Experimental Pneumococcal Infection Research Articles

CHANGES IN HUMORAL IMMUNITY OCCURRING DURING THE EARLY STAGES OF EXPERIMENTAL PNEUMOCOCCUS INFECTION

A study was made of the changes in humoral immunity occurring during the early phases of experimental pneumococcus infection in the dog and cat. The methods devised by Robertson and Sia were employed to demonstrate the presence of anti-pneumococcus properties in the serum of animals naturally resistant to this micro-organism. It was found that with a generalized and overwhelming infection accompanied by early blood invasion, there was a prompt and rapid decrease in the concentration of natural humoral immune bodies which frequently disappeared entirely by the time of death. This same early diminution of humoral immune substances, opsonins, agglutinins, and pneumococcidal-promoting bodies was observed in animals that survived a moderately severe generalized infection but the concentration of immune bodies rose again with the onset of recovery. The decrease in concentration of humoral immune substances during a severe generalized infection appeared to be due to the combination of "S" substance with the normal immune bodies. When the pneumococcus infection was more localized as in the case of true lobar pneumonia a quite different sequence of events was observed to occur. Several animals, in which extensive lobar pneumonia was produced, showed the presence in quantity of humoral immune bodies in the blood throughout the course of an infection terminating fatally. These findings suggest that after the inception of pneumococcus infection in the dog and cat the chief function of natural anti-pneurnococcus substances in the blood is to limit or prevent blood invasion. When pneumococcic infection is localized these circulating antibodies appear to have little effect either in preventing the spread of the process or determining the outcome of the disease.

Changes in Humoral Immunity Occurring During the Early Stages of Experimental Pneumococcus Infection.

A study was made of the changes in humoral immunity occurring during the early phases of experimental pneumococcus infection in the dog and cat, employing the methods devised by Robertson and Sia1 for demonstrating the presence of anti-pneumococcus properties in the serum of animals naturally resistant to this microorganism. It was found that with a generalized and overwhelming infection accompanied by early blood invasion, there was a prompt and rapid decrease in the concentration of natural humoral immune bodies which frequently disappeared entirely by the time of death. This same early diminution of humoral immune substances, opsonins, agglutinins, and pneumococcidal promoting bodies was observed to occur in animals recovering from a moderately severe generalized infection with the difference that the concentration of immune bodies began to rise coincident with the onset of recovery. The decrease in concentration of humoral immune substances during a severe generalized infection appeared to be due to t...

BLOOD CHLORIDES IN CONDITIONS ASSOCIATED WITH PNEUMONIA

Attempts have been made in dogs to lower the serum chlorides by means of various procedures. Of these the withholding of food, anoxemia, tissue destruction, anaphylactic shock, leucocytosis, and fever yielded negative results. Ingestion of large amounts of water lowered the chloride level independently of body temperature. The chloride drop under these circumstances could not be accounted for by excretion and appeared to run parallel with an increase in the serum water content. Experimental pneumococcus infection in two animals reduced the serum chloride concentration.

A Study of the Mechanism of Recovery from Experimental Pneumococcus Infection

A Study of the Mechanism of Recovery from Experimental Pneumococcus Infection

A STUDY OF THE MECHANISM OF RECOVERY FROM LOBAR PNEUMONIA

Employing a method devised for the investigation of natural immunity and experimental pneumococcus infection, a study has been made of the serum immune changes occurring during the course of lobar pneumonia due to Pneumococcus Types I and II and Group IV, in man. It was found that at the time of crisis or lysis the blood serum acquired constantly the property of promoting pneumococcus killing to a relatively marked degree. Other evidences of antipneumococcus reaction-mouse protection, opsonins, and agglutinins-were also demonstrable in the blood at this time. These immune changes appeared in the majority of cases at the beginning of recovery and failed to occur when the disease terminated fatally. The fact that these observations in human cases are practically identical with previous findings in the experimental disease in cats, enhances considerably the significance of the development of serum immune bodies at the time of crisis since in the experimental animal it was possible to show that the acquisition of passive immunity was associated with greatly increased antipneumococcus resistance.

