Diagnostic preparation for the identification of beta-hemolytic streptococci

Abstract

Abstract A PREPARATION FOR THE BIOCHEMICAL IDENTIFICATION OF BHEMOLYTIC STREPTOCOCCI INTO SEROLOGIC GROUPS, E.G., GROUPS A, B, C, D, ETC., IS DISCLOSED. THIS PREPARATION COMPRISES A CARRIER, E.G., A BIBULOUS STRIP CONTAINING A GLYCEROL REAGENT BAND, A SALICIN REAGENT BAND AND AN ESCULIN REAGENT BAND. IN THE GLYCEROL AND SALICIN REAGENT BANDS THERE ARE ALSO PH INDICATOR SYSTEMS. THE ESULIN BAND CONTAINS A COMPOUND WHICH REACTS WITH ESULIN BREAKDOWN PRODUCTS TO PRODUCE A COLOR CHANGE. THESE BANDS ARE SEPARATED FROM EACH OTHER BY HYDROPHOBIC BARRIERS. IN USE, A QUANTITY OF THE BETA HEMOLYTIC STREPTOCOCCUS WHOSE SEROLOGICAL IDENTIFICATION IS TO BE DETERMINED IS TRANSFERRED ONTO EACH OF THE THREE REAGENT BANDS. A DROP OF SALINE OR WATER IS ADDED TO THE SALICIN AREA AND TO THE ESCULIN AREA. THE STRIP IS PLACED IN A TUBE CONTAINING 0.3 ML. OF SALINE OR WATER TO WET THE GLYCEROL BAND. THE REAGENT IMPREGNATED STRIP IS INCUBATED AT APPROXIMATELY 37*C. FOR TWO TO FOUR HOURS. SUGAR FERMENTATION IS MEASURED BY AN INDICATOR COLOR CHANGE AND ESCULIN HYDROLYSIS BY FORMATION OF A GREY-BLACK COLOR. GROUP A STREPTOCOCCI, WHICH CAUSE MOST OF THE CLINICAL MANIFESTATIONS SUCH AS RHEUMATIC FEVER AND NEPHRITIS, ARE ESCULIN NEGATIVE, GLYUCERIN NEGATIVE AND SALICIN POSITIVE. GROUP B AND C STREPTOCOCCI MAY BE INVOLVED IN DISEASES BUT MORE OFTEN ARE PART OF A NORMAL FLORA IN A PRIMARY ISOLATION BLOOD PLATE SHOWING B-HEMOLYSIS. IT IS IMPORTANT TO DIFFERENTIATE BETWEEN THESE GROUPS AND GROUP A. GROUP D STREPTOCOCCI, KNOWN AS ENTEROCOCCI, ARE OFTEN ASSOCIATED WITH URINARY TRACT INFECTION AND RAPID IDENTIFICATION OF THESE ORGANISMS IS ALSO CLINICALLY IMPORTANT.

Inventors

• 👤 Donald P Kronish
• 👤 Lee S Zuriff

Bibliographic Details