Myxosoma cerebralis: Comparative Sensitivity of Spore Detection Methods

1974 ◽  
Vol 31 (10) ◽  
pp. 1597-1600 ◽  
Author(s):  
Maria E. Markiw ◽  
Ken Wolf

Physical and biophysical methods of detecting spores of Myxosoma cerebralis were used in sequence on 87 individual fingerling rainbow trout (Salmo gairdneri) from two populations with a low incidence of infection. Physical methods of releasing spores from the organs of equilibrium, gill arches, or the axial skeleton gave an estimated rate of infection of 2.3–4.6%. Each succeeding step — pepsin digestion, trypsin digestion, and differential centrifugation through 55% dextrose solution — revealed additional infected fish. The final step of the sequence detected 10.5 times more infected fish than were found by examination of the organs of equilibrium or the axial skeleton with physical means; the true incidence was at least 24.1%. Procedures are described for using biophysical methods on 60-fish pools for hatchery inspection work and also on the more bony skeletons of mature fish.

1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.


1980 ◽  
Vol 37 (4) ◽  
pp. 746-750 ◽  
Author(s):  
C. Michel

With the aid of published information, we have developed a standardized and reproducible experimental model of furunculosis in rainbow trout (Salmo gairdneri). The infective doses (LD50 = 200 to 2000 germs, i.m.) employed strains of Aeromonas salmonicida, the virulence of which was maintained by passage in 15-g fingerlings. The number of viable cells in the dose was conveniently determined using the drop-plate enumeration technique; however, meaningful cell counts could only be obtained if broth cultures used for infecting the fish were harvested early in the exponential growth phase (OD < 1.000 at 525 nm). Better results were obtained with intramuscular injection than with intraperitoneal injection. The infection procedure involved injecting a dose of 10 LD50, intramuscularly, into each of 30 fish held at 15 °C and recording the mortalities for 10 d. Protection tests in which Tribrissen (28 mg sulfadiazine and 5.6 mg trimethoprim/kg fish for 8 d) was fed or tetracycline (1 mg per fish) i.m. injected into the infected fish served to demonstrate the value of the model. Results were in agreement with field observations with no death for treated fish and a mortality of 96%, for untreated fish. Key wordss rainbow trout, Salmo gairdneri; Aeromonas salmonicida, furunculosis, experimental infection


2016 ◽  
Vol 116 (07) ◽  
pp. 146-154 ◽  
Author(s):  
José Navarro-Fernández ◽  
María Morena-Barrio ◽  
José Padilla ◽  
Antonia Miñano ◽  
Nataliya Bohdan ◽  
...  

SummaryThe key haemostatic role of antithrombin and the risk of thrombosis associated with its deficiency support that the low incidence of antithrombin deficiency among patients with thrombosis might be explained by underestimation of this disorder. It was our aim to identify mutations in SERPINC1 causing transient antithrombin deficiency. SERPINC1 was sequenced in 214 cases with a positive test for antithrombin deficiency, including 67 with no deficiency in the sample delivered to our laboratory. The p.Val30Glu mutation (Antithrombin Dublin) was identified in five out of these 67 cases, as well as in three out of 127 cases with other SERPINC1 mutations. Genotyping in 1593 patients with venous thrombosis and 2592 controls from two populations, revealed a low prevalent polymorphism (0.3 %) that moderately increased the risk of venous thrombosis (OR: 2.9; 95 % CI: 1.07–8.09; p= 0.03) and identified one homozygous patient with an early thrombotic event. Carriers had normal anti-FXa activity, and plasma antithrombin was not sensitive to heat stress or proteolytic cleavage. Analysis of one sample with transient deficit revealed a type I deficiency, without aberrant or increased latent forms. The recombinant variant, which lacked the two amino-terminal residues, had reduced secretion from HEK-EBNA cells, formed hyperstable disulphidelinked polymers, and had negligible activity. In conclusion, p.Val30Glu by affecting the cleavage of antithrombin’s signal peptide, results in a mature protein lacking the N-terminal dipeptide with no functional consequences in normal conditions, but that increases the sensitivity to be folded intracellularly into polymers, facilitating transient antithrombin deficiency and the subsequent risk of thrombosis.


1993 ◽  
Vol 56 (8) ◽  
pp. 725-729 ◽  
Author(s):  
ROBERT L. BUCHANAN ◽  
CATHERINE M. DEROEVER

Scientific information pertaining to the incidence of foodborne disease and the sources of pathogenic microorganisms is often limited in relation to the knowledge needed to make informed microbiological food safety decisions. Inherent limitations in the current epidemiological reporting system constrain its usefulness for ascertaining the true incidence of foodborne disease. Additionally, current detection methods are insufficient to make real-time decisions on the microbiological safety of products. An integrated approach that combines enhanced epidemiological data, improved detection methods, detailed knowledge of the behavior of pathogens in food systems, and development of techniques for making quantitative risk assessments is essential for the development of a comprehensive, cost-effective strategy for assuring microbiologically safe foods.


