Bacteriological examination of unbottled soft drinks. Appl. Microbiol. 10:311-320. 1962. A study of 300 samples, representing 14 different unbottled drinks, indicated that there are three vitally important criteria pertaining to their bacteriological examination. First, the total viable counts may be better accomplished by the pour-plate method, using enriched media, with incubation at either 30 or 37 C. Second, a comparative study of the coliaerogenes group and the enterococci as indices of pollution unquestionably favors the latter as the reliable indicator, owing to false interpretations of the presumptive test and to lack of accurate definition of fecal and nonfecal coliforms recovered from positive cases. The use of enterococci, however, did not provide as reliable an indicator as the pour-plate method. Third, the results with enterococci, in defining the probable source of pollution, are more precise. Experiments judiciously selected and simultaneously conducted revealed that the heat and heat-tellurite resistance tests, and the tetrazolium-reduction test, matched in relating 98.9 % of available enterococci to an animal source. Negligible but vital discrepancies were obtained with the two odd strains which qualified as human-derived according to the heat and heat-tellurite resistance tests. The differential criterion of Skadhauge and Barnes, based on the failure of animal-derived enterococci to grow in the presence of a low concentration of potassium tellurite, did not apply to the other two methods, since 99.5 %o of the recovered strains were found tolerant to the specified tellurite concentration. At the present time, the processing of Egyptian unbottled drinks is not controlled by designated standards or adequate specifications. Formulae employed in the making up of such drinks are quite varied and rest mainly on the so-called "individual art." Bacterial contamination reaching these feeds may be derived from the raw materials (usually of plant origin), water, sugar, ice, flavoring matter, coloring matter, utensils, hands of the producer, and surroundings (e.g., tables, flies, and dust). The main object of any bacteriological standards proposed for such foods is to secure three basic criteria, namely, their freedom from pathogens, toxinogenic bacteria, and high bacterial counts. Because the chief source of enteric pathogens of man is human fecal matter,
A study of 300 samples, representing 14 different unbottled drinks, indicated that there are three vitally important criteria pertaining to their bacteriological examination. First, the total viable counts may be better accomplished by the pour-plate method, using enriched media, with incubation at either 30 or 37 C. Second, a comparative study of the coliaerogenes group and the enterococci as indices of pollution unquestionably favors the latter as the reliable indicator, owing to false interpretations of the presumptive test and to lack of accurate definition of fecal and nonfecal coliforms recovered from positive cases. The use of enterococci, however, did not provide as reliable an indicator as the pour-plate method. Third, the results with enterococci, in defining the probable source of pollution, are more precise. Experiments judiciously selected and simultaneously conducted revealed that the heat and heat-tellurite resistance tests, and the tetrazolium-reduction test, matched in relating 98.9% of available enterococci to an animal source. Negligible but vital discrepancies were obtained with the two odd strains which qualified as human-derived according to the heat and heat-tellurite resistance tests. The differential criterion of Skadhauge and Barnes, based on the failure of animal-derived enterococci to grow in the presence of a low concentration of potassium tellurite, did not apply to the other two methods, since 99.5% of the recovered strains were found tolerant to the specified tellurite concentration.
A series of pyridazino[3,4-d][1,3]oxazin-5-one derivatives were designed and synthesized through a versatile method. Reaction of chloro-ester 1 with sodium azide has afforded azido-ester 2 which reacted with triphenylphosphine to produce compound 3; amino-ester 4 was formed upon treatment of compound 3 with acetic acid 80%; this amino-ester 4 was then hydrolyzed to the amino-acid 5 which is considered the starting material. The approach involves treatment of pyridazinamino-acid 5 with acetic anhydride, benzoyl chloride, triethylorthoformate, ethyl chloroformate, diethyl oxalate, phthalic anhydride as well as succinic anhydride to yield pyridazino[3,4-d][1,3]oxazin-5-one derivatives 6, 8, 9, 10, 11, 12 and 13. The new synthesized compounds were confirmed by their infrared, mass spectrum and 1 H-NMR.
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