DEVIATION OF COMPLEMENT 



143 



concentration there are so many amboceptors that the bacteria cannot 

 bind them all. The amboceptors remaining free attach themselves to the 

 complement 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 with- 

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

 Gengou that the affinity of complement for the bacterium -famboceptor complex (Sen- 

 sitized 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 analo- 

 gous phenomenon in hemolytic experiments; strong doses of hemolysin were less effect- 

 ive 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 



In typhoid fever the bactericidal titer does not run strictly parallel 

 either with agglutination or the Pfeiffer experiments. It falls toward the 

 end of the disease and is low during convalescence. 



Besides its use in typhoid fever, the plate culture method has been employed for 

 experimental purposes in cholera and dysentery; in these diseases, however, it possesses 

 no clinical diagnostic significance. 



Concerning bacillus paratyphosus B, 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 variations in sera. 



