摘要:

AbstractSea bass head kidney cells were incubated at several temperatures with or without opsonized zymosan, Luminol was added to amplify light emission. When stimulated by zymosan cells emitted higher chemiluminescence (CL) at low temperatures (5–20°C) than at high temperatures (25–40°C). CL reached its peak earlier at high temperatures than at low temperatures. Unstimulated cells showed a low level CL response which rose with increasing temperature. Sodium azide inhibited CL b

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01223.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe use of a discontinuous density Percoll gradient in the separation of channel catfish peripheral blood leucocytes is described. The procedure yielded fractions enriched in monocytes and lymphocytes at the 1·060–1·065 g/ml interface, lymphocytes at the 1·065–1·070 g/ml interface, and neutrophils at the 1·070–1·080 g/ml interface. Cell purities among fractions ranged from 14·4–51·6% for monocytes, 61·4–72·8% for lymphocytes, and 60·4–79·2% for neutrophils. Factors influencing the outcome of the separation procedure include the use of pooled blood samples and calcium‐ magn

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01224.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA disease of saltwater, cage‐cultured tilapia,Oreochromis mossambicus(Trewavas), caused by the marine monogenean,Neobenedenia melleni(MacCallum, 1927) Yamaguti, 1963, is described. Up to 400 parasites were found attached to the body surface of individual fish. Heavily infected fish showed hyperirritability, heavy mucus secretion and discoloration. Pathology was most marked on the eye, with corneal opacity initially, followed by buphthalmos, corneal ulceration and rupture of the eye with subsequent degeneration of internal structure. The infection was successfully treated using 2 min freshwater dip

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01225.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe microsporidian parasite Thelohania sp. was present in a population of Cherax quadriearinatus in the Mitchell River, north Queensland. An infection rate of 7‐‐8% was recorded for the population sampled. Cohabitation, passage of spores through fish, ingestion of spores and injection of blood from an infected individual failed to elicit infection in laboratory held animals. Injection of spores elicited a host responseconsisting of encapsulation and melanization of spores. Further studies are necessary to clarify the taxonomic position and mode of transmission of this paras

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01226.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe role of A‐layer (A), protease (P) and haemolysin (H) as virulence factors of Aeromonas salmonicida, the aetiological agent of fish furunculosis, was a investigated using three strains of the bacterium. Strain MT004 lacked the A‐Iayer (A−) and produced extracellular caseinase and gelatinase (P+) and haemolysin (T‐lysin; H+). Strain MT028 was A−, P−and H−, and strain MT048 was A+, P+and H−. The pathology and LD50 produced in rainbow trout by cells or extracellular products (ECP) of each strain were determined. The ECP was produced by two different methods where the protease and haemolytic activities differed in relative levels, or when the protease of MT004 ECP was inhibited by the serine protease inhibitor PMSF. The results indicate that the presence of A‐layer is not essential, at least for a moderate degree of virulence; that in vitro production of extracellular proteases is not a requisite of virulent strains; that presence of protease and haemolysin in ECP can be correlated with the development of certain lesions and a rapid time to death but cannot be correlated with the lethal toxicity of the ECP. The authors conclude that an as‐yet unrecognized component of ECP is responsib

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01227.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn this second study of the myxozoan Zschokkella russelli Tripathi from Wales, infection occurred in 71‐0% of five‐bearded rocklings, Ciliata mustela L.; all infected fish were mature and immature fish were uninfected. Histologieal studies showed ehanges to gallbladder and liver that mostly conformed with earher findings, but sinusoidal dilation, which had not been seen previously, was present in three of 22 infected livers. Thickening around hepatic ducts was shown by transmission electron microscopy (TEM) to comprise fibroblasts and associated collagen bundles, while the attenuated epithelium of hepatic ducts bore few mierovilli. Zschokkella russelli plasmodia were seen by TEM to have fine tubular structures, particularly adjacent to developing sporonts. Spores showed long extensions to the sporoplasm, while spore valves had up to 18 surface ridges each and depressions between ridges were supported by microtubules. Otherwise, in its general ultrastructure and sporogenesis Z. russelli resembled other myxospor

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01228.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe development and applicability of a dose‐controlled experimental infection with atypicalAeromonas salmonicidain carp is described. The proliferation and clinical manifestations of experimentally induced carp erythrodermatitis mimicked a natural infection. Anin‐vivoassay was used to evaluate the lethal properties of cell‐free culture supernatants and a simple serum‐free growth medium was devised for maintaining the virulence of the challenge strain. Depending on the inoculation dose, a sublethal (chronic) to a lethal (acute) infection could be induced, and a dose‐response relation was observed betweenA. salmonicidainoculum size and carp mortality. The dose‐controlled experimental infection was used as a challenge test for laboratory evaluation of the efficacy of potential vaccine candidates. The vaccine candidates tested, a cell envelope preparation, purified lipopolysaccharide and purified A‐layer (ACE) protein showed no protection or only a feeble one at the best, while formalinized whole cells showed a consistent but only moderate protection. In contrast, when concentrated, detoxified culture supernatant was used, the carp were protected against a subsequent lethal challenge. These observations indicate that immunity againstA. salmonicidaextracellular products is of pri

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01229.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractTwo groups of European catfish,Silurus glanisL., fingerlings were infected with channel catfish virus (CCV) by either intraperitoneal injection with 105TCID50of CCV, or bathing in water containing 105TCID50of CCV per 1·0 ml. The virus was isolated from spleen, intestine and brain of CCV‐injected fish at day 1 and the titres ranged from 102·1to 103·3TCID50/g. However, the tissue distribution of CCV was irregular and no virus was isolated after day 3 post‐exposure. In CCV‐bathed fish, the virus was isolated only from the liver of one specimen at day 3 post‐exposure. No clinical signs of CCV disease developed in any of the fish. Specimens in each regime from all sampling periods showed some minor histopathological changes, but there were no differences between treatments. Lesions included oedema and focal haemorrhage in the liver and the spleen was congested. Electron micrographs of tissue samples showed the presence of a few virus particles around the nuclei of kidney, spleen and intestinal cells, and in or around a myelinated nerve within the optic lobes of infected fish during the first 4 days of

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01230.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01231.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb01232.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY