M. LEVINE 



pair of characters is given in table 2 1 which shows rhamnose correlates best 

 with the other characters. Subdividing on rhamnose, two groups are obtained 

 as follows : 



Rhamnose + 

 Rhamnose 



Strains 

 10 



Sucrose 

 80 

 60 



-Percent Positive 



Dextrin 

 70 



Raffinose 







94 



Indol 

 100 



TABLE 2 

 CORRELATION COEFFICIENTS FOR FERMENTATIVE CHARACTERS 



Raffinose fermentation is particularly interesting. Of 30 strains in the 

 rhamnose-negative subgroup which fermented sucrose, all attacked raffinose ; 

 but, of 8 sucrose fermenters in the rhamnose-positive subgroup none attacked 

 the trisaccharid. The source of the 10 rhamnose fermenting strains was: 

 Strain 26 was isolated at the Cent. Med. Dept. Lab. from a patient and diag- 

 nosed as probably B. dys. Y; (60 and 61) were isolated at Lab. 1, A. E. R, 

 from a patient and carrier, respectively, and reported as B. dys. Flexner and 

 B. dys. Y. and sent in for further identification. As the foregoing diagnoses 

 were based merely on the two serums available Flexner and Y the designa- 

 tions should not be accepted as final. It would be desirable to know to which 

 race of Flexner bacilli they belong. The remaining 7 strains were received 

 from Dr. Andrews and Dr. Inman of London. One, 94, was labelled B. 

 flexneri Y race which is a sort of composite of the V, W, X and Z races. 

 The other 6 strains were all B. flexneri Z race. Thus there seems to be a 

 correlation between rhamnose fermentation and the Z race of B. flexneri. 

 If subdivision is to be made at all on fermentation reactions, then it appears 

 that rhamnose would be the logical choice. 



ACID PRODUCTION FROM GLUCOSE 



In order to devise a medium for the differentiation of B. alkalescens and 

 B. dispar from the other dysentery or dysentery-like strains, the effects of 

 various constituents of a selected medium on the rate of acid production and 

 reversion were studied. Ten cultures, 2 B. dys. Shiga, 2 B. dys. Y, 2 B. dys. 

 Flexner, 2 B. alkalescens, and 2 B. dispar were chosen for study. 



Concentration of glucose. The medium consisted merely of peptone (Difco) 

 1% dipotassium phosphate 0.4%, and glucose in varying amounts 0.0 to 0.5%, 

 prepared in the following manner: To 1,000 cc of distilled water in a flask 

 was added 10 gm. of peptone, 4 gm. of dipotassium phosphate, and the flask 

 was then heated until the contents were dissolved (about 20-30 minutes). 

 The medium was then filtered through paper and enough of a freshly pre- 

 pared 10% glucose solution was added to give the desired concentration of 

 the carbohydrate. The medium was tubed (about 20-25 c c) and sterilized in 

 the autoclave 10 minutes at 10 pounds, after which it was incubated to elim- 

 inate unsterile tubes. 



1 See Levine, Jour. Infect. Dis., 1918, 3, p. 253. 



