BACTERIAL ANTIGENS AND SPECIFICITY 365 



actions were encountered with the immune scrum from horses, 

 the rabbit immune serum was specific. 



H. pertussis. — While a number of types of //. pertussis have 

 been reported in the literature it appears that the types reported 

 represented serological differences between mutation forms de- 

 scribed by Shibley and Hoelscher (1934). Leslie and Gardner 

 (1931) described four dissociation phases of H. pertussis. They 

 termed them Phases I, II, III and IV. It appears that the Phase 

 I is the hemolytic smooth form that is found in whooping cough. 

 It will be recalled that Sauer's vaccine is made from hemolytic, 

 capsulated, virulent Phase I of //. pertussis. 



Brucella abortus. — There has been some controversy over the 

 nature of the specific substance in Brucella abortus. Hershey, 

 Huddleson and Pennell (1935) reported the specific reactions 

 described by others as due to a noncarbohydrate substance. In 

 later work they have found small amounts of carbohydrate in the 

 antigenic material. Libby and Joyner (1941) report isolating 

 an antigenic carbohydrate from all three strains of Brucella. 

 Cutaneous tests with this carbohydrate in infected or sensitized 

 subjects results in an immediate allergic reaction. There is no 

 delayed reaction as in the tuberculin test. 



Hemolytic Streptococci. — By means of immune sera obtained 

 from rabbits, Griffith has been able to divide hemolytic strepto- 

 cocci from scarlet fever cases into four types and a heterologous 

 group. Satisfactory typing of streptococci has not been as ade- 

 quately solved by agglutination as it has by precipitation meth- 

 ods using extracts of streptococci. Laneefield by means of the 

 precipitin reaction has confirmed and extended Griffith's work 

 on the division of hemolytic streptococci into groups and types. 

 She has described groups ''A" to "G, " the group division de- 

 pending on the occurrence of a specific carbohydrate (C) for 

 each group. Tjq^e specificity in the case of group ''A" depends 

 on the presence of an antigenic protein *'M. " In the case of the 

 other groups, type specificity rests on the presence of polysac- 

 charides designated as (S). These type specific substances are 

 present in the mucoid and Matt type colonies of group "A" and 

 in the smooth colonies of the other groups but are lacking in the 

 glossy "A" colonies and in the rough colonies of other groups. 



