Anærobic infection in animals : discussion on Professor Gaiger's paper Mr. Dalling's views.

  • Dalling, Thomas.
Date:
[1924?]
Catalogue details

Licence: In copyright

Credit: Anærobic infection in animals : discussion on Professor Gaiger's paper Mr. Dalling's views. Source: Wellcome Collection.

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    grown on a medium containing meat, become resistant to beat, for in attempting to isolate cultures from a mixture I have been able to beat sucb meat cultures for fifteen minutes at 80° C., and recover cultures of B. welchii. Spores may be demonstrated by tbe incubation of tbe whole carcase of a guinea-pig dead from a B. welchii infection. Tbe organism produces a fairly potent toxin in young cultures. I usually work witb a culture grown 12—15 hours at 37° C., for tbe production of tbe best toxin. In my experience tbe toxin is not stable, and if kept even in an ice room it is quickly reduced in potency. To test tbe toxicity of B. welchii filtrate we use mice, inoculating them intravenously. An example of sucb a test is given in Table VIII. Table VIII. Mouse. Toxin. Result. 1 0*25 c.c. + overnight. 2 0-25 c.c. + overnight. 3 0T c.c. + overnight. 4 0T c.c. + overnight. 5 0-05 c.c. + 36 hours. 6 0-05 c.c. + 36 hours. 7 0-025c.c. + 36 hours. 8 0-025c.c. — 9 0-01 c.c. — 10 0*01 c.c. — 4- 1 = Died. — = Lived. During our work on lamb dysentery, we made an anti-toxin for B. welchii, and tbe occasion arose to test serum of normal horses for tbe presence of sucb anti-toxin in tbe hope of finding one witb an appre¬ ciable quantity and which, therefore, could be immunised rapidly. Tbe intradermic test was carried out on guinea-pigs, using a mixture of toxin and horse serum. Tbe toxin produces a circular raised swelling which in time becomes necrotic and sloughs. A mixture of anti-toxin and toxin fails to produce sucb a lesion. Table IX. shows tbe results of intradermic injections of mixtures of a known toxin and normal horse sera.
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