摘要:

Abstract.A dot‐blot hybridization test has been developed for the detection of infectious pancreatic necrosis virus (IPNV) in infected fish. For this purpose, cloning of the dsRNA of the West Buxton strain of IPNV was carried out. Two cDNA clones (WB and A4) were characterized for use as diagnostic probes and corresponded to IPNV genome segments A and B. respectively. Clone WB1, with an insert of 812 base pairs, showed an 87 and 77% nuclcotidc sequence homology with the corresponding sequences of Jasper and N1 strains, respectively. Clone A4, with an insert size of 596bp, presented a nuclcotidc sequence homology of 90 and 80% with the corresponding sequences of the Jasper and Sp strains, respectively. Both probes were able to detect 15 ng of purified dsRNA, and were highly efficient in detecting the RNA of American IPNV strains. However, the A4 probe was less effective than WB1 in hybridizing to RNA from European and Spanish strains of IPNV. Both probes detected IPNV RNA in cells 4–8h post‐infection with the homologous West Buxton strain, 8–12h post‐infection with other American strains and 24h post‐infection with the European strains of IPNV. The method was less sensitive in detecting IPNV RNA directly in infected fish tissues. However, the present authors obtained a 100% effectiveness to detect viral RNA in cells inoculated with fish tissues confirmed by conventional diagnostic methods as being infected with IPNV. Therefore, the hybridization test is appropriate if combined with conventional diagnostic procedures, e.g. applying the dot blot hybridization test on tissue cultures 12–24 h after inoculation with infected fish tissu

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00341.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Extracellular hacmolytic activities ofAeromonas salmonicidassp.salmonicidato salmon red blood cells were shown to be due to different forms of the membrane‐active enzyme glyccrophospholipidrcholcstcrol acyltransferase (GCAT). About 10% of the total haemolytic activity was due to a high molecular mass complex of LPS and GCAT (mol. mass>1000kDa), containing 35–50% neutral sugars and 1.5–2.0% protein. Some haemolytic activity (30–40% of total), corresponding to 50–70kDa by gel filtration, also contained GCAT‐activity and may represent aggregated forms of GCAT. However, about 50% or more of the haemolytie activity was due to a protein of 26kDa free GCAT. Rabbit antibodies to GCAT neutralized the hacmolytic activity of both GCAT and GCAT‐LPS. A transposon‐produccd serinc protease negative mutant of the sameA. salmonicidastrain showed reduced haemolytic activity. The mutant produced a 38‐kDa GCAT proform of low hacmolytic activity. The proform was processed by autogenous scrinc protease to a highly hacmolytic 26‐kDa molecule with pl 6.3, similar to GCAT of the parent strain. The weakly haemolytic GCAT‐LPS analogue of the mutant strain did not contain detectable amounts of the 26‐kDa molecule and was not

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00342.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Young rainbow trout were fed diets containing different combinations of ascorbyl‐monophosphatc (vitamin C) and all‐rac‐alpha‐tocopheryl acetate (vitamin E) for 31 weeks. The fish fed a diet deficient in both vitamins exhibited a high mortality and were anaemic after 8–12 weeks. Histopathological examination revealed a severe muscular dystrophy and splenic haemosiderosis. Fish fed a diet deficient in vitamin C but high in vitamin E developed the typical signs of vitamin C deficiency after 16–20 weeks, including reduced growth rate, haemorrhages and gill alterations as well as severe deformations and fractures of the vertebral column. A diet deficient in vitamin E but high in vitamin C led to splenic haemosiderosis after 20 weeks. At the end of the experiment, this group showed significantly decreased haematocrit, haemoglobin content and red blood cell numbers and increased spontaneous erythrocytc haemolysis. In a second experiment, older fish of the same origin were fed diets containing high or low levels of ascorbyl‐monophosphatc and all‐rac‐alpha‐tocopheryl acetate, respectively, for 23 weeks. The results were qualitatively the same as in the first experiment, but the onset of mortality in fish fed the diet deficient in both vitamins occurred later (weeks 18–23) and deformations of the vertebral column were absent. Haematocrit, haemoglobin content and red blood cell numbers were significantly decreased in the group fed the diet deficient in both vitamins and crythrocyte haemolysis was increased in both groups receiving a vitamin E free diet, the diet deficient in both vitamins having a more pronounced effect. The results of these two experiments indicate that there is an interrelation between vitamins C and E in rainbow trout. Possible mec

