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Geology topics

S. F. Snieszko

Publications and source records attributed to S. F. Snieszko.

At least 109 records · Page 6Linked to original sources

A more comprehensive description of Bacterium salmonicida

The purpose of this study was to establish a set of descriptive data which could be used as a reference or a standard in the identification of Bacterium salmonicida, the cause of furunculosis in fish. Since a complete description of B. salmonicida was not available, bacteriologists were not in a position to identify this microorganism in a manner which would meet the rigorous requirements of present‐day bacteriology. Ten strains of B. salmonicida were employed in these studies. A detailed description is presented which includes the morphological, cultural, and physiological characteristics of B. salmonicida. In addition, various factors such as oxygen, pH, temperature, and composition of media are discussed in terms of their influence on the formation of the melanin‐like pigment which is characteristically produced by this microorganism.

Transactions of the American Fisheries Society

Therapy of bacterial fish diseases

During the past decade considerable progress has been made in the therapy of bacterial fish diseases. This progress was possible largely because of the introduction of powerful chemotherapeutic agents such as sulfonamides and antibiotics. Fish furunculosis can be treated with very good results with sulfamerazine, sulfamethazine, and sulfaguanidine as well as by chloramphenicol and terramycin. Ulcer disease caused by Hemophilus piscium resists treatment with sulfonamides but responds well to the above mentioned antibiotics. Chemotherapy of fish diseases caused by pseudomonads is possible with chloramphenicol, but sanitary measures are preferred. External disinfections with Roccal and pyridylmercuric acetate (PMA) are satisfactory in treatment and prophylaxis of gill diseases which are probably caused by superficial infections with myxobacteria. Sulfonamides are helpful in systemic infections with myxobacteria and are also being used with some success for the control of a recently described kidney disease of salmonold fishes. Also described are methods of control of other fish diseases and of immunity in cold‐blooded animals and fishes. Most of the drugs in the described treatments may be toxic to fishes, and therefore should be used with caution.

Transactions of the American Fisheries Society

Further studies on factors determining tissue levels of sulfamerazine in trout

There is considerable variation in the tissue level of sulfamerazine among individual trout in a treated population. This fact may be the reason why prolonged sulfonamide therapy sometimes fails to free all trout from Bacterium salmonicida. The quantity of food given with a standard dosage of sulfamerazine has a pronounced effect on the tissue concentration of sulfamerazine; the concentration increased when the quantity of food decreased. It appears therefore, that trout should be fed at a rate very closely adjusted to their optimum feeding requirements for the best practical results. The start of treatment with high initial doses of sulfamerazine had no effect on the tissue concentration sustained by the maintenance dosage. The relative distribution of sulfamerazine in various organs and tissues of rainbow trout was about the same as in brown and brook trout. The only difference noticed was the lack of peak levels of short duration between the 8 and 10 days of treatment, which is characteristic for brook and brown trout.

Transactions of the American Fisheries Society

Tissue levels of various sulfonamides in trout

Studies were made on the tissue levels of sulfonamides in trout. The tissue concentrations of sulfamerazine were determined in brook trout given various doses of this drug. It has been found also that there exists a relationship between the rate of feeding, depending on the size of trout, and the tissue concentration of sulfamerazine. The level of sulfamerazine rose much faster and higher in blood and liver than in kidney and muscle. However, after the treatment was discontinued sulfamerazine level in all tissues dropped within 3 days to about 1 milligram percent. From the tested sulfonamides, sulfanilamide was absorbed fastest and produced highest tissue concentration. Sulfamerazine and sulfamethazine gave similar tissue levels, but the tissue concentration rose faster with sulfamerazine. Sulfadiazine and sulfaguanidine reached lower tissue levels. The tissue level of sulfathiazole was less than 1 milligram percent and sulfathalidine and sulfaquinoxaline were not absorbed from the intestine at all.

Transactions of the American Fisheries Society