Below is a 50-item Borrelia debris / inflammatory-particle master list. I am separating two different scientific questions:
A. Has the material actually been shown to persist after Borrelia loses viability or after antibiotic treatment?
B. Is the molecule a Borrelia component capable of provoking inflammation if released as debris?
Only a subset has strong direct evidence for post-killing persistence, particularly peptidoglycan, DNA, RNA for a limited period, and tissue-associated borrelial antigens.
1. Borrelia Peptidoglycan — PG^Bb
Evidence: VERY STRONG — HUMAN POST-TREATMENT
Borrelial peptidoglycan was detected in 32 of 34 Lyme-arthritis synovial-fluid samples, including many from previously antibiotic-treated patients. PG^Bb can therefore remain after viable organisms are no longer demonstrable and may sustain inflammatory signaling.
Full reference:
Jutras BL, Lochhead RB, Kloos ZA, Biboy J, Strle K, Booth CJ, Govers SK, Gray J, Schumann P, Vollmer W, Bockenstedt LK, Steere AC, Jacobs-Wagner C. Borrelia burgdorferi peptidoglycan is a persistent antigen in patients with Lyme arthritis. Proceedings of the National Academy of Sciences of the United States of America. 2019;116(27):13498-13507. doi:10.1073/pnas.1904170116.
2. Peptidoglycan Muropeptides
Evidence: STRONG
Borrelia sheds peptidoglycan fragments rather than efficiently recycling them. These muropeptides are biologically active and capable of driving innate immune responses.
Full reference:
Jutras BL, Lochhead RB, Kloos ZA, et al. Borrelia burgdorferi peptidoglycan is a persistent antigen in patients with Lyme arthritis. Proc Natl Acad Sci U S A. 2019;116(27):13498-13507. doi:10.1073/pnas.1904170116.
3. NOD2-Active Peptidoglycan Fragments
These are immunostimulatory products derived from Borrelia PG. Their importance is that bacterial killing need not immediately terminate inflammatory recognition.
Full reference:
Jutras BL, Lochhead RB, Kloos ZA, et al. Borrelia burgdorferi peptidoglycan is a persistent antigen in patients with Lyme arthritis. Proc Natl Acad Sci U S A. 2019;116(27):13498-13507. doi:10.1073/pnas.1904170116.
4. Large Cell-Wall Peptidoglycan Fragments
Cell lysis can liberate larger PG structures in addition to soluble muropeptides.
Full reference:
Jutras BL, Lochhead RB, Kloos ZA, et al. Borrelia burgdorferi peptidoglycan is a persistent antigen in patients with Lyme arthritis. PNAS. 2019;116:13498-13507. doi:10.1073/pnas.1904170116.
5. Cartilage-Associated Borrelia Antigen
Evidence: STRONG — MAMMAL POST-TREATMENT
Borrelial antigenic material persisted close to cartilage following antimicrobial therapy in mice even when infectious organisms were not recovered.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. Journal of Clinical Investigation. 2012;122(7):2652-2660. doi:10.1172/JCI58813.
6. Whole Noninfectious Spirochetal Remnants
Antibiotic-treated organisms can leave morphologically recognizable but noninfectious bacterial structures.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122(7):2652-2660. doi:10.1172/JCI58813.
7. Fragmented Spirochetal Bodies
Ceftriaxone-treated Borrelia rapidly lost cultivability while cellular fragmentation occurred thereafter.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. Journal of Clinical Microbiology. 2013;51(3):857-862. doi:10.1128/JCM.02785-12.
8. Borrelia Genomic DNA
Evidence: VERY STRONG — POST-KILLING IN VITRO
Cultivable Borrelia disappeared by day 3 after ceftriaxone, yet DNA remained PCR-positive through day 56.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51(3):857-862. doi:10.1128/JCM.02785-12.
9. ospA DNA
This was specifically used as a PCR target and remained detectable to day 56 despite loss of cultivability.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
10. Plasmid DNA Fragments
Because ospA is plasmid encoded, antibiotic-treated Borrelia can leave detectable plasmid-derived DNA as part of residual nucleic-acid debris.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
11. Chromosomal DNA Fragments
Loss of bacterial viability does not mean immediate nuclease destruction of the bacterial chromosome.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
12. Borrelia RNA
Borrelial RNA can stimulate human innate immune responses through nucleic-acid sensing.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infection and Immunity. 2014;82(6):2405-2416.
