Method of diagnosing pneumonia by detecting a volatile organic compound

1. A method of diagnosing an existing or developing acute pneumonia induced by a microorganism comprising:

a) obtaining a respiratory air sample from a subject,

b) detecting one or more volatile organic compound(s) in the respiratory air sample without culturing the respiratory air sample prior to the detecting, wherein the volatile organic compound is selected from the group consisting of 2-ethylacrolein, 2-methyl-2-butenal (Z), ethyl formate, ethyl isovalerate, isopentyl acetate, hydroxyacetone, 2-butanol, 2-methylbutyl 2-methylbutyrate, 2-methylbutyl isobutyrate, amyl isovalerate, ethyl 2-methylbutyrate, isoamyl butyrate, methyl 2-methylbutyrate, 1,10-undecadiene, 10-methyl-1-undecene, 1-decene, 1-nonene, 1-vinyl aziridine, mercaptoacetone, 3-phenylfuran, 3-(methylthio)propanal, o-hydroxybenzaldehyde, methyl propionate, vinyl butyrate, 2-acetyl-1,4,5,6-tetrahydropyridine, S-methyl thioacetate, 3-methyl-1-butanol, 3-(ethylthio)-propanal, 1-butanol, dimethyltrisulfide (DMTS), methyl methacrylate, and

c) administering an effective amount of an antibiotic to the subject when the one or more volatile organic compound(s) in the sample are detected in the respiratory air sample.

2. The method of claim 1 , wherein existing or developing acute pneumonia is hospital acquired pneumonia.

3. The method of claim 1 , wherein the microorganism is Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae or Haemophilis influenza.

4. The method of claim 3 , wherein:

a) one or more volatile organic compound(s) selected from the group consisting of 2-methyl-1-propanol, 2-ethylacrolein, 2-methyl-2-butenal (Z), ethyl formate, ethyl isovalerate, isopentyl acetate and hydroxyacetone is indicative of the presence of Staphylococcus aureus ; and/or

b) one or more volatile organic compound(s) selected from the group consisting of 2-butanol, 2-methylbutyl 2-methylbutyrate, 2-methylbutyl isobutyrate, amyl isovalerate, ethyl 2-methylbutyrate, isoamyl butyrate, methyl 2-methylbutyrate, 1,10-undecadiene, 10-methyl-1-undecene, 1-decene, 1-nonene, 1-vinyl aziridine, 2-methoxy-5-methylthiophene and mercaptoacetone is indicative of the presence of Pseudomonas aeruginosa ; and/or

c) one or more volatile organic compound(s) selected from the group consisting of 3-phenylfuran and 3-(methylthio)propanal is indicative of the presence of Streptococcus pneumonia ; and/or

d) one or more volatile organic compound(s) selected from the group consisting of o-hydroxybenzaldehyde, methyl propionate, vinyl butyrate, 2-acetyl-1,4,5,6-tetrahydropyridine and S-methyl thioacetate is indicative of the presence of Haemophilus influenza; and/or

e) the volatile organic compound 3-methyl-1-butanol is indicative of the presence of Staphylococcus aureus and/or Pseudomonas aeruginosa ; and/or

f) the volatile organic compound 2-nonanone is indicative of the presence of Pseudomonas aeruginosa (B) and/or Streptococcus pneumonia ; and/or

g) the volatile organic compound 3-(ethylthio)-propanal is indicative of the presence of Pseudomonas aeruginosa and/or Haemophilus influenza; and/or

h) the volatile organic compound 1-butanol is indicative of the presence of Staphylococcus aureus, Streptococcus pneumoniae and/or Haemophilus influenzae ; and/or

i) the volatile organic compound DMTS is indicative of the presence of Pseudomonas aeruginosa, Streptococcus pneumoniae and/or Haemophilus influenzae.

5. The method of claim 1 , wherein the method further comprises detecting the presence of Candida albicans.

6. The method of claim 1 , wherein the subject is a mammal.

7. The method of claim 1 , wherein an amount or pattern of one or more volatile organic compounds is detected and wherein the amount or pattern is indicative of the degree of the pneumonia.

8. The method of claim 1 , wherein the detecting of the compound is performed using a differential mobility.

9. The method of claim 1 , further comprising the step

d) detecting the presence of at least one bacterium selected from the group of Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae and Haemophilus influenzae using a method not involving a volatile organic compound.