A STUDY OF THE MECHANISM OF RECOVERY FROM EXPERIMENTAL PNEUMOCOCCUS INFECTION

A study was made of the blood of cats and rabbits during experimental pneumococcus infection with a view to ascertaining the relationship of acquired immune properties to the mechanism of recovery. Observations were directed chiefly towards the detection of pneumococcidal promoting substances, but the other manifestations of anti-pneumococcus reaction were studied as well. It was found constantly that the serum of animals recovering from infection possessed the power to promote the destruction of highly virulent pneumococci in rabbit serum-leucocyte mixtures which mixtures of themselves have no growth inhibitory action. Furthermore, the presence of this serum immunity was associated with a marked increase in acquired resistance to the pneumococcus. In cats which were studied in the most detail the pneumococcidal promoting power of the serum as well as the opsonic, agglutinative, and mouse protective activities became demonstrable at the time of recovery and their appearance in the serum always marked the termination of blood invasion. These immune reactions were found to be type-specific. The animals which succumbed failed to develop detectable serum immune properties and showed persistent blood invasion. The degree of leucocytosis did not appear to bear any constant relation to the outcome of the disease. The significance of these findings is discussed.

The occurrence of antipneumococcus substances in the blood serum in lobar pneumonia.

With a method1 previously described for carrying on growthinhibition tests with the pneumococcus, it was shown that a mixture of serum and leucocytes from naturally resistant animals (cats or dogs) was capable of inhibiting the growth of pneumococci in considerable numbers, whereas a serum-leucocyte mixture from a susceptible animal (rabbit) was found to have no such action. It was possible, however, to passively confer growth-inhibitory and pneumoccidal powers on serum-leucocyte mixtures of the latter animal by adding a very small quantity of a homologous antipneumococcus serum. By comparing different immune sera the degree of growth inhibition thus obtained paralleled closely their protective action for mice. In a subsequent investigation on experimental pneumococcus infection, it was found that recovery was invariably accompanied by the development in the serum of the infected animals of immune substances, which could be demonstrated by the occurrence of pneumococcus growth-inhibition when such serum w...

Observations on the chemo‐therapy of bacterial infections, with special reference to experimental pneumococcus infection

The Journal of Pathology and BacteriologyVolume 22, Issue 3 p. 265-269 Article Observations on the chemo-therapy of bacterial infections, with special reference to experimental pneumococcus infection C. H. Browning, C. H. Browning Bland-Sutton Institute of Pathology, the Middlesex HospitalSearch for more papers by this authorR. Gulbransen, R. Gulbransen Bland-Sutton Institute of Pathology, the Middlesex HospitalSearch for more papers by this author C. H. Browning, C. H. Browning Bland-Sutton Institute of Pathology, the Middlesex HospitalSearch for more papers by this authorR. Gulbransen, R. Gulbransen Bland-Sutton Institute of Pathology, the Middlesex HospitalSearch for more papers by this author First published: 1919 https://doi.org/10.1002/path.1700220310Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume22, Issue31919Pages 265-269 RelatedInformation

THE CHEMOSEROTHERAPY OF EXPERIMENTAL PNEUMOCOCCAL INFECTION

1. A single small dose of ethylhydrocuprein (optochin base), which by itself has practically no protective effect against experimental pneumococcal infection in mice, is capable of increasing the threshold value of the type homologous antipneumococcus serum at least fifty times. 2. This effect is proportionately many times greater than a simple summation of the protective effects of these two bodies. 3. No such effect is obtained when the antiserum used is one produced against a strain of pneumococcus from a group other than that to which the infecting pneumococcus belongs.

THE ACTION OF ETHYLHYDROCUPREIN (OPTOCHIN) ON TYPE STRAINS OF PNEUMOCOCCI IN VITRO AND IN VIVO, AND ON SOME OTHER MICROORGANISMS IN VITRO

1. Ethylhydrocuprein hydrochloride in very high dilution inhibits the growth of, and in 18 hours kills, representatives of all four groups of pneumococci in vitro. The killing effect is generally seen in somewhat lower dilutions than the inhibiting effect. No constant or considerable difference is seen in these actions on representatives of the four groups of the pneumococci. The action of ethylhydrocuprein hydrochloride on the pneumococci in vitro is so strongly specific that it may possibly be used as a test for a true pneumococcus. 2. The inhibitory or killing effects of ethylhydrocuprein hydrochloride in vitro on bacteria other than pneumococci are slight or absent. The effects are greater on streptococci than on any other organisms examined, but are still much less than on the pneumococci. This action distinguishes between the streptococcus group, including Streptococcus mucosus sometimes found in normal mouths, on the one hand, and the true pneumococcus (including Pneumococcus mucosus), on the other. 3. Quinine hydrochloride inhibits the growth of, and kills the pneumococcus in vitro; much stronger concentrations, however, are necessary than in the case of ethylhydrocuprein. This effect of quinine hydrochloride is also seen on other organisms, but in a less degree. 4. Ethylhydrocuprein (optochin base) has a well marked protective action against experimental pneumococcal infection in mice in the case of type strains of all four groups of pneumococci; this protective action may be efficient against many multiples of the minimum lethal dose.