122 PHARMACEUTICAL BACTERIOLOGY. 



the protoplasm molecule; second, the overproduction and liberation of these 

 receptors following this binding; and third, the union of these free receptors 

 or antibodies with free toxin haptophore groups before these can reach the 

 cell to injure them by the action of their toxophore groups. The antigens 

 that are known with their respective antibodies as given by Hektoen are: 



Antigens. Products of Immunization. 



Toxins Antitoxins . 



Ferments Antiferments 



Precipitinogens Precipitins 



Agglutinogens Agglutinins 



Opsonogens Opsonins 



Lysogens Amboceptors or lysins 



Antitoxins Antianti toxins 



Agglutinins Antiagglutinins 



Complements Anticomplements 



Opsonins Antiopsonins 



Amboceptors . Antiamboceptors 



Precipitins Antiprecipitins 



These antibodies all result from the overproduction of simple receptors, 

 but the protoplasm of cells may form still other cell receptors which are much 

 more complicated and subserve the absorption of more complicated and 

 complex albuminous molecules than those of toxins. 



Bacterial clumping or agglutinating phenomena are extremely interesting 

 as well as valuable in the diagnosis of disease. Upon this behavior of 

 bacteria depends the Widal typhoid fever test. If the serum of an animal 

 inoculated with the typhoid bacillus (antiserum) is added to a liquid culture 

 or suspension of typhoid bacilli, the latter cease to move and after a time 

 become aggregated into irregular clumps or masses. The same phenomenon 

 is observed if instead of blood of a typhoid injected animal, the blood of a 

 typhoid fever patient is employed. The reaction is quite specific, though 

 not absolutely so. That is, similar agglutinating phenomena are produced 

 by related bacilli, as the typhoid bacillus, the para-typhoid bacillus and the 

 colon bacillus. Many other bacteria, beside the colon-typhoid group, are 

 agglutinated by their respective antisera. In addition to diagnosing disease 

 as in typhoid fever (the Widal test gives results even before there are marked 

 disease symptoms), the agglutinating phenomena are useful in the identifica- 

 tion of bacteria. The technic while not difficult, calls for many pre- 

 cautionary measures and requires considerable time and care to avoid 

 erroneous conclusions. 



In 1897 Kraus found that when the germ-free filtrates from broth cultures 

 of bacteria were mixed with their respective antisera (serum from animals 

 inoculated with the specific bacteria) the formation of a white precipitate 

 occurred. The substance in the immunized serum which causes the forma- 



