126 



Scientific Proceedings (82). 



75 (1253) 



Soluble substance of pneumococcus origin in the blood and 

 urine during lobar pneumonia. 



By A. R. Dochez and O. T. Avery. 



[From the Hospital of the Rockefeller Institute for Medical Research, 



New York.] 



A specifically reacting substance of pneumococcus origin has 

 been demonstrated in the filtrates of young cultures of pneumo- 

 coccus, 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 anti pneumococcus 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 filtra- 

 tion, 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 



