The bacteria in scarlatinal and normal throats / Gustav F. Ruediger.

  • Ruediger, Gustav F.
Date:
1906
Catalogue details

Licence: In copyright

Credit: The bacteria in scarlatinal and normal throats / Gustav F. Ruediger. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    ^0 grams of pure inulin in 1,000 c.c. of distilled water. Add 20 c.c. of a 5 per cent solution of pure litmus and tube, putting 2 c.c. of the mixture into each tube, and sterilize in the autoclave. After sterilization, add (with a sterile pipette) 2 c.c. of sterile heated ascites fluid® or preferably heated beef serum, to each tube and incubate for 24 hours before using. The beef serum was collected without taking any special precautions, but was diluted with an equal volume of water and passed through a large Berkefeld filter, drawn off into 50 to 100 c.c. tubes and heated to 65° C. for one-half hour on two successive days This medium was preferred to Hiss^ serum-water be- cause it was found that some pneumococci and some streptococci which have been recently obtained from blood cultures do not grow well in the latter. In the early part of this work no litmus inulin-agar plates were used but pneumococci were looked for among the green colonies in blood-agar plates. In those cases subcultures were made and studied from 10 to 12 green colonies. Organisms were classed as typical pneumococci only when they were found to be: 1. Gram-positive cocci which grew chiefly in pairs on blood-agar or serum- agar slants; and 2, which fermented inulin; and 3, pro- duced green or slightly hemolyzing greenish colonies in blood-agar plates. In the litmus inulin-agar plates most pneumococci pro- duce red colonies which are easily recognized on the blue background, and as practically no other mouth bacteria produce red colonies in this medium® it is easy to isolate pneumococci from the mouth and throat with the aid of these plates. Subcultures were, however, always made from 2 or 3 red colonies, and the organisms positively identified. In no instance have I isolated an organism by this method which could not be classed as a pneumo- coccus, although some of these organisms form chains of considerable length in some liquid media and do not seem to have a well formed capsule. RESULTS. A total of 154 throat cultures were made and exam- ined as follows: Normal, 51; scarlatina, 75; measles, 14; tonsillitis, 5; pneumonia, 5, and pharyngitis, 4. The 5. Great care must be observed not to use ascites fluid which contains fermentable carbohydrates. Each lot must be tested with organisms that are known to have great fermentative powers and if acid is produced It must not be used. 6. See .Journal of Infectious Diseases, 1906, vol. iii, p. 183.