THE GROUP OF THE DY^ENTEliY BACILLI :')o9 
of these animals contain specific agjjlutinins, lysins, precipitins and 
opsonins, frequently of high potency. The agglutinins and other 
immune bodies are quite specific for the Shiga type; the Flexner-IIiss- 
Russell group is quite heterogeneous with respect to the production of 
agglutinins. Apparently the raannitol fermenting group comprises 
quite a series of closely related, but serologically distinguishable 
trains or types.' According to Todd, and Kraus and Doerr- specific 
antitoxins are also demonstrable in the sera of these animals, par- 
ticularly in animals immunized to the Shiga bacillus. The agglutinins 
which are specific for the type of organism used in immunization are, 
according to Dopter,^ as a rule of greater potency when killed cul- 
tures exclusively are used for immunizing. In thoroughly immunized 
animals the agglutinins may be active even in dilutions of 1 to 5000. 
Specific bacteriolysins have been demonstrated in immune sera 
in vitro by Shiga^ and in vivo by Kruse.^ Specific precipitins, which 
in dilutions of 1 to 10 or greater will produce a precipitate in broth 
filtrates of the homologous strain, but not, as a rule, for other types 
of the dysentery bacilli are also found. The sera of patients who 
have recovered from attacks of bacillary dysentery usually contain 
specific agglutinins which are active even in dilutions of 1 to 50. 
Specific precipitins, lysins and opsonins are also demonstrable in the 
sera of these patients. 
T }} era py.— Attempts to immunize man with vaccines, both mono- 
and polyvalent,"^ sensitized vaccines (bacteria which have been in 
contact with antidysentery serum, then centrifugalized, washed, and 
suspended in salt solution, according to the method of Besredka and 
of Gay), and the use of antisera, usually derived from immunized 
horses, have not been generally successful, although a few favorable 
results have been recorded. The vaccines, particularly the Shiga 
vaccine, are very toxic. 
Bacteriological Diagnosis. — (a) Agglutinin Reaction.— The sera of 
normal individuals rarely agglutinate dysentery bacilli in dilutions 
greater than 1 to 10, although Dopter'' states that the Flexner organ- 
ism may be clumped with the serum of apparently normal individuals 
in a dilution greater than 1 to 10. For this reason agglutination tests 
should be made in a dilution of 1 to 20 to 1 to 30 with the Shiga organ- 
ism, and 1 to 80 to 1 to 100 with the Flexner strain in each case ex- 
amined, since one or the other organism, or both, may be present in 
typical cases of bacillary dysentery. Agglutinins do not, as a rule, 
appear in mild cases, and in severe cases they are not demonstrable 
until from the seventh to the tenth day on the average. 
The serum of dysentery carriers, both those giving a history of a 
previous attack and those with the negative dysentery history, fre- 
' See Medical Research Committee Report No. 42, 1919. 
- Loc. cit. 5 Loc. cit., p. 84. 
^ Loc. cit. s Deutsch. med. Wchnschr., 1903, 29, 6. 
6 Shiga: Deutsch. med. Wchnschr.. 1901, 27, 741, 783. Kruse: Ibid., 1903, 29, 6, 49. 
' Loc. cit., p. 91. 
