THE DETECTION OF BACTERIAL PATHOGENICITY 245 



antigen will provide a more rapid method. Perhaps the leading example 

 is that described by Larson et al. (1951) in which the tissue of plague- 

 infected rodents is extracted and the extract used as precipitin or comple- 

 ment-fixing antigen. Another, and older, example is the so-called 

 thermal precipitin or Ascoli test for anthrax. In heavily infected animals 

 pneumococcal polysaccharide has been extracted from visceral tissues 

 and the extract used as antigen with antipneumococcal rabbit serum. 



CONCLUSION 



In the foregoing sections no attempt has been made to provide the 

 reader with an exhaustive description of the various techniques and 

 reactions required in the determination of bacterial pathogenicity. Each 

 organism requires special conditions, and the available bacteriologic 

 literature contains numerous and excellent descriptions of the specific 

 diagnostic requirements in pathogenicity of each microorganism. For 

 purposes of a brief summary Table 26 has been prepared to provide an 

 over-all view of the bacteriologic tests used for the more common patho- 

 gens. In almost every instance it is necessary to supplement the animal 

 tests with cultural or serological procedures as well. It is obvious that 

 good techniques and skill in their application are not enough to interpret 

 the results of animal inoculation intelligently. The operator must at all 

 times be aware of the pitfalls of these procedures and should have a good 

 background in pathogenic bacteriology. 



REFERENCES 



Dubos, R. J. 1948. "Bacterial and Mycotic Infections of Man." J. B. Lippincott 



Company, Philadelphia. 

 Haudauroy, P. 1948. "Traite de bacteriologie," Masson et Cie, Paris. 

 Larson, C. L., C. B. Philip, W. C. Wright, and L. E. Hughes. 1951. /. Immunol, 



66, 249. 

 Topley, W. W. C, and G. S. Wilson. 1946. "Principles of Bacteriology and 



Immunity," 3d ed. The Williams & Wilkins Company, Baltimore. 