10. The method of claim 5 , wherein the detecting the presence of Candida albicans is by detecting the presence of ethyl butyrate, isopentyl propionate, 2-methylbutyl acetate, and/or vinyl ethyl ether.

11. The method of claim 1 , wherein the subject is human.

12. The method of claim 1 , further comprising a step of identifying the microorganism having infected the subject.

13. The method of claim 12 , wherein the step of identifying comprises a method selected from the group consisting of a DNA-based method, an immunoassay-based method, and an immune latex agglutination-based method.

14. The method of claim 1 , further comprising detecting 2-nonanone and/or dimethyldisulfide in the subject's respiratory air sample, wherein the presence of 2-nonanone and/or dimethyldisulfide is indicative of the existing or developing acute pneumonia.

15. The method of claim 14 , wherein one or more volatile organic compound(s) selected from the group consisting of methyl methacrylate and dimethyldisulfide is indicative of the presence of: Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae and/or Haemophilus influenza.

16. A method of detecting one or more volatile organic compound(s) in a subject's respiratory air sample, wherein the volatile organic compound(s) is detected in the respiratory air sample without culturing the respiratory air sample prior to the detecting and wherein the volatile organic compound is selected from the group consisting of 2-ethylacrolein, 2-methyl-2-butenal (Z), ethyl formate, ethyl isovalerate, isopentyl acetate, hydroxyacetone, 2-butanol, 2-methylbutyl 2-methylbutyrate, 2-methylbutyl isobutyrate, amyl isovalerate, ethyl 2-methylbutyrate, isoamyl butyrate, methyl 2-methylbutyrate, 1,10-undecadiene, 10-methyl-1-undecene, 1-decene, 1-nonene, 1-vinyl aziridine, mercaptoacetone, 3-phenylfuran, 3-(methylthio)propanal, o-hydroxybenzaldehyde, methyl propionate, vinyl butyrate, 2-acetyl-1,4,5,6-tetrahydropyridine, S-methyl thioacetate, 3-methyl-1-butanol, 3-(ethylthio)-propanal, 1-butanol, and methyl methacrylate.

17. The method of claim 16 , further comprising detecting 2-nonanone and/or dimethyldisulfide and/or dimethyltrisulfide (DMTS) in the subject's respiratory air sample.

18. The method of claim 16 , wherein the detecting is by gas chromatography combined with mass spectrometric detection (GC-MS), proton transfer reaction mass spectrometry (PTR-MS), selected ion flow tube mass spectrometry (SIFT-MS), ion mobility spectrometry (IMS), laser spectroscopy, electronic nose or photo acoustic spectroscopy.

19. The method of claim 16 , wherein the detecting of the compound is performed using a differential mobility.

20. The method of claim 16 , wherein

a) one or more volatile organic compound(s) selected from the group consisting of 2-methyl-1-propanol, 2-ethylacrolein, 2-methyl-2-butenal (Z), ethyl formate, ethyl isovalerate, isopentyl acetate and hydroxyacetone are detected; and/or

b) one or more volatile organic compound(s) selected from the group consisting of 2-butanol, 2-methylbutyl 2-methylbutyrate, 2-methylbutyl isobutyrate, amyl isovalerate, ethyl 2-methylbutyrate, isoamyl butyrate, methyl 2-methylbutyrate, 1,10-undecadiene, 10-methyl-1-undecene, 1-decene, 1-nonene, 1-vinyl aziridine, 2-methoxy-5-methylthiophene and mercaptoacetone are detected; and/or

c) one or more volatile organic compound(s) selected from the group consisting of 3-phenylfuran and 3-(methylthio)propanal are detected; and/or

d) one or more volatile organic compound(s) selected from the group consisting of o-hydroxybenzaldehyde, methyl propionate, vinyl butyrate, 2-acetyl-1,4,5,6-tetrahydropyridine and S-methyl thioacetate are detected; and/or

e) the volatile organic compound 3-methyl-1-butanol is detected; and/or

f) the volatile organic compound 2-nonanone is detected; and/or

g) the volatile organic compound 3-(ethylthio)-propanal is detected; and/or

h) the volatile organic compound 1-butanol is detected.

21. The method of claim 17 , wherein one or more volatile organic compound(s) selected from the group consisting of methyl methacrylate and dimethyldisulfide are detected.