Rapid detection of volatile organic compounds for identification of
View Patent ↗In various embodiments, the invention relates to a method for identifying the presence of particular bacteria in a sample. The method includes collecting a sample that includes or has been exposed to the particular bacteria and detecting, in the sample, at least one volatile organic compound indicative of the presence of the bacteria.
1. A method for identifying Mycobacterium tuberculosis bacteria in a sample, the method comprising:
detecting one or more volatile organic compounds associated with Mycobacterium tuberculosis metabolism, wherein the volatile organic compounds are indicative of at least one of a presence of, response to treatment of, and resistance of the Mycobacterium tuberculosis bacteria in the sample, the one or more volatile organic compounds being selected from the group consisting of ethyl propionate, 1-pentanol, methyl valerate, 1-hexanol, ethyl valerate, methyl caproate, ethyl caproate, and any of the foregoing compounds in isotopically labeled form;
determining the amount of the one or more volatile organic compounds; and
identifying Mycobacterium tuberculosis in the sample based on presence and concentration of one or more volatile organic compounds.
2. The method of claim 1 , wherein the one or more volatile organic compounds comprises methyl caproate.
3. The method of claim 1 , wherein the one or more volatile organic compounds comprises 1-hexanol.
4. The method of claim 1 , wherein a combination of two or more volatile organic compounds is indicative of the presence of or response to treatment or resistance of Mycobacterium tuberculosis in the sample.
5. The method of claim 1 , wherein the one or more volatile organic compounds comprises methyl caproate and 1-hexanol.
6. The method of claim 1 , further comprising collecting from a subject a sample suspected of comprising Mycobacterium tuberculosis bacteria.
7. The method of claim 1 , further comprising detecting one or more volatile organic compounds associated with Mycobacterium tuberculosis metabolism indicating at least one of a presence of, response to treatment, and resistance of the Mycobacterium tuberculosis bacteria in the sample, the one or more volatile organic compounds being selected from the group consisting of methoxybenzene (anisole), methyl 2-ethylhexanoate, a chiral version of methyl 2-ethyl hexanoate, methyl propionate, 2-pentanone, 3-pentanone, 2,4-dimethyl-1-heptene, methyl isobutyl ketone, 6-methyl-5-hepten-2-one, dimethylsulfoxide, methyl 2-methylpropionate, 1-ethoxy-2-methylpropane, 1-ethoxybutane, t-butyl ethyl ether, isobutanol, and any of the foregoing compounds in isotopically labeled form.
8. The method of claim 7 , wherein the method comprises detecting methyl caproate and methyl propionate.
9. The method of claim 1 , wherein the sample was exposed to a candidate therapy for treating Mycobacterium tuberculosis.
10. The method of claim 1 , wherein the sample comprises exhaled breath from an individual.
11. The method of claim 1 , wherein the sample is selected from the group consisting of sputum, blood, urine, pleural fluid, gastric lavage, and pleural biopsy tissue.
12. The method of claim 1 , wherein the detecting is performed using a portable device.
13. The method of claim 1 , wherein the detecting is performed using a differential mobility spectrometer.
14. A method for identifying Mycobacterium tuberculosis bacteria in a sample, the method comprising:
culturing a sample in a media comprising an alkali metal propionate, an alkali metal pentanoate, an alkali metal hexanoate, cholesterol, or any of the foregoing compounds in isotopically labeled form;
detecting one or more volatile organic compounds associated with Mycobacterium tuberculosis metabolism indicating at least one of a presence of, response to treatment of, and resistance of the Mycobacterium tuberculosis bacteria from the cultured sample, the one or more volatile organic compounds being selected from the group consisting of ethyl propionate, 1-pentanol, methyl valerate, 1-hexanol, ethyl valerate, methyl caproate, ethyl caproate, and any of the foregoing compounds in isotopically labeled form;
determining the amount of the one or more volatile organic compounds; and
identifying Mycobacterium tuberculosis in the sample based on presence and concentration of one or more volatile organic compounds.
15. The method of claim 14 , wherein the one or more volatile organic compounds comprises methyl caproate.
16. The method of claim 14 , wherein the one or more volatile organic compounds comprises 1-hexanol.
17. The method of claim 14 , wherein a combination of two or more volatile organic compounds is indicative of the presence of or response to treatment or resistance of Mycobacterium tuberculosis from the cultured sample.
18. The method of claim 14 , wherein the sample is selected from the group consisting of sputum, blood, urine, pleural fluid, gastric lavage, and pleural biopsy tissue.
19. The method of claim 14 , wherein the sample is sputum.
20. The method of claim 14 , further comprising extracting the one or more volatile organic compounds from the culture by solid phase microextraction from a headspace of the culture or thermal desorption from a headspace of the culture to provide a more concentrated sample of the one or more volatile organic compounds for detection.
21. The method of claim 14 , further comprising, prior to culturing the sample, collecting the sample from a subject.