Medium for the specific detection of resistant microorganisms

Abstract

A method for distinguishing among a first group of microorganisms, belonging to a first taxon of yeasts that is resistant to an antifungal; a second group of microorganisms, belonging to a second taxon of yeasts that is different than the first taxon of yeasts, and that exhibits the mechanism of resistance to the antifungal exhibited by the first group; and a third group that is not resistant to the antifungal.

1 . A method for distinguishing among at least three groups of microorganisms that may be present in a biological sample, the at least three groups comprising:
 a first group of microorganisms, belonging to a first taxon of yeasts that is resistant to an antifungal;   a second group of microorganisms, belonging to a second taxon of yeasts that is different than said first taxon of yeasts, and that exhibits the mechanism of resistance to the antifungal exhibited by the first group; and   a third group that is not resistant to said antifungal;   
       the method comprising:
 inoculating a culture medium with the biological sample, wherein the culture medium comprises:
 a first substrate for detecting a first enzymatic or metabolic activity of said first group of microorganisms; 
 a marker for differentiating the first group of microorganisms and the second group of microorganisms, said marker being a substrate for detecting an enzymatic or metabolic activity of said second group of microorganisms; and 
 the antifungal; and 
 
 distinguishing among any members of the three groups of microorganisms that are present on the culture medium to determine of which group of microorganisms they are members on the basis of their interactions with the first substrate, the marker, and the antifungal. 
 
     
     
         2 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to amphotericin B;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. lusitaniae , and  C. kefyr  resistant to amphotericin B; and   the third group of microorganisms is yeasts not resistant to amphotericin B.   
     
     
         3 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to amphotericin B;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. glabrata , and  C. krusei  resistant to amphotericin B; and   the third group of microorganisms is yeasts not resistant to amphotericin B.   
     
     
         4 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to fluconazole;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. lusitaniae , and  C. kefyr  resistant to fluconazole; and   the third group of microorganisms is yeasts not resistant to fluconazole.   
     
     
         5 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to fluconazole;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. glabrata , and  C. krusei  resistant to fluconazole; and   the third group of microorganisms is yeasts not resistant to fluconazole.   
     
     
         6 . The method of  claim 1 , wherein:
 the first substrate is a substrate for detecting a hexosaminidase enzymatic activity,   the marker is a second substrate for detecting a beta-glucosidase activity, and   the antifungal is amphotericin B.   
     
     
         7 . The method of  claim 1 , wherein:
 the first substrate is a substrate for detecting a hexosaminidase enzymatic activity,   the marker is a second substrate for detecting a phosphatase activity, and   the antifungal is amphotericin B.   
     
     
         8 . The method of  claim 1 , wherein:
 the first substrate is a substrate for detecting a hexosaminidase enzymatic activity;   the marker is a second substrate for detecting a beta-glucosidase activity; and   the antifungal is fluconazole.   
     
     
         9 . The method of  claim 1 , wherein:
 the first substrate is a substrate for detecting a hexosaminidase enzymatic activity;   the marker is a second substrate for detecting a phosphatase activity; and   the antifungal is fluconazole.   
     
     
         10 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to amphotericin B;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. lusitaniae , and  C. kefyr  resistant to amphotericin B;   the third group of microorganisms is yeasts not resistant to amphotericin B;   the first substrate is a substrate for detecting a hexosaminidase enzymatic activity;   the marker is a second substrate for detecting a beta-glucosidase activity; and   the antifungal is amphotericin B.   
     
     
         11 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to amphotericin B;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. glabrata , and  C. krusei  resistant to amphotericin B;   the third group of microorganisms is yeasts not resistant to amphotericin B;
 the first substrate is a substrate for detecting a hexosaminidase enzymatic activity; 
   the marker is a second substrate for detecting a phosphatase activity; and   the antifungal is amphotericin B.   
     
     
         12 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to fluconazole;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C. lusitaniae , and  kefyr  resistant to fluconazole;   the third group of microorganisms is yeasts not resistant to fluconazole;   the first substrate is a substrate for detecting a hexosaminidase enzymatic activity;   the marker is a second substrate for detecting a beta-glucosidase activity; and   the antifungal is fluconazole.   
     
     
         13 . The method of  claim 1 , wherein:
 the first group of microorganisms is yeasts comprising  Candida albicans  resistant to fluconazole;   the second group of microorganisms is yeasts comprising at least one of  Candida tropicalis, C glabrata , and  C. krusei  resistant to fluconazole;   the third group of microorganisms is yeasts not resistant to fluconazole;   the first substrate is a substrate for detecting a hexosaminidase enzymatic activity;   the marker is a second substrate for detecting a phosphatase activity; and   the antifungal is fluconazole.