. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. MYCOBACTERIACEiE: THE BACILLUS OF DIPHTHERIA 3OI may occur as a granular sediment, as a diffuse cloudiness or as a pellicle on the surface, depending upon the reaction and pepton content of the medium and the vigor of growth of the culture. The growth on the surface produces the best yield of toxin. Acid is produced in dextrose broth. The organism is killed when moist by heating to 60° C. for 20 minutes. It is fairly resistan
. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. MYCOBACTERIACEiE: THE BACILLUS OF DIPHTHERIA 3OI may occur as a granular sediment, as a diffuse cloudiness or as a pellicle on the surface, depending upon the reaction and pepton content of the medium and the vigor of growth of the culture. The growth on the surface produces the best yield of toxin. Acid is produced in dextrose broth. The organism is killed when moist by heating to 60° C. for 20 minutes. It is fairly resistant to drying and has been found alive in bits of dry diphtheritic mem- brane after four months. Roux and Yersin in 1888 filtered broth cultures of the diph- theria bacillus through porcelain filters and found the filtrate. Fig. 123.—Colonies oi B. diphtheriiB on agnr. X200. (After Park and Williams.) extremely poisonous. By injecting it into animals they were able to produce the signs of local and general intoxication which are observed in the natural disease. A favorable medium for toxin production is a veal broth containing 2 per cent pepton and having a titre of 9 ^ of normal sodium hydroxide above the neutral point to Htmus. It should be placed in flasks in a thin layer to allow abundant air supply. Incubation for from 5 to 10 days gives the maximum toxicity. The filtrate from such a culture may kill a 250 gram guinea-pig in a dose of Less powerful toxin is frequently obtained, so that sometimes ' Per 1000 of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original MacNeal, Ward J. , 1881-1946; Williams, Herbert Upham, 1866-. Philadelphia, P. Blakiston's Son & Co.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbacteri, bookyear1920