13. ospA mRNA
Some ospA transcripts persisted transiently after ceftriaxone despite loss of cultivability.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
14. ospC mRNA
Certain ospC transcripts remained measurable following lethal antibiotic exposure.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
15. flaB mRNA
Residual flaB transcript was among the RNAs specifically studied after ceftriaxone exposure.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
16. pfk mRNA
This metabolic transcript was also detectable for a limited interval after loss of normal viability.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
17. RNA Fragments Delivered to Endosomes
Borrelia RNA can activate TLR7 and induce interferon signaling in human PBMCs.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infect Immun. 2014;82(6):2405-2416.
18. DNA Fragments Reaching Intracellular TLR9
Phagocytosis and degradation of Borrelia can expose its nucleic acids to intracellular pattern-recognition receptors.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infect Immun. 2014;82(6):2405-2416.
Lipoprotein Debris
For items 19-35, the molecules are well-established Borrelia antigens/inflammatory molecules. Their ability to remain as bacterial debris is biologically plausible, but long-term persistence after antibiotic killing has generally not been demonstrated individually in humans.
19. OspA Lipoprotein
A potent triacylated Borrelia lipoprotein that activates TLR2-containing pathways.
Full reference:
Bulut Y, Faure E, Thomas L, Equils O, Arditi M. Cooperation of Toll-like receptor 2 and 6 for cellular activation by soluble tuberculosis factor and Borrelia burgdorferi outer surface protein A lipoprotein. Journal of Immunology. 2001;167(2):987-994. doi:10.4049/jimmunol.167.2.987.
20. Lipidated OspA
The N-terminal lipid moiety is crucial for its inflammatory activity.
Full reference:
Erdile LF, Guy B, O’Reilly DM. OspA lipoprotein of Borrelia burgdorferi is a mucosal immunogen and adjuvant. Vaccine. 1997;15(9):988-995. doi:10.1016/S0264-410X(96)00295-2.
21. OspA Pam3Cys Lipid Moiety
The tripalmitoyl-S-glyceryl-cysteine portion is a particularly potent innate-immune stimulus.
Full reference:
Erdile LF, Guy B, O’Reilly DM. OspA lipoprotein of Borrelia burgdorferi is a mucosal immunogen and adjuvant. Vaccine. 1997;15:988-995. doi:10.1016/S0264-410X(96)00295-2.
22. OspC
OspC is another major lipidated outer-surface antigen and is present in Borrelia lysates capable of activating innate immune pathways.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infect Immun. 2014;82:2405-2416.
23. OspC Lipid Anchor
Like other Borrelia lipoproteins, its acylated N-terminus is capable of TLR2-family recognition.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infect Immun. 2014;82:2405-2416.
24. Generic Triacylated Borrelia Lipoproteins
Borrelia possesses an unusually large repertoire of lipidated proteins; these are major TLR2/1 inflammatory agonists.
Full reference:
Bulut Y, Faure E, Thomas L, Equils O, Arditi M. Cooperation of Toll-like receptor 2 and 6 for cellular activation by soluble tuberculosis factor and Borrelia burgdorferi outer surface protein A lipoprotein. J Immunol. 2001;167:987-994. doi:10.4049/jimmunol.167.2.987.
25. Lipoprotein Lipid Anchors
Even proteolysis of the protein portion may leave lipidated peptide fragments capable of immune recognition.
Full reference:
Erdile LF, Guy B, O’Reilly DM. OspA lipoprotein of Borrelia burgdorferi is a mucosal immunogen and adjuvant. Vaccine. 1997;15:988-995. doi:10.1016/S0264-410X(96)00295-2.
26. Decorin-Binding Protein A — DbpA
DbpA binds extracellular-matrix decorin and is therefore relevant to retention of Borrelia material in connective tissues.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122:2652-2660. doi:10.1172/JCI58813.
27. Decorin-Binding Protein B — DbpB
DbpB is another ECM-binding Borrelia protein potentially relevant to tissue localization of antigenic material.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122:2652-2660. doi:10.1172/JCI58813.
28. Decorin-Bound Borrelia Antigen Complexes
Matrix binding offers a plausible physical mechanism by which killed-bacterial proteins can avoid immediate clearance.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122:2652-2660. doi:10.1172/JCI58813.
