Infection and resistance : an exposition of the biological phenomena underlying the occurrence of infection and the recovery of the animal body from infectious disease, with a consideration of the principles underlying specific diagnosis and therapeutic measures / by Hans Zinsser.

  • Zinsser, Hans, 1878-1940.
Date:
1923
Catalogue details

Licence: In copyright

Credit: Infection and resistance : an exposition of the biological phenomena underlying the occurrence of infection and the recovery of the animal body from infectious disease, with a consideration of the principles underlying specific diagnosis and therapeutic measures / by Hans Zinsser. Source: Wellcome Collection.

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    tlieorv if the bactericidal action of the blood (for anthrax bacilli) could be shown to be more potent in immune than in susceptible animals. Metchnikoff11 himself, taking this point of view, called attention to the fact that the blood serum of rabbits, animals that are highly susceptible to anthrax, is more powerfully bactericidal for these micro-organisms than is the blood of dogs or even that of immunized calves, both of which are much more resistant than are rabbits. Nuttall answered this by reporting that the blood of anthrax-immunized calves is actually more powerfully bactericidal than is that of normal calves. Although this argument of Nuttall was perfectly valid in principle, it exerted little influence on opinions at this time because anthrax happens as a matter of fact to belong to that group of infections in which bactericidal protection is actually secondary to phagocytic, and Lubarsch could show that the differences observed by Nuttall were often less than those obtaining between specimens of blood taken from individual normal rabbits. Lubarsch himself, then, in carefully planned experiments, showed that rabbits and cats could be killed with quantities of anthrax bacilli far less than the number which the extravascular blood of these animals can destroy. He concluded that the resistance, in these cases at least, is certainly not parallel with the bactericidal properties of the blood, and suggested the possibility that the intra- vascular blood does not possess bactericidal power to the same degree in which it is possessed by the extravascular plasma or serum. This point, first raised by Lubarsch- -namely, the possibility of a differ- ence between the intravascular blood and the extravascular blood serum or plasma in bactericidal functions—soon became one of the focal points of the controversy, since Metchnikoff, admitting flic bactericidal power of the shed blood, assumed that this was purely the result of substances given off by the leukocytic cell-bodies after extravascular injury. The Metchnikoff school defended its premise by the dual method of attempting on the one hand to establish a parallelism between phagocytic activity and natural resistance, and, on the other hand, by showing that the cell-free blood serum of naturally resistant ani- mals often furnished an excellent culture medium for the bacteria in question. Thus Wagner showed that anthrax bacilli grow well in the blood of fowls at 42° C., and Metchnikoff himself called attention to the fact that pigeons’ blood is an excellent medium for the cultivation of the Pfeiffer bacillus, whereas the living pigeon is entirely insusceptible to influenzal infection. Arguments based on such observations, however, have lost much of their original webdit, for we have sinee then learned more about the delicate quantitative conditions and the difficulties of accurate measurements obtaining in