摘要:

Abstract.The specificity and kinetics of the immune response of rainbow trout (Salmo gairdneri) to single injections of an O‐antigen extracted from the bacterial pathogenYersinia ruckeri, which causes enteric redmouth in fish, were investigated by the passive haemolytic plaque assay and serum antibody quantitation. Doses ranging from 5 ng to 500 mg in 10‐fold increments were injected intraperitoneally into groups of trout held at 17 × 1°5°C. The occurrence of plaque forming cells (PFC) and humoral antibody was followed for 35 days after injection. Trout gave an immune response to doses of 500 ng and above. Seven days after injection no humoral antibody was detected, but PFC were found in the spleen. The maximum PFC numbers occurred 11 days after injection. On day 21, few PFC were found, whereas serum antibody titres were highest. The antibody from immunized trout showed little or no cross‐reactions with sheep red blood cells passively labelled With antigens from other fish p

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00156.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.The prevalence of a chlamydial infection in hatchery‐reared adult hard clamsMercenaria mercenaria(L.) from Great South Bay, Long Island, New York was relatively high and seasonally stable. Infection occurred early in life while juvenile clams were still within the hatchery. Fluorescent antibody tests suggested that the clam agent shares the group antigen specific for chlamydia, but to a lesser degree than a known chlamydial strain used as a positive control. The method of Gimenez failed to stain elementary bodies in clam cell inclusion bodies. Based on the observations of this study, the inclusion body agent in the hard clam differs from known strains of chlamydia. Characterization of the clam chlamydia must await the successful propagation of the agen

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00157.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Anin vitrotechnique was developed to screen drugs for toxicity to laboratory cultured protozoans. Drugs were diluted using standard microtitration equipment. An easily cultured protozoan,Tetrahymena pyriformis, was added to the dilutions of drugs and viability was checked daily for 10 days. Drugs used as a model system to test the technique were formalin and malachite green. Effective concentrations of formalin determined by thisin vitrotechnique were close to recommended therapeutic treatment levels forIchthyophthirius. Malachite green was effective at concentrations in excess of recommended therapeutic treatment levels forIchthyophthirius. The synergistic effect of formalin and malachite green was demonstrated. This technique can he of use in determining effectiveness of new drugs as parasiticides.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00158.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Fungal infection of both wild and hatchery‐reared sexually mature brown trout,Salmo truttaL., was caused bySaprolegnia diclinaHumphrey Type 1. The major ions in the serum of infected fish were all significantly reduced in concentration and it is suggested that the primary cause of death was osmoregulatory breakdown resulting in a lethal haemodilution. Severe hypoproteinaemia and a significant reduction in the albumin/globulin ratio were reflected in the electro‐phoretogram of the serum proteins from infected f

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00159.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.Lymphocystis disease is reported from seven fish species in 48 of Wisconsin's 72 counties (67%). It was previously known from only two fish species in five counties. The record from northern pike,Esox IndusL. is new. Five other host records are new for Wisconsin. A relationship between the disease distribution in new waters and walleye,Stizostedion vitreum(Mitchill), stocking sources is noted. Histologlcal observations from black crappie,Pomoxis nigromaculatus(Lesueur) and walleye are similar to previously published accounts. Events in hyaline capsule degeneration are described for the first time. In Wisconsin, the disease was most commonly observed in the spring, particularly in walleye, but was consistently evident throughout the rest of the year.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00160.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.The epidemiology of PKD is described as it relates to one affected farm in Northern Ireland. From 1972–1976 stocking and management practices led to mortality of 10–15% amongst the 0+fish. 1+or older fish were never affected. In 1977 and 1978, however, delaying the stocking of the farm until July eliminated deaths in the 0+fish, and mortality in these 1977‐moved fish the subsequent year remained at an absolute minimum. Preliminary observations suggest that a means of controlling the disease has been found.Experimental work demonstrates that the resistance of 1 +or older fish is due to previous exposure and is not an age‐related immunity. Experimental work also suggests the presence of an incubation period of 6–7 weeks and that the peak time of infectivity is probably around May. None of the evidence detracts from the possibility that an infectious agent is involved although an attempt to transmit the disea

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00161.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.An unidentified mycoplasma was isolated from cultures of Atlantic salmon (AS) cells and implicated as the cause of cytopathic effects (CPE). The agent did not visibly affect RTG‐2 cells. Experimental infection of RTG‐2 cells withAcholeplasma laidlawiiresulted in increased cellular granularity and destruction. Scanning electron microscopic (SEM) examination of infected RTG‐2 and AS cultures revealed typical mycoplasmas distributed on cell surfaces and a marked effect on the cell surface topography, characterized by a loss of microvilli and cellular processes. SEM also revealed mycoplasmal contamination that was not detected by culturing. Comparisons of contaminated and uncontaminated RTG‐2 cells showed enhanced (2–100 fold) replication of infectious pancreatic necrosis virus (IPNV) and infectious haematopoietic necrosis virus (IHNV) in the presence of A,

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00162.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.The structure of the parasite‐host interface at the site of attachment was studied forGlaridacris catostomi, G. larueiandHunterella nodulosa, caryophyllid tapeworms of the white suckerCatostomus commersoni. Light microscope observation of fish infected withH. nodulosashowed a loss of intestinal epithelium and lamina propria, and a chronic inflammatory response characterized by infiltration of lymphocytes and extensive hyperplasia of the submucosal tissue; intestinal pathology associated withG. catostomiandG. larueiwas minimal. Electron microscope examination of the parasite‐host interface revealed that in no case does parasite tissue come into direct contact with host tissue.H. nodulosais separated from host tissue by an amorphous layer of electron lucent material (the ‘eosinophilic matrix’ seen with the light microscope) which appears to act as an adhesive; this material is a secretory product of the scolex glands. InG. catostomiandG. larueia layer of material separating parasite from host tissue was also found, but it is not clear whether this layer is adhesive or pro

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00163.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00164.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1979.tb00165.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY