924 ANTIBACTERIAL SERA 



"Anthrax bacilli are also able to produce an aggressin or toxic substance exerting 

 negative chemotaxis; a part of the action of anti-anthrax serum is the neutralization 

 of these substances, which thereby facilitates phagocytosis."^ The presence of pro- 

 tective antibodies in the serum can be demonstrated by animal experiment. 



Much statistical data has accumulated attesting the therapeutic value of anti- 

 anthrax serum, but as yet no satisfactory method of standardization has been worked 

 out. The Health Committee of the League of Nations, at its 1924 session, suggested 

 that the time had come for a more thorough investigation of the methods of titration 

 and standardization of the serum, in order to overcome some of the uncertainties now 

 existing on these points. 



ANTI-DYSENTERIC SERUM 



The two principal types of dysentery bacilli are differentiated by their toxin-pro- 

 ducing properties. The Shiga-Kruse group, which appears to be the principal causa- 

 tive factor in tropical countries, produces a soluble exotoxin having a pronounced 

 neurotoxic effect. The second group includes strains (paradysentery) which produce 

 no soluble exotoxin. These are the so-called Flexner and Hiss types, which are 

 principally responsible for the dysentery in this country. Anti-dysenteric serum pre- 

 pared for the Flexner type is an antibacterial serum and is without effect in the treat- 

 ment of the Shiga-Kruse infection. It has proved of little value in the treatment of 

 Flexner-Hiss infections. It is not logical to believe that the introduction into the 

 bloodstream of antibodies directed against the organisms themselves would have any 

 effect on this disease, since the causative organisms are confined to the intestine. 



The anti-dysenteric sera supplied commercially are usually polyvalent sera pre- 

 pared by immunizing horses against the various types of dysentery bacilli, including 

 those of Shiga, Kruse, Flexner, and Hiss. They therefore contain both antibacterial 

 and antitoxic immune bodies. Since the therapeutic value depends principally on 

 the antitoxin content, they have been found of most value in European and Asiatic 

 countries where Shiga-Kruse infections are most common. 



Preparation. — Animals must be immunized with great care, owing to the toxic property 

 of the organisms. It is well, for the first few doses, to treat the centrifuged organisms with 

 a weak solution of sodium hydroxide before injection. Afterward, periodic injections of whole 

 culture may be employed, but the condition of the animal must be watched constantly. 



Standardization is done by means of agglutination tests which must conform to the 

 methods and standards required by the Hygienic Laboratory of the Public Health Service. 

 Standardization by means of a toxin-antitoxin reaction has been tried, and it has been found 

 that a good serum in amounts of i cc. will protect rabbits against 10 ML.D. of the toxic 

 material. 



We have used the following procedure in the preparation of toxic material for this test. 

 The bacilli were grown on neutral plain agar for several generations, and finally in Blake 

 bottles on the same media. The growth was washed off in salt solution, centrifuged, 

 washed rapidly with alcohol and ether, and then placed in a desiccating jar and dried rapidly. 

 A weighed quantity of the dried material was mixed with sterile sand and ground in a mortar 

 with a measured amount of salt solution. The resulting mass was centrifugated several times, 

 and the opalescent supernatant was employed for injection purposes. Doses of 0.1-0.2 cc. 

 injected intravenously in a rabbit resulted, within two or three days, in a progressive paralysis 



' Kolmer, J. A.: Infection, Immunity and Biologic Therapy (3d ed.). 1924. 



