Cell-free nucleic acids for the analysis of the human microbiome and components thereof
Methods, devices, compositions and kits are provided for analysis of the microbiome or individual components thereof in an individual. The methods find use in a determination of infection, in analysis of the microbiome structure, in determining the immunocompetence of an individual, and the like. In some embodiments of the invention, the individual is treated with an therapeutic regimen, e.g. drugs, diet, radiation therapy, and the like.
1. A method of processing a sample from a human subject, the method comprising:
(a) providing a biological sample selected from the group consisting of plasma, serum, cerebrospinal fluid, and synovial fluid, wherein the biological sample is obtained from a human subject and comprises cell-free nucleic acids, wherein the cell-free nucleic acids comprise microbial cell-free nucleic acids;
(b) separating cells and their fragments from the cell-free nucleic acids in the biological sample using a process that includes centrifuging the biological sample at a force that is at least 4,500 g to generate a biological cell-free sample;
(c) performing high-throughput sequencing on the cell-free nucleic acids and generating at least 1,000 sequence reads from the cell-free nucleic acids;
(d) aligning a portion of the at least 1,000 sequence reads from the cell-free nucleic acids with a plurality of microbial reference sequences to obtain a plurality of alignments; and
(e) using the plurality of alignments to identify microbial nucleic acids in the biological sample.
2. The method of claim 1 , further comprising extracting the cell-free nucleic acids from the biological sample.
3. The method of claim 1 , wherein the cell-free nucleic acids comprise cell-free DNA.
4. The method of claim 3 , further comprising extracting the cell-free DNA from the biological cell-free sample.
5. The method of claim 1 , wherein the cell-free nucleic acids comprise cell-free RNA and further comprising extracting the cell-free RNA from the biological cell-free sample.
6. The method of claim 1 , wherein (e) comprises using the plurality of alignments to identify bacterial nucleic acids in the biological sample.
7. The method of claim 1 , wherein (e) comprises using the plurality of alignments to identify viral nucleic acids in the biological sample.
8. The method of claim 1 , wherein (e) comprises using the plurality of alignments to identify fungal nucleic acids in the biological sample.
9. The method of claim 1 , wherein (e) comprises using the plurality of alignments to identify parasite nucleic acids in the biological sample.
10. The method of claim 1 , wherein the microbial nucleic acids identified in the biological sample comprise nucleic acids from:
(i) at least one virus selected from the group consisting of: adenovirus, adeno-associated virus, anellovirus, human cytomegalovirus, human respiratory syncytial virus, human rhinovirus, human influenza virus, human coronavirus, human SARS coronavirus, hepatitis virus, cytomegalovirus, parainfluenza virus, human papillomavirus, Epstein-Barr virus, and human T-lymphotropic virus;
(ii) at least one bacterium selected from the group consisting of: Brucella, Treponema, Mycobacterium, Listeria, Helicobacter, Legionella, Streptococcus, Neisseria, Clostridium, Staphylococcus, Pseudomonas, Micrococcus , Multi-drug resistant Staphylococcus Aureus (MRSA), Klebsiella pneumonia , gram positive bacteria, gram negative bacteria, and Bacillus;
(iii) at least one parasite selected from the group consisting of: Trichomonas, Toxoplasma, Giardia, Cryptosporidium, Plasmodium, Leishmania, Trypanosoma, Entamoeba, Schistosoma , Filariae, Ascaria, and Fasciola;
(iv) at least one fungus selected from the group consisting of: Candida, Aspergillus , and yeast; or
(v) any combination thereof.
11. The method of claim 1 , wherein the centrifuging the biological sample at a force that is at least 4,500 g comprises centrifuging the biological sample at force that is at least 10,000 g to generate a biological cell-free sample.
12. The method of claim 1 , wherein the centrifuging the biological sample at a force that is at least 4,500 g comprises centrifuging the biological sample at force that is 4,500 g to 20,000 g to generate a biological cell-free sample.
13. The method of claim 1 , wherein the biological sample is a plasma sample.
14. The method of claim 1 , wherein the biological sample is a plasma sample extracted from whole blood within three hours of collection of the whole blood.
15. The method of claim 1 , further comprising attaching adapters to the cell-free nucleic acids.
16. The method of claim 15 , further comprising amplifying the cell-free nucleic acids using primers specific for the adapters.
17. The method of claim 1 , further comprising amplifying the cell-free nucleic acids.
18. The method of claim 17 , wherein the amplifying the cell-free nucleic acids comprises performing non-biased amplification of the cell-free nucleic acids.
19. The method of claim 1 , further comprising using the plurality of alignments to identify human sequence reads.
20. The method of claim 19 , further comprising removing the human sequence reads when identifying the microbial nucleic acids.
21. The method of claim 1 , further comprising using the plurality of alignments to determine a quantity of microbial nucleic acids in the biological sample.
22. The method of claim 21 , further comprising using the quantity of microbial nucleic acids in the biological sample to detect infection in the human subject.
23. The method of claim 22 , further comprising administering an antimicrobial treatment to the human subject to treat the infection.
24. The method of claim 1 , wherein (b) generates at least 10,000,000 sequence reads.
25. The method of claim 1 , wherein (b) generates at least 100,000,000 sequence reads.
26. The method of claim 1 , further comprising detecting antimicrobial resistance in the microbial nucleic acids based on the sequence reads from the microbial nucleic acids.
27. The method of claim 1 , further comprising obtaining a second sample from the subject with an infection at a second time point and performing (b)-(e) on the second sample.
28. The method of claim 27 , wherein the second time point is a time point following administration of an antimicrobial treatment to the human subject, and further comprising detecting a decrease in quantity of the microbial nucleic acids in response to the antimicrobial treatment.
29. The method of claim 1 , further comprising predicting infection in the human subject based at least in part on using the plurality of alignments to identify microbial nucleic acids in the biological sample.