Some points in connection with the pathology and epidemiology of swine fever / by J.P. MʻGowan.

  • MʻGowan, J. P. (John Pool)
Date:
1915
Catalogue details

Licence: Public Domain Mark

Credit: Some points in connection with the pathology and epidemiology of swine fever / by J.P. MʻGowan. Source: Wellcome Collection.

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    With regard to the pathogenicity to guinea-pigs when injected intraperitoneally, both large and small colonies failed to kill guinea-pigs in certain cases, and in regard to both when the guinea-pig in such cases was killed, the findings in the peri- toneum could be the same—namely, the presence of numerous pus cells and the entire absence of bacteria, although a large number of these had been injected. When, on the other hand, as occurred frequently, the intraperitoneal injection of either type killed the guinea-pig, the findings in both could again be the same—namely, a large amount of clear exudate, swarming with bacteria and with practically no leucocytes. In both cases the organisms present in the fluid were typical bipolar bacilli. As regards the growth on stab gelatine, none of them pro- duced liquefaction, and, as mentioned above, sometimes a large colony produced hardly any growth in this medium, while, on the other hand, it sometimes happened that a small colony produced a good growth. As regards the reactions of these various organisms on the various sugars, &c., and other media, it can only be said that in this respect no attempt at a general law can be formulated. The reactions of the large colonies on the sugars no more resemble one another than they resemble the reactions of the small colonies. The same may be said also of the small colonies. The only possible generalisation that might be made is, that this very erratic behaviour of members of the two groups constitutes one of their greatest resemblances to each other. The general facts, therefore, derivable from a consideration of Table I. are :— (1) All the organisms are bipolar cocco-bacilli. (2) All were obtained from typical cases of swine fever. (3) They were obtained either as pure original cultures of small and large colonies, or as mixtures of these. No other organisms except these two were obtained in any of the cultures. (4) One of the greatest resemblances between the members of the two groups is their capacity for variation. (5) These two groups shade one into the other. The small colonies undoubtedly represent Bacillus suisepticus, and the question comes to be, what is the nature of the large colonies? They may be—
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