130 



BACTERIOLYSINS AND HEMOLYSINS. 



Neisser and Wechsberg explain this phenomenon by the so-called 

 "deviation of the complement" They assume that in the serum of higher 

 concentration there are so many amboceptors that the bacteria cannot bind 

 them all. The amboceptors remaining free attach themselves to the com- 

 plement by means of their complementophile group just as the already 

 bound amboceptors have done. Thus, a part of the complement is deviated 

 from the bacteria and only an incomplete bacteriolysis takes place. 



The theory of complement deviation does not in the opinion of the author withstand 

 critical examination. Particularly the evidence brought forward by Bordet and Gengou 

 that the affinity of complement for the bacterium + amboceptor complex (Sensitized 

 bacterium) is considerably greater than for free amboceptor, militates against the view 

 of Neisser and Wechsberg. 



It is possible that agglutination may account for the phenomenon of deviation of the 

 complement in that the agglutinated masses of bacteria afford a more resistant barrier 

 to the action of the bacteriolysins. The author has now and then observed an analogous 

 phenomenon in hemolytic experiments; strong doses of hemolysin were less effective 

 than moderate ones, and in these cases the momentary hemagglutination was readily 

 visible. Also, by titrating bactericidal sera in animal experiments, it has been found 

 that moderate doses often afforded the greatest protective action. 



For the practical application of the plate culture method, knowledge of 

 the following data is important, as it is necessary to consider the difference 

 between the bactericidal titer of sera of normal and of typhoid patients. 

 According to Korte and Steinberg the bactericidal titer was 



The bactericidal titer does not run strictly parallel either with aggluti- 

 nation or the Pfeiffer experiments. It falls toward the end of the disease 

 and is low during convalescence. 



Besides being used in typhoid, the plate culture method has been employed for experi- 

 mental purposes in cholera and dysentery; in these diseases, however, it possesses no 

 clinical diagnostic significance. 



Concerning bacillus paratyphosus, the views of different authorities are widely at 

 variance. While some obtained very good results, similar to those found in typhoid 

 fever, Topfer and Jaffe could demonstrate no bactericidal power whatever in vitro. 

 This difference can be explained only by the differences in sera. 



