. cerebralisrabbit sera conjugated with fluorescein isothiocyanate cross‐reacted with the respective heterologous life stage. Both stages showed similar locations of specific fluorescence with conjugates of either homologous or heterologous serum. Thus, serology supports the relatedness of the myxosporeanM. cerebralisand the actinosporean triactinomyx

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00285.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.The tilapine fish species belonging to the genusOreochromisbrood developing eggs and early fry in their buccal cavities. Though it is obvious that mouth brooding facilitates a physical protection from environmental hazards by keeping fry in this confined environment, it is still not clear whether mouth brooding provides any other type of protection to the early fry against pathogens. Investigations were made to study the possibility of protection of early fry ofO. mossambicusagainst infections of the ciliate parasiteIchthyophthirius multifiliisduring mouth brooding. Adult females were effectively immunized againstI. multifiliis.Brooding immune females were then challenged with controlled infections ofI. multifiliistomites and the survival of the fry compared to those of challenged non‐immune brooding females. The study demonstrated that there was some protection from the infection conferred to fry during mouthbroodin

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00286.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.Guidelines for the preparation of a species description of myxosporean species are proposed. The establishment of a new myxosporean species has to be based on the morphology of both spores and vegetative stages as observed in a fresh state. All important diagnostic features are listed and diagrams for size measurements are presented.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00287.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract.Sporadic cases of a systemic protozoal infection with cells resemblingDermocystidiumsp. are described from cultured rainbow trout,Salmo gairdneriRichardson, from France and brown trout,Salmo truttaL., and Atlantic salmon,Salmo salarL., from Ireland. Classical proliferative kidney disease was additionally found in the rainbow trout and PKX‐like cells were also seen in the brown trout and salmo

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1989.tb00288.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY