Volume 3

Final report of the Royal Commission appointed to inquire into the relations of human and animal tuberculosis. Part II. Appendix. : 1.- Certain human viruses of irregular type. 2.- The excretion of tubercle bacilli in the milk of animals. 3.- Swine tuberculosis. 4.- Immunity.

  • Great Britain. Royal Commission on Tuberculosis (Human and Bovine)
Date:
1904-1913
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Final report of the Royal Commission appointed to inquire into the relations of human and animal tuberculosis. Part II. Appendix. : 1.- Certain human viruses of irregular type. 2.- The excretion of tubercle bacilli in the milk of animals. 3.- Swine tuberculosis. 4.- Immunity. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    MODIFICATION EXPERIMENTS. INTRODUCTION. The experiments in this report have been made with a view to ascertain whether the apparently stable characters and properties of a variety of strains of tubercle bacilli can be altered by exposure to the influence of animal hosts of different species. The cultures of tubercle bacilli used have been isolated and studied in the research on natural tuberculosis in different species of animals other than man and include avian tubercle bacilli from both birds and pigs, bovine tubercle bacilli, and tubercle bacilli of slight virulence for the calf and rabbit (bacilli corresponding to the human tubercle bacillus of Group II.). The experimental animals employed have usually been such as might be presumed to be refractory to the particular cultures which it was sought to modify. For example, avian tubercle bacilli have been passed through the bodies of various mammals, and mammalian tubercle bacilli through fowls ; slightly virulent tubercle bacilli obtained in culture from pigs and an antelope have been recovered after passage through calves and rabbits. Addi- tional experiments have been made to test the effects of residence in dogs on bovine tubercle bacilli, and certain passage experiments on chimpanzees and baboons have been completed. In many instances the passage experiments have been performed with a number of animals in series, in others the bacilli used in the experiment have been recovered in culture after a single residence in the animal body. SUMMARY OF RESULTS. (a) EXPERIMENTS WITH AVIAN TUBERCLE BACILLI. Two passage experiments on calves lasting from May 30, 1907, to May 20, 1908, have been made with Virus A. X. The first calf was inoculated intravenously with culture and the passage was continued in two series of calves with emulsions of either liver or spleen ; all the calves were inoculated intravenously except for the final calves in each series which were inoculated subcutaneously. The details can be seen most readily by referring to the tables, pages 392—395. Numerous cultures were isolated from animals of various species in the course of the experiments and except for a single instance none showed any change in characters or increased virulence for guinea- pigs. The exception was Calf 574, a final calf in Passage No. 2, which showed when killed in good health after 109 days local tuberculosis and a caseous nodule in a bronchial gland. From the bronchial gland a culture was isolated which grew like a bovine tubercle bacillus and was virulent both for rabbits and guinea-pigs ; from the prescapular gland a typical avian culture identical with that inoculated was obtained. The site of the lesion from which the mammalian culture was isolated suggests that the calf had been accidentally infected. Two passage experiments were made with rabbits and guinea-pigs, the bacilli being passed from animal to animal in emulsions of tuberculous tissues ; the rabbits were introduced alternately in order to increase the number of active tubercle bacilli available for inoculation into the guinea-pigs. Of these two experiments one with Virus A. V. (page 396) lasted from July 4, 1906, to November 6, 1908, and the two guinea-pigs finally inoculated showed in one case a single nodule in an inguinal gland and in the other no tuberculosis, so that cultures could not be obtained from them, but the culture from the preceding animal, a rabbit, was avian in character. The other experiment, with Virus P. XXL, (page 397) lasted from May 22, 1906, to November 6, 1908. Numerous cultures, were isolated from animals in both these passage experiments and in none was there any change in characters or increase in their virulence for the guinea-pigs. In addition to the passage experiments mentioned above cultures have been obtained from lesions in many of the animals inoculated for test purposes with avian tubercle bacilli and the details concerning the duration of life of the animals and the sources of the cultures investigated have been collected into the form of tables (pages 398--402). The results in brief are as follows. 34684 3 H 2