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The Fermentation of Glucosides by Bacteria of the Typhoid-coli 

 Group and the Acquisition of New Fermenting Powers by 

 Bacillus dysenterise and other Micro-organisms. Prelimi- 

 nary Communication. 



By F. W. Twort, M.K.C.S., L.K.C.P. 



(Communicated by Leonard Hill, M.B., F.R.S. Received March 7, — 

 Read April 18, 1907.) 



(From the Bacteriological Laboratory, London Hospital, E.) 



For a number of years bacteriologists have largely relied upon certain 

 fermentation reactions of sugars and alcohols for the differentiation of 

 various micro-organisms which may otherwise be almost indistinguishable. 

 This applies more especially to the case of bacteria occurring in the so-called 

 " typhoid-coli group," although recently this method of differentiation has 

 also been extended by Mervyn Gordon (1), Andrewes, Horder(2), and others, 

 to the group of micro-organisms described under the general name of 

 Streptococcus. As fresh fermentible substances have been introduced as 

 tests, the number of different species occurring in such micro-organismal 

 groups has become very large. Mervyn Gordon, in his studies on Strepto- 

 coccus and Staphylococcus, introduced tests on certain sugars and upon such 

 glucosides as coniferin and salicin, and he considered that these reactions 

 were of help in differentiating different Streptococci from each other. 

 MacConkey (3) has also published extended observations on the capability of 

 certain lactose fermenting fsecal bacteria to attack sugars like saccharose and 

 dulcite, and from the reactions obtained he was led to subdivide these 

 lactose fermenters into four groups as follows : — 



(1) A group represented by Bacillus acidi lactici, Hueppe, capable of 



fermenting lactose, but without action on dulcite or saccharose. 



(2) A group, the typical representative of which is Bacterium coli, 



Escherich. In this case lactose and dulcite are fermented, but not 

 saccharose. 



(3) A group of the types Bacillus neapolitanus, Emmerich, and Bacillus 



pneumoniae, Friedlander, containing organisms which ferment 

 lactose, saccharose, and dulcite. 



(4) A group containing micro-organisms capable of fermenting lactose 



and saccharose, but not dulcite. In this group were placed 

 Bacillus lactis aerogenes, Escherich, Bacilhis capsulatus, Pfeiffer, 

 and Bacillus cloacae, Jordan. 



