Methods and compositions for the detection of beta-lactamases

Abstract

Presented herein are methods and compositions for the detection of specific beta-lactamases, including class A serine carbapenemases, metallo-beta-lactamases, AmpC beta-lactamases, and extended-spectrum beta-lactamases (ESBLs). The methods presented herein include methods that permit the detection of the presence of specific beta-lactamases in bacterial samples within as few as 2 to 10 minutes.

1 . A method for detecting the presence of a beta-lactamase, comprising:
 (a) contacting:
 i. a first bacterial sample with a first composition comprising a detectable beta-lactamase substrate and an AmpC inhibitor, and 
 ii. a second bacterial sample with a second composition comprising a detectable beta-lactamase substrate, an AmpC inhibitor, and a serine beta-lactamase inhibitor in an amount sufficient to inhibit an extended-spectrum beta-lactamase (ESBL) and an original-spectrum beta-lactamase (OSBL) but not a class A serine carbapenemase, wherein the first and second bacterial samples are from the same source; and 
   (b) detecting utilization of the substrate in the first composition and the second composition, such that a beta-lactamase is detected if the substrate has been utilized in the first and second compositions, wherein the beta-lactamase is a class A serine carbapenemase or a metallo-beta-lactamase.   
     
     
         2 - 28 . (canceled) 
     
     
         29 . A kit for detecting the presence of a beta-lactamase, comprising, in one or more containers:
 (a) a first composition comprising a detectable beta-lactamase substrate and an AmpC inhibitor; and   (b) a second composition comprising a detectable beta-lactamase substrate,   an AmpC inhibitor, and a serine beta-lactamase inhibitor in an amount sufficient to inhibit an ESBL and an OSBL but not a class A serine carbapenemase.   
     
     
         30 - 48 . (canceled)