The origin of some of the streptococci found in milk / by L.A. Rogers and Arnold O. Dahlberg.

  • Lore Alford Rogers
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: The origin of some of the streptococci found in milk / by L.A. Rogers and Arnold O. Dahlberg. Source: Wellcome Collection.

    13/28 page 501
    eas ree ees a LS ees a ee ee eee lg TaBLEe II.—Physiological characters of all cultures—Continued. Chains. Percentage of normal acid. i. duction. Milk curd. Morphology. Liquefied gelatin. Neutral red re- Culture No. © Dextrose. Adonite Saccha- rose. Lactose.- Raffinose Starch Inulin Mannite 2 hae . H HD OF H ° ° ° 000000000, Oho: 2 ele) ww rm HO CO .90nv0000NPrNO0, 00 69 ° bHWN baowo .-co00c00od0, HAH ND EBUNNH HD HWHHD HD H fe) ,0000000, ° Sllgeistl delice t Mesure eg oe sal aa: FHEFFEFEFEEFEFEEFHFS | PPSSESEEOHREQHED OOM AWAOVOMNATW ANWUNY OOF OTOA: 1020 Haas WNHkWNHWHH NH H OONRD ADDN AHAB CO ° S 2 Les] Lal co BOBO DE mOOn sah POKTHE AALS HOUUBEHEURD HNYNHPN MOOAUATOORWW WOU NKOD Ww Qbpbapappedunaasoun. , bePPedeupaaouudauagga OH MWOMOmMDAWO M3 FHOO ANUNWWHuUDR ooo0oo00o0090 In one particular our results do not agree with the conclusions reached .by Stowell, Hilliard, and Schlesinger ' and by Howe and others in that the “metabolic gradient’? which they establish, in our opinion, can be correct only for the particular group under consideration, since the number of cultures utilizing any particular carbohydrates or similar compound is dependent on the peculiarities of the cultures as well as on the composition or the configuration of the test substance. While in a general way our cultures follow the scheme outlined by Stowell, Hilliard, and Schlesinger, this arrangement may be varied, as will be pointed out later, by varying the source from which the cultures are obtained. In one group of our collection a much larger percentage of cultures give a fermentation with mannite than with raffinose; in others the conditions are reversed. In no case did we obtain a higher per- centage of positive results with mannite than with inulin, although both Winslow and Stowell, Hilliard, and Schlesinger put inulin above mannite. Dulcite may be considered as one of the more difficultly fermented alcohols, and yet in our work on the colon group we found that dulcite was fermented most frequently, not by the more active group but by the one which otherwise showed weak fermentative ability. With adonite the conditions were reversed. There is among all acid-forming bacteria and especially among the streptococci considerable variation in the maximum amount of acid produced. Winslow has shown that this may be a valuable aid in dis- 1Stowell, E. C., Hilliard, C. M., and Schlesinger, M. J. A statistical study of the streptococci from milk and from the throat. Jour. Infect. Diseases, v. 12, no. 2, DP. 144-164. 1913.
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