Upon the intracellular constituents of the typhoid bacillus / by Allan Macfadyen and Sydney Rowland (from the Jenner Institute of Preventive Medicine, London.).

  • Macfayden, Allan, 1860-1907
Date:
1903
Catalogue details

Licence: In copyright

Credit: Upon the intracellular constituents of the typhoid bacillus / by Allan Macfadyen and Sydney Rowland (from the Jenner Institute of Preventive Medicine, London.). Source: Wellcome Collection.

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    ficient to lead us to the conclusion that in no case was an extracellula toxin developed comparable in any way to those obtained from pure cul tures of undoubtely extracellular toxin-producing organisms, e. g. tht diphtheria bacillus, etc. It did not appear that this line of investigatioi would be likely to lead to any practical results. The very large numbe of experiments made with the most natural soils obtainable had not beei successful in demonstrating the presence in cultures of the typhoid bacillus of any definite toxin of likely value for immunising purposes. II. Experiments with reference to an intracellular typhoid toxin. The experiments having failed to establish the presence of any definiti extracellular toxin, it became necessary to search within the typhoid or ganism itself for the missing toxin. The research was thus directed no to the products of the typhoid bacillus, but to the organism itself am its intracellular constituents. For this purpose the endeavour was madi to obtain the fresh unmodified cell plasma of the organism and the metho( originally employed was as follows: The virulent typhoid bacilli wen grown on the surface of nutrient agar in flat rectangular bottles, eacl giving a surface of 200 sq. cm; one hundred such culture bottles weri required in order to yield a growth sufficient for trituration by the methot that was in the first instance adopted. After cultivation for about 36 hours at blood heat, the bottles on being washed out with salt solution, yielde* about one litre of a thick emulsion of the bacilli. The bacilli were sepa rated from the emulsion by means of a high speed centrifuge, and weri at the same time thoroughly washed free of possible excretory products b; repeated additions of physiological salt solution. The washed and separate* bacilli were then mixed with fine silver sand and triturated in a cold jacketed metal cylinder by means of small vanes revolving at a hig] velocity. The intercollision of sand particles and bacilli resulted in thi rupture of the bacterial cells, and the process usually occupied from threi to four hours. The resultant mass was filtered through Kieselguhr witl the aid of a hydraulic press. The filtrate represented a rich water solution or suspension of the intracellular constituents of the typhoi* bacillus in so far as these were capable of passage through the Kiesel guhr. There remained at the end of the pressing a hard cake of Kiesel guhr, which was found to contain a considerable amount of retained al buminous and other organic substances. Repeated extractions of this cake made with glycerine and with a solution of carbonate of soda, demonstrate* that the Kieselguhr cake contained physiologically active constituents o the typhoid organism. There had undoubtedly been held back intracellulai elements of possible importance to the experiments we desired to earn out. The entire operation lasted about six hours and the average yiel* of juice from the first pressing was about 8 ccm. An account has already been given of the experiments made with such juices upon guinea pigs and rabbits with a view to testing their toxicity and immunising properties against the baci 11 us typhosus. It was found that the fluid, injected ii doses of 1, 0.5 and 0.2 ccm completely protected the experimental animals against one to ten lethal doses of virulent typhoid bacilli, and the pro tection following one such injection lasted about four weeks. The results were identical whether a first, second or third pressing of the juice througl the Kieselguhr was employed. The juices preserved their immunising pro perties as regards the typhoid bacillus for a considerable period of time