ANTI-ENZYME IMMUNITY 263 



matis-maligni were capable of hydrolyzing proteins in the presence of 

 normal serum. These facts suggested to them that this characteristic 

 is an important one in pathogenesis, enabling the members of this 

 group to establish a foothold in the body of the host, and to obtain 

 those breakdown products of protein which are their main source of 

 energy. In comparing the proteolytic activities of rough and patho- 

 genic CI. hystolyticum strains, they found that the rough strain, as well 

 as trypsin, were inhibited by normal serum; in contrast, the patho- 

 genic strain was not inhibited. 



Immune sera prepared by the injection of filtrates of smooth 

 CI. histolyticum into rabbits inhibited the enzymes of this organism. 

 This inhibition was specific. The anti-proteinase immune serum to this 

 strain did not inhibit the proteolytic activity of CI. sforogenes, CI. 

 welchii, or even the rough strains of CI. histolyticum. This experi- 

 ment was performed with antiserum which had stood sufficiently long 

 in the cold to have lost its ability to inhibit the proteinases of the 

 non-pathogenic organisms. While the trypsin-inhibitor was shown to be 

 found in the albumin fraction by electrophoretic fractionation, the im- 

 mune body against bacterial proteinase was found in the globulin 

 fraction. 



The question as to whether there is a causal relationship between 

 the ability of certain bacteria to resist the inhibition of normal serum 

 and pathogenesis cannot as yet be stated with certainty. However, the 

 results of the studies of the above mentioned several investigators are 

 presented in Table XIV (p. 262) to enable the reader to evaluate for 

 himself the available data. 



F. FIBRINOLYSIS 



1 . Serum Proteinase as Fibrinolytic Enzyme and the Role 

 of Bacterial Fibrinolytic Factor 



a. Comment on Nomenclature. The dissolution or digestion of a 

 plasma clot or fibrin with or without the participation of bacterial 

 factors is known as fihrinolysis. The bacterial factors which participate 

 in fihrinolysis have been known as fihrinolysins. It has now been pro- 

 posed that new terminologies be adapted. 



The enzyme which is found in serum and brings about the lysis of fi- 



