Soluble substance of pneumococcus origin in the blood and urine during lobar pneumonia

Abstract

A specifically reacting substance of pneumococcus origin has been demonstrated in the nitrates of young cultures of pneumococcus, and also in the blood serum and urine of patients during the course of lobar pneumonia. In bacteria-free filtrates of broth cultures of pneumococcus there is present a soluble material which gives a specific precipitin reaction with antipneumococcus serum. The filtrates from the different types of pneumococcus show the same specificity of reaction with immune serum as do the original cultures from which they are derived. The soluble substance present in the filtrates is undoubtedly of bacterial origin. That it is a product of the life processes of the pneumococcus and not due to its disintegration is shown by the fact that it is present in considerable amounts during the early stage of development of the culture when the organisms are growing at their maximum rate and undergoing little or no cell destruction as indicated by their growth curve.

The demonstration of the formation of this soluble substance in cultures of pneumococcus growing actively in vitro suggested the probability of its production in experimentally infected animals and in human beings suffering from lobar pneumonia. If rabbits are infected intraperitoneally with pneumococcus a substance specifically precipitable with antipneumococcus serum can be demonstrated in their blood serum, freed from bacteria by filtration, from within two to six hours following the time of infection. This soluble specific substance is also present in the blood serum during the course of lobar pneumonia in man and gives a precipitin reaction with antipneumococcus serum corresponding in type to the organism with which the individual is infected. This soluble precipitable substance is less frequently present in demonstrable quantities in human serum than in the serum of experimentally infected animals.