[Increasing the effectiveness of the method of Staphylococcus phage-typing].

Eight nutrient media used for St. aureus phage-typing were assessed in parallel experiments. 22 test strains of St.

[Simulation of the Baird-Parker media formula based on Soviet ingredients for the isolation of Staphylococcus aureus].

A medium has been prepared based on Soviet nutrient agar and reagents supplemented by ingredients from Baird-Parker's medium. Its growth and selective properties are close to those of Baird-Parker's medium. The new selective medium has been recommended for isolation of S.

[Use of the agar drop method for the quantitative calculation of mesophilic aerobic and facultatively anaerobic microorganisms and coliform bacteria in food products].

The tests in agar dishes and agar drops were used simultaneously to determine the amount of mesophilic aerobic and facultative-anaerobic microorganisms and coliform bacteria in certain food products. The results of the analysis of more than 40 samples of different food products in both the tests have proved to be identical. The method can be recommended for practical use at laboratories of sanitary-epidemiological stations during prophylactic sanitary control, and at laboratories of food manufacturing enterprises.

[Experimental basis of principles for creating microbiologic standards for food products for children during the 1st year of life].

Standard media were designed simulating the gastro-intestinal contents of infants during the first year of life. These media were used in the in vitro tests to study the viability of a number of potentially-pathogenic microorganisms. It was shown that S.

[Effect of various factors on staphylococcal multiplication during the production of curd].

The paper is concerned with modeling of contamination of cheese granules with staphylococci in different stages of granule preparation under laboratory conditions. It has been shown that especially hazardous is the raw material contamination in the stages of fermentation and crushing of the curd before heating.

[Change in the sensitivity of staphylococci to phages and the possible methodological procedures in their phage typing].

In a number of pathogenic staphylococci present in a food product that has been subjected to a mild heat treatment changes in the phage pattern were studied. The heat was found to produce in a number of staphylococcal strains a change in the sensitivity to phages, as a result of which phage patterns may assume different forms without losing their pathogenic and enterotoxic properties. This may lead to an erroneous interpretation of the results subsequent to an epidemiological study of staphylococcal intoxications.

[Multiplication of staphylococci and formation of type A enterotoxin in boiled macaroni products].

Interconnection between the number of pathogenic staphylococci and the presence of enterotoxin in cooked macaroni products was studied. Precipitation in gel with antienterotoxic serum of the A type demonstrated the formation of the type A enterotoxin to be observed when 1 g of the product contained millions of the staphylococcal cells. The time period necessary for the formation of enterotoxin depended upon the initial dose of the staphylococcal contamination of the product and the incubation temperature.

[Results of typing staphylococci isolated from cows and their milk products using the basic set of phages and local phages].

The basic set of phages recommended for typing staphylococci from cattle and also of local phages were approbated. Staphylococci cultures (950 in all) isolated in various regions of the Soviet Union from milk, milk produce and from cows suffering from mastitis were studied. Percentage of cultures typed by the phages of the basic set proved to be 78.