Types of Specific Carbohydrates in the Cholera and Cholera-Like Vibrios. ∗

Abstract

We reported the finding of 2 types of specific carbohydrate in the vibrios. 1 Both types contained an aldobionic acid from which on prolonged hydrolysis galactose and glucuronic acid could be isolated. The first type, which has been found only in vibrios isolated from cholera, also contained a second sugar, which proved to be galactose. The second type of specific carbohydrate, which occurred in a few of the vibrios from cholera and in all of the nonagglutinating water vibrios, had arabinose in place of the galactose of the first type. Both galactose and arabinose were found to be readily separable from the specific substance by mild hydrolysis. The structure and constituents of these carbohydrates have been more extensively considered in other publications. 2

As an example of the second type of carbohydrate and of the results of its analysis we may outline the study of vibrio W880, which was isolated from water in an endemic cholera area (Calcutta), and is a smooth, non-agglutinating organism. Three and one-half grams of the purified specific polysaccharide was added to 5.0 cc. of 50% H₂SO₄ and the mixture placed at 37° for 20 hours. Reducing substances, 18%, calculated as glucose. The sulphuric acid was removed from the hydrolysate by CaCO₃, and the calcium salt of the aldobionic acid prepared and precipitated out by the addition of alcohol. The supernatant fluid was concentrated and a phenylosazone prepared from it which had a melting point of 158° to 160°. On the basis of our previous experience with the vibrio carbohydrates, we were able to take this result as an indication of the presence of arabinose. 2

The decomposed calcium salt was found to have a reducing power equivalent to 80 mg. of glucose.