Method for detecting escherichia coli
Described herein are methods of detecting an infection and for detecting the presence or absence of microorganisms, for example, wound pathogens in a sample, by contacting a sample with an enzyme produced and/or secreted by the bacteria, and detecting modification or the absence of modification of the substrate, as an indicator of the presence or absence of the enzyme in the sample. The present invention also features a biosensor for detecting the presence or absence of bacteria in a sample.
1 . A method for detecting the presence or absence of Escherichia coli in a sample, comprising the steps of:
a) contacting the sample with a detectably labeled substrate for an enzyme produced and/or secreted by Escherichia coli , under conditions that result in modification of said substrate by said enzyme; and
b) detecting the modification or the absence of the modification of said substrate,
wherein modification of said substrate indicates the presence of Escherichia coli in said sample, and wherein the absence of modification of said substrate indicates the absence of Escherichia coli in said sample.
2 . The method of claim 1 , wherein said enzyme is a protease.
3 . The method of claim 1 , wherein said sample is selected from the group consisting of a wound surface on a subject and a body fluid.
4 . The method of claim 1 , wherein said substrate is on a solid support.
5 . The method of claim 4 , wherein said solid support comprises a material required to be free of microbial contaminants.
6 . The method of claim 4 , wherein said solid support is a selected from the group consisting of a wound dressing, a container for holding body fluids, a disk, a scope, a filter, a lens, foam, cloth, paper, a suture, a food packaging material, and a swab.
7 . The method of claim 6 , wherein said container for holding body fluids is selected from the group consisting of a urine collection bag, a blood collection bag, a plasma collection bag, a test tube, a catheter, and a well of a microplate.
8 . A method for detecting the presence or absence of an infection in a subject, comprising the steps of:
a) contacting a sample obtained from a subject with a detectably labeled substrate for an enzyme produced and/or secreted by Escherichia coli , under conditions that result in modification of said substrate by said enzyme; and
b) detecting the modification or the absence of the modification of said substrate,
wherein modification of said substrate indicates the presence of an infection in said subject, and wherein the absence of modification of said substrate indicates the absence of an infection in said subject.
9 . The method of claim 8 , wherein said enzyme is a protease.
10 . The method of claim 8 , wherein said sample is a body fluid.
11 . The method of claim 8 , wherein said substrate is on a solid support.
12 . The method of claim 11 , wherein said solid support comprises a material required to be free of microbial contaminants.
13 . The method of claim 12 , wherein said solid support is a selected from the group consisting of a wound dressing, a container for holding body fluids, a disk, a scope, a filter, a lens, foam, cloth, paper, a suture, and a swab.
14 . The method of claim 13 , wherein said container for holding body fluids is selected from the group consisting of a urine collection bag, a blood collection bag, a plasma collection bag, a test tube, a catheter, and a well of a microplate.
15 . A method for detecting the presence or absence of a wound infection in a subject, comprising the steps of:
a) contacting a wound in a subject with a detectably labeled substrate for an enzyme produced and/or secreted by Escherichia coli , under conditions that result in modification of said substrate by said enzyme; and
b) detecting the modification or the absence of the modification of said substrate,
wherein modification of said substrate indicates the presence of a wound infection in said subject, and wherein the absence of modification of said substrate indicates the absence of a wound infection in said subject.
16 . The method of claim 15 , wherein said enzyme is a protease.
17 . The method of claim 15 , wherein said substrate is on a solid support.
18 . The method of claim 17 , wherein said solid support is a wound dressing.
19 . A biosensor for detecting the presence or absence of Escherichia coli in a sample, said biosensor comprising a solid support and a detectably labeled substrate specific for an enzyme produced and/or secreted by said microorganism, said substrate attached to said solid support.
20 . The biosensor of claim 19 , wherein the solid support comprises a material required to be free of microbial contaminants.
21 . The biosensor of claim 19 , wherein said solid support is a selected from the group consisting of a wound dressing, a container for holding body fluids, a disk, a scope, a filter, a lens, foam, cloth, paper, a suture, a food packaging material, and a swab.
22 . The biosensor of claim 21 , wherein said container for holding body fluids is selected from the group consisting of a urine collection bag, a blood collection bag, a plasma collection bag, a test tube, a catheter, and a well of a microplate.
23 . The biosensor of claim 19 , wherein said biosensor directly contacts said wound.
24 . A kit for detecting an infection, comprising a biosensor according to claim 19 , and one or more reagents for detecting the enzyme produced and/or secreted by Escherichia coli causing said infection.