1982 ◽  
Vol 39 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
A. Silim ◽  
M. A. S. Y. Elazhary ◽  
A. Lagacé

We investigated the susceptibility of trouts of different species and origins to infectious pancreatic necrosis virus (IPNV) and the pathogenicity of three strains of IPNV for brook trout (Salvelinus fontinalis) of various origins and lake trout (Salvelinus namaycush) of a single origin. Fish were inoculated by immersion in water containing 105 PFU of virus/mL for 6 h. Susceptibility to IPNV infection was assessed by counting dead fish over a period of 21 d after infection and on histological lesions in the pancreas, kidney, and intestine of the infected fish. Different species of trouts had different susceptibility to IPNV strain 3865. Brook trout had the highest mortality followed by rainbow trout (Salmo gairdneri), whereas the least mortality occurred in lake trout. Brook trout from Crowford, Nebraska, were more than twice as susceptible as the same species from Baldwin Mills, Quebec. Rainbow trout also varied in susceptibility as a result of origin. Virus isolate 3B, originally isolated from chain pickerel (Esox niger), was less virulent than isolates 4495 or 3865 (both from trout). Hatcheries that use water from sources containing pickerel may increase their chances of IPN infection.Key words: trout species, infectious pancreatic necrosis virus, resistance


1973 ◽  
Vol 30 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
P. McCart ◽  
P. Craig

Two isolated populations of Arctic char (Salvelinus alpinus) in spring-fed tributaries of the Canning River, Alaska, had meristic characters that corresponded to those of the Western Arctic–Bering Sea form of Arctic char. The two populations demonstrated slight differences in growth rates, age at maturity, longevity, and food habits. The fish were characterized by small size (maximum 235 mm), low growth rates, low fecundities (maximum 199 eggs), and annual spawning after maturity. Mature fish were darkly pigmented and parr marks were retained throughout life. The spawning season appeared to be sometime in November, when the eggs of mature females averaged 3.8 mm in diameter.


1967 ◽  
Vol 41 (1) ◽  
pp. 71-88 ◽  
Author(s):  
John W. Smith ◽  
H.Harford Williams

Of the 1,090 hake, Merluccius merluccius (L.), examined for Aporocotyh spinosicanalis, 323 were infected. Only adult flukes were found and these in the heart and bulbus arteriosus only; this habitat specificity and the apparent strict specificity of the fluke to hake are briefly discussed. The occurrence of from 1 to 5 flukes in each infected fish was common but up to as many as 60 were recorded. The incidence of infection is high in hake from shallow water in some areas to the west of Scotland; a particularly high incidence was found in the Minches and Sea of the Hebrides area. The incidence of infection was very low to the southwest of the British Isles and off Hartlepool in the North Sea; only 1 of 82 fish from these regions was infected. The possible use of A. spinosicanalis as a biological tag is discussed. A significant difference was found in the incidence of infection in hake of different length groups, the most heavily infected being those measuring 26 to 55.9cm.; small hake (25.9 cm. and below in length) from shallow water showed a low incidence of infection. Speculations are made on the possible course of the life-cycle of A. spinosicanalis. There was no significant difference in the distribution of the fluke in male and female fish and no obvious effect on the condition of the host was observed.


1987 ◽  
Author(s):  
Ph de Moerloose ◽  
G Reber ◽  
Ph Minazio ◽  
C A Bouvier

A 43-year old man presented a pulmonary embolism. Despite a negative family history for thromboembolic disorders, the unusual circumstances of apparition and the relatively young age of the patient prompted us to study carefully the coagulation parameters. Routine coagulation tests, as well as plasminogen, alpha-2-anti-plasmin, protein C and protein S were all within normal range. Biological and immunological assays of AT III were performed on 12 members of the family and showed a low AT III activity in the propositus and other members of this family (mean 50%), but normal immunologic levels. Crossed immunoelectrophoresis in absence of heparin showed a normal pattern, but in presence of heparin showed an abnormal peak as compared with controls. Kinetics experiments showed a normal inhibition of Xa and 11a in absence of heparin, but abnormal in presence of heparin. An affinity chromatography on heparin Sepharose revealed two populations of AT III, one of which was devoid of heparin cofactor activity.The toponym AT III Geneva is proposed for this new familial abnormal AT III with defective heparin cofactor activity. This family confirms the low incidence of thromboembolic events reported in this type of AT III variant.


1975 ◽  
Vol 32 (9) ◽  
pp. 1648-1652 ◽  
Author(s):  
A. J. Ross ◽  
W. T. Yasutake ◽  
Steve Leek

Phoma herbarum, a fungal plant saprophyte, was isolated from diseased hatchery-reared coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), and rainbow trout (Salmo gairdneri). The disease was observed at 10 national fish hatcheries in Washington and Oregon, but the low incidence of experimental infections indicate that it is only weakly contagious. Histopathological examination suggests that the air bladder is one of the primary organs infected. The visceral organs are also affected in both natural and experimental infections.


1985 ◽  
Vol 63 (12) ◽  
pp. 2778-2779 ◽  
Author(s):  
G. F. Wagner ◽  
M. Hampong ◽  
D. H. Copp

The rate of in vivo 45Ca uptake was monitored twice weekly over a period of 9 weeks in two different populations of rainbow trout fry. The rate of uptake cycled approximately every 11 days and the two populations appeared to be in synchrony regarding this cycle. The results are discussed in relation to the cyclical pattern of growth exhibited by salmonids.


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