Dnazymes for detecting
This disclosure relates to DNAzymes and biosensors for detecting pathogenic bacteria, and in particular, for detecting Legionella pneumophila . This disclosure also provides a method for detecting the presence of Legionella pneumophila in a test sample, comprising: a) contacting said test sample with the DNAzyme or biosensor described herein, wherein the DNAzyme comprises a detectable label; b) allowing cleavage of the DNAzyme if a target is present, thereby releasing the detectable label; and c) measuring a detectable signal if the portion of the DNAzyme comprising the detectable label is released, wherein the RNA cleavage activity of the DNAzyme is activated by a target from Legionella pneumophila.
1 . A DNAzyme for detecting Legionella pneumophila comprising a sequence selected from the group consisting of SEQ ID NOS: 7-17, 21-71, 187, and 188, or a functional fragment or modified derivative thereof, wherein the functional fragment or the modified derivative comprises a first domain comprising nucleotides 3-12 of SEQ ID NO: 189 and a second domain comprising the nucleotide sequence of SEQ ID NO: 186.
2 . The DNAzyme of claim 1 , comprising a sequence selected from the group consisting of SEQ ID NOS: 7-14, 21-24, 30-36, 45, 48, 54-60, 69, 187, and 188.
3 . The DNAzyme of claim 1 , comprising the sequence of SEQ ID NO: 34 or 58.
4 . The DNAzyme of claim 1 , comprising a detectable label.
5 . The DNAzyme of claim 4 , wherein the detectable label comprises a fluorescent, a colorimetric, or other optical or electrochemical moiety.
6 . The DNAzyme of claim 5 , wherein the fluorescent moiety is a fluorophore.
7 . The DNAzyme of claim 6 , wherein the fluorophore is fluorescein.
8 . A biosensor for detecting Legionella pneumophila comprising the DNAzyme of claim 1 .
9 . The biosensor of claim 8 , further comprising a support.
10 . The biosensor of claim 9 , wherein the support comprises cellulose or paper.
11 . A kit for detecting Legionella pneumophila , wherein the kit comprises the DNAzyme of claim 1 and instructions for use of the kit.
12 . The kit of claim 11 , further comprising one or more of: i) a buffer, ii) an RNase inhibitor, and iii) a metal ion.
13 . A method for detecting the presence of Legionella pneumophila in a test sample, comprising:
a) contacting said test sample with the DNAzyme of claim 1 , wherein the DNAzyme comprises a detectable label;
b) allowing cleavage of the DNAzyme if a target is present, thereby releasing the detectable label; and
c) measuring a detectable signal if the portion of the DNAzyme comprising the detectable label is released,
wherein the RNA cleavage activity of the DNAzyme is activated by a target from Legionella pneumophila.
14 . The method of claim 13 , wherein the target is a protein target.
15 . The method of claim 14 , wherein the protein target is a protein target of 30-100 kDa.
16 . The method of claim 13 , wherein the DNAzyme detects at least 10 colony forming units of Legionella pneumophila.
17 . A method for detecting the presence of Legionella pneumophila in a test sample, comprising:
a) contacting said test sample with the biosensor of claim 8 , wherein the DNAzyme comprises a detectable label;
b) allowing cleavage of the DNAzyme if a target is present, thereby releasing the detectable label; and
c) measuring a detectable signal if the portion of the DNAzyme comprising the detectable label is released,
wherein the RNA cleavage activity of the DNAzyme is activated by a target from Legionella pneumophila.
18 . The method of claim 17 , wherein the target is a protein target.
19 . The method of claim 18 , wherein the protein target is a protein target of 30-100 kDa.
20 . The method of claim 17 , wherein the biosensor detects at least 10 colony forming units of Legionella pneumophila.