

AGGLUTININS 225 



Antitoxic serums are strictly specific. Under the head of each of the 

 pathogenic micro-organisms the antitoxic properties of the corresponding 

 serum will be considered in detail. 



SECTION III. AGGLUTININS. 



Durham and Gruber when studying antityphoid serum demonstrated a 

 very remarkable property of the serum. If a small quantity of serum from 

 a typhoid-immunized animal be added to a broth culture of the typhoid 

 bacillus the bacilli distributed through the medium lose their motility, collect 

 together and become agglutinated into masses, retaining however their 

 vitality. This phenomenon is known as agglutination and the serum is said 

 to possess agglutinating properties. 



Previously to Durham and Gruber's experiments, Bordet had demonstrated 

 a similar action of anticholera serum on cholera vibrios, and it has since 

 been shown that in the majority of cases the serum of an animal immunized 

 against a micro-organism agglutinates the organism used for immunization 

 (cholera, dysentery, tuberculosis, mediterranean fever, plague, glanders, etc.). 



The property of agglutination however is not limited to the serum of 

 immunized animals. [A. S. Griinbaum showed that] it appears quite early, 

 before a state of immunity has been created, as soon as the tissues have 

 been invaded by a pathogenic organism. The reaction of agglutination is a 

 reaction of infection. It remains, moreover, for a long time after recovery 

 has taken place, being found as has already been stated in a marked degree 

 in the serum of immunized individuals. 



The agglutination reaction is specific : the serum of an enteric patient 

 agglutinates the typhoid bacillus and (with certain reservations) the typhoid 

 bacillus only. The serum of cholera patients similarly agglutinates only the 

 cholera vibrio. 



[A. S. Griinbaum and shortly afterwards] Widal showed that practical use 

 can be made of these facts in the diagnosis of infective diseases and to [the 

 former] is due the method of serum diagnosis. Take, for example, the case 

 of a person thought to be suffering from enteric fever : it is only necessary 

 to mix a few drops of his serum with a culture of the typhoid bacillus : 

 then if the patient be suffering from enteric fever the bacilli will be 

 agglutinated ; on the other hand, if he be suffering from some disease other 

 than enteric fever the bacilli will remain separate and motile. 



Conversely, suppose it is required to determine whether a bacillus is the 

 typhoid bacillus or not : in this case it is sufficient to prepare a culture of 

 the unknown bacillus and to mix it [in due proportion] with a typhoid - 

 agglutinating serum : if agglutination take place the bacillus may without 

 hesitation be affirmed to be the typhoid bacillus. 



To obtain reliable results, there are certain precautions which must be 

 strictly observed in carrying out the reaction. To exemplify : most normal 

 serums and especially human serums when used in large quantities 

 agglutinate a considerable number of organisms : if a mixture of serum and 

 organisms be made without knowing the proportions in which they are mixed 

 agglutination might be obtained apart from any specific relation of the 

 ingredients to each other. The following rules should therefore always be 

 followed : 



(i) The serum under investigation must be diluted [Grunbaum] and the 

 dilution carried to such a degree that the minimal dose of serum required for 

 lutination is determined. For purposes of comparison the minimum 



p 



