Lord (1, 2) has reported t h a t exudates of pneumococcus infection show hydrogen ion concentrations greater than the blood serum by comparative measurement. With the dialysis method he'was usually able to demonstrate acidity of marked degree in pneumonic sputum, empyema pus, and in exudates taken at autopsy from the solidified lungs of fatal cases of lobar pneumonia and from those of dogs with experimental pneumococcus pneumonia. In confirmation of Lord's observations, Takahashi (3) showed with electrometric methods that in pneumococcus empyema, the hydrogen ion concentration of the pus becomes progressivel)r increased from approximately pH 7.00 at the onset, to values as great as pH 5.71 in the later stages. Takahashi found in addition that the empyema pus contained only 0.05 to 0.02 per cent of sugar.Physicochemical changes in inflammation were first" described by Opie (4) who titrated a decrease in alkalinity of exudates from the pleural cavities of dogs previously injected with irritants. Lord (1, 2), Koldajew (5), Golinow (6), and Menkln (7) have with different methods found acidity in exudates from infections due to a variety of bacteria. By further studies of inflammation, Kempner (8) has shown that in the fluid of cantharides skin blisters, carbonic and lactic acids become increased in concentration with the aggregation of leucocytes, while the base and sugar are proportionately diminished in comparison with the blood. Light from another angle has been thrown upon the origin of these physicochemical changes by Menkin (9) and others. From the injection of dyes, the latter workers have adduced evidence to indicate that in focal inflammation, capillary permeability is increased, whereas diffusion from the lesion into the surrounding tissues and blood stream is reduced by the coagulation of fibrin and plasma in the capillaries and lymphatics. Thus, it appears that localized inflammation generally is characterized by an accumulation of acids with a corresponding depletion of base and 659 on
Certain interesting facts have been obtained regarding the action of normal swine serum, but in the light of present knowledge it is not easy to interpret them. It has been found that the normal serum possesses the property of protecting mice from infection with virulent pneumococci, and of agglutinating virulent S pneumococi and also avirulent R pneumococci. The protective action of the serum is specific, that is, absorption of the serum with pneumococci of one type removes or destroys only the property of the serum which is responsible for its protective action against pneumococci of that particular type, leaving the serum still active against pneumococci of other types. In this particular, therefore, the swine serum resembles a polyvalent antipneumococcus serum produced by artificial immunization. In other particulars, however, the swine serum differs from that produced byartificialimmunization. Inthefirstplace, theprotectiveaction exhibited by normal swine serum against type-specific pneumococci is very slight compared with that of animals which have been artificially immunized, even though the latter have received only a very few injections of the specific antigen. Moreover, the protective properties of the swine serum are destroyed by heating to 65°C., and they disappear after a few weeks, even if the serum is kept in the cold. Also the protective action of the serum is diminished after the serum has been mixed with non-type-specific avirulent R pneumococci and the latter have been removed by centrifugalization. A further difference between the action of swine serum and that of the antipneumococcus serum produced by artificial immunization is that although the swine serum is type-specific in its action in protecting mice, nevertheless when this serum is mixed with a purified type-specific polysaccharide, neither precipitation nor fixation of complement results; and, finally, the action of the serum in protecting mice against pneumococci of a particular type is not inhibited by the addition of the homologous polysaccharide to the serum. These latter facts relating to the specific polysaccharide, and especially the fact that the specific protective action disappears after applying the so called absorption technique with non-type-specific organisms, are most difficult to harmonize with the present conceptions of the nature of pneumococcus type specificity. It is not proposed at the present time to offer any theoretical explanation of these phenomena. The studies have also confirmed the observations of Robertson and Sia, that, if a proper technique be employed, normal swine serum exhibits the property of agglutinating type-specific pneumococci, and that the agglutinins for pneumococci of one type may be specifically absorbed, leaving those for pneumococci of other types unchanged. Finally, it has been shown that swine serum causes the agglutination of avirulent R pneumococci. This property of the serum is not destroyed by heating at 65°C., and therefore probably depends on factors other than those responsible for the agglutination of S pneumococci, and for the protective action of the serum in mice.
In a preceding communication (1) we have reviewed the accumulated evidence and presented additional data to indicate that a definite degree of acidity occurs in the lesions of pneumococcus infection. The r61e of the acidity in the lesions of pneumococcus infection is not as yet clearly understood. That acidity in vitro exerts a bacteriostatic effect upon the pneumococcus was proven by the studies of Demby and Avery (2), and Lord and Nye (3, 4), which showed that in broth, hydrogen ion concentrations greater than pH 6.80 not only inhibit growth but within a short time produce death of this bacterium. However, Morgan and Avery (5) have shown that the range of hydrogen ion concentrations at which pneumococcus growth can be initiated may be extended to a degree of acidity as great as pH 6.2 in broth by the addition of fresh unheated plant tissues. Possible evidence that acidity may be less active in inhibiting the growth of pneumococcus in animal tissue fluids is afforded by the observations of Felton and Dougherty (6) who were able to maintain growth of this microorganism in milk at pH 5.00, when adjusted with hydrochloric acid.The present paper is a report of studies on the effects of acidity upon the growth of the pneumococcus in culture media containing tissue fluids or animal proteins. Materials and MethodsCultures.--The findings reported were obtained with a standard strain of Type I Pneumococcus which was maintained at maximal virulence by mouse passage during the course of the experiments.Culture Media.--Beef infusion broth was prepared with neopeptone (Difco),
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.