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00343.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Purification andin vitrocultivation techniques were developed for the fish haemoflagellate,Trypanosoma danilewskyi.The parasites were isolated and purified from the peripheral blood of experimentally infected goldfish, using a combination of Ficolt‐paque gradient centrifugation to remove fish red blood cells andin vitroincubation to remove the remaining fish leucocytes. A serum‐free culture medium forT. danilewskyisupported both short‐ and long‐term cultivation of the haemoflagellates. The serum‐free medium is a mixture of reagents available commercially: Leibovitz's L‐15 medium, Dulbecco's Modified Eagle Medium and Hank's balanced salt solution. The doubling time was calculated to be 44.4 × 7.8h. Typically, a two‐ to five‐fold increase in the number of cultured parasites was observed on day 7 after subculture with 1 × 106and 5 × 105trypanosomes ml−1, respectively. When administered to fish, thein vitro‐derived parasites caused an infection and pathology whose characteristics were similar to those observed following infection with trypanosomes obtained from infected goldfish. The freshly isolated andin vitro‐grown parasites were successfully cryoprescrvcd in the culture medium containing 10% glycerine at −80°C for at least 3 months. Although the viability of the parasite decreased by 40–50% after thawing, cryoprcserved parasites retained the ability to infect goldfish.Correspondence: Dr M. Belosevic, Associate Professor, Department of Zoology, CW‐312 Biological Sciences Building, University of Albert

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00344.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.A disease survey was conducted in North East Sumatera, Indonesia, during June and July 1991. The objeet was to obtain information regarding the diseases present in shrimp culture faeilities. Shrimp were sampled for histopathological examination and details of the farm management and environment were recorded. The stocks sampled included some reported to be suffering from disease problems and some reported to be in good health. Samples were taken from 24 pond farms, five hatcheries and a broodstock fisherman. All farms and hatcheries culturedPenaeus monodonFabricius, one farm also culturedPenaeus merguiensisde Mann, and two culturedMetapenaeusspp. Several wild caughtP. monodonfemale broodstoek and some wild rice shrimp (Acetesspp.) were also sampled. The disease conditions detected inP. monodonwere monodon baculovirus (MBV), hepatopancreatic parvo‐likc virus (HPV), septic hcpatopancreatic necrosis (SHN), bacterial septicaemia (BS), haernocytie enteritis (HE), lymphoid organ pathology (LOP), external fouling organisms (EFO), and a single unconfirmed case of infectious hypodcrmal and haemopoietic necrosis (IHHN). TheAcetesspp. from one site had a microsporidean infection in the striated muscle of the abdomen. EFO was the most common disease condition, and was identified in 16 farms and three hatcheries. MBV was detected in 14 farms, three hatcheries and in one broodstoek. SHN was found in 13 farms with one case of concurrent BS and LOP was found in eight farms. HE was found in four farms and HPV was identified in shrimp with MBV on two farms and as the only disease in one broodstoek. The significance and implications of these findings for the developing industry in Indonesia arc discusse

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00345.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.A bath challenge system was used to infect carp.Cyprinus carpioL., withAeromonas salmonicidasubsp.nova, the causative agent of carp cruthrodermatitis. Bath‐challenged fish became infected with the bacterium exihibitinng typical signs of the disease, Carp that were sublethally bath exposed became infected and exhibited some skin lesions, but after one week, these quickly healed and the animals fully recovered from the infection, Naive fish that had not been previously exposed to the bacterium had mortalities of 100% when infected by the subcutaneous route and 40–60% by the bath route of infection. Carp that received sublethal infections were able to withstand subsequent lethal infection and recover regardless of the route of infection. Sublethally bath‐exposed carp were protected from subsequently lethal challenges of A.salmonicidasubsp.novafor at least 5 m

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00346.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Studies were conducted to clarify the relationship between growth rate and disease progression of erythrocytic inclusion body syndrome (EIBS) in artificially infected coho salmon,Oncorhynchus kisutch(Walbaum). In the diseased state, the haematocrit values decreased and the number of erythrocytes with inclusions was higher in faster growing fish. Rapid growth was accompanied by an abundance of immature erythrocytes, which had the greatest incidence of inclusion bodies.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00347.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.A panel of 11 monoclonal antibodies (MAbs) was used in an immunodot assay to investigate the antigenic relationship of a representative selection of aquatic biroaviruses isolated in Norway from different species of both carrier and diseased fish. All the 81 isolates shared a serogroup A‐speeifie epitopc, and 67 of them had a reaction pattern identical to the Sp‐type strain. Of the other 14 isolates, nine resembled the Sp‐type strain, two resembled both the Sp‐ and He‐type strains, two were closest to the Ab‐type strain and one resembled the Te‐type strain. Sp‐related strains were predominant from all nine host groups, including from both Atlanticsalmon, Salmo salarL., with infectious pancreatic necrosis (IPN) and healthy. Atlantic salmon. The N1 strain reacted identically to the

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00348.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00349.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1994.tb00350.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY