The behaviour of bacteria in the digestive tract / by Allan Macfadyen, M.D. Edin.

  • Macfayden, Allan, 1860-1907
Date:
[between 1885 and 1891?]
Catalogue details

Licence: Public Domain Mark

Credit: The behaviour of bacteria in the digestive tract / by Allan Macfadyen, M.D. Edin. Source: Wellcome Collection.

    10/30 page 420
    It will be sufficient to show that there is an arrest of develop¬ ment in order to prove the role the bile is assigned in the digestive tract. The following experiments are arranged to investigate germs as arrested in their development:— (a) The Bile alone.—Query: Has it an antiseptic action? Fresh ox bile was used both of neutral and weakly alkaline reaction. It was sterilised, and mixed with 7 per cent, gelatine in the proportions of 2 per cent., 5 per cent., and 10 per cent. Infected with germs according to usual methods, and therefrom plates, and also control gelatine plates. Temperature of 15° C. When control plates had grown, the bile plates wrere examined. Following organisms tested:— 1. Staphylococcus aureus. 2. Typhoid bacilli. 3. Micrococcus tetragenus. ’ 4; Anthrax bacilli. 5. Saprophytic bacilli. 6. Koch’s comma bacilli. 7. Finkler and Prior’s spirillus. 8. Micrococcus prodigiosus. jResults.—All grew as well as on the control plates, even with addition of 10 per cent, of bile. Conclusions.—The bile itself, in alkaline or neutral state, in no way arrests the development of micro-organisms. (b) Bile Acids.—Glycocholic and taurocholic acids. Query: Are they antiseptics with the power ascribed to them, and in the sense of the word that carbolic acid is ? Do they have a potent action on pathogenic and non-pathogenic germs, or, at least, a potent control over putrefactive processes, so that an important role can be assigned to them in one or other respect in the intestinal canal ? I sought here not to use putrefactive germs merely, but to have a variety, pathogenic and non-pathogenic, varying in nature and in susceptibility. I introduced twro new germs into the experiments. 1. Proteus vulgaris (Hauser, “Uber Faulniss Bacterien,” Yogel Leipzig, 1885). This is a putrefactive bacillus which rapidly liquefies the gelatine, and produces a very foetid smell. Hauser has assigned it a role in septicsemic processes. 2. Emmerich’s bacillus (Emmerich, Arckiv fur Hygiene, vol. ii., 1885). Emmerich believes, or believed it to be, the germ of cholera Asiatica. It is reputed to be very resistant. In these researches we must try to preserve natural conditions, and not to experiment with amounts of the acids which could hardly be present in the intestine at one time. It will be useful to try to form a mental picture of what occurs in the intestine. What influence has the acid chyme on the bile when discharged into the duodenum ?
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