29. Collagen-Associated Borrelia Antigen
Connective-tissue niches can retain bacterial antigen after antimicrobial treatment.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122:2652-2660. doi:10.1172/JCI58813.
30. Extracellular-Matrix-Bound Protein Debris
This is a broader category encompassing retained Borrelia proteins associated with matrix structures.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122:2652-2660. doi:10.1172/JCI58813.
Glycolipid and Membrane Debris
31. BbGL-I
Also called acylated cholesteryl galactoside (ACG).
It is a major surface-exposed Borrelia glycolipid and highly immunogenic in Lyme arthritis.
Full reference:
Schröder NWJ, Schombel U, Heine H, Göbel UB, Zähringer U, Schumann RR. Acylated cholesteryl galactoside as a novel immunogenic motif in Borrelia burgdorferi. Journal of Biological Chemistry. 2003;278:33645-33653.
32. Cholesteryl 6-O-Acyl-β-D-Galactopyranoside
This is the chemically defined structure of BbGL-I.
Full reference:
Ben-Menachem G, Kubler-Kielb J, Coxon B, Yergey A, Schneerson R. A newly discovered cholesteryl galactoside from Borrelia burgdorferi. Proceedings of the National Academy of Sciences USA. 2003;100(13):7913-7918.
33. BbGL-II
Also called monogalactosyl diacylglycerol.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, Marques A, Robbins JB, Schneerson R. Synthesis and antigenicity of BBGL-2 glycolipids of Borrelia burgdorferi, the causative agent of Lyme disease. Carbohydrate Research. 2011;346(12):1551-1563. doi:10.1016/j.carres.2011.04.045.
34. Monogalactosyl Diacylglycerol
This is another name for BbGL-II and elicits strong antibody responses in late Lyme disease.
Full reference:
Jones KL, Seward RJ, Ben-Menachem G, Glickstein LJ, Costello CE, Steere AC. Strong IgG antibody responses to Borrelia burgdorferi glycolipids in patients with Lyme arthritis, a late manifestation of the infection. Clinical Immunology. 2009;132(1):93-104.
35. α-Galactosyl Diacylglycerol
One structurally characterized class of Borrelia glycolipids.
Full reference:
Hossain H, Wellensiek HJ, Geyer R, Lochnit G. Structural analysis of glycolipids from Borrelia burgdorferi. Biochimie. 2001;83(7):683-692.
36. Oleoyl-Containing BbGL-II
Oleic acid is a major fatty-acid constituent important for antigenicity of BBGL-II.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, et al. Synthesis and antigenicity of BBGL-2 glycolipids of Borrelia burgdorferi. Carbohydr Res. 2011;346:1551-1563. doi:10.1016/j.carres.2011.04.045.
37. Palmitoyl-Containing BbGL-II
Palmitic acid is another major constituent of the glycolipid.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, et al. Synthesis and antigenicity of BBGL-2 glycolipids of Borrelia burgdorferi. Carbohydr Res. 2011;346:1551-1563. doi:10.1016/j.carres.2011.04.045.
38. Stearoyl-Containing Glycolipid Species
Stearate-containing species occur among Borrelia membrane glycolipids.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, et al. Synthesis and antigenicity of BBGL-2 glycolipids of Borrelia burgdorferi. Carbohydr Res. 2011;346:1551-1563. doi:10.1016/j.carres.2011.04.045.
39. Myristoyl-Containing Glycolipid Species
Myristic acid occurs among the minor fatty-acid constituents.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, et al. Carbohydr Res. 2011;346:1551-1563. doi:10.1016/j.carres.2011.04.045.
40. Linoleoyl-Containing Glycolipid Species
Linoleic acid has also been identified in BbGL-II preparations.
Full reference:
Pozsgay V, Kubler-Kielb J, Coxon B, et al. Carbohydr Res. 2011;346:1551-1563. doi:10.1016/j.carres.2011.04.045.
41. Phosphatidylcholine
Borrelia membranes contain phosphatidylcholine, which may be released with membrane disruption.
Full reference:
Hossain H, Wellensiek HJ, Geyer R, Lochnit G. Structural analysis of glycolipids from Borrelia burgdorferi. Biochimie. 2001;83(7):683-692.
42. Phosphatidylglycerol
Another identified Borrelia membrane phospholipid.
Full reference:
Hossain H, Wellensiek HJ, Geyer R, Lochnit G. Structural analysis of glycolipids from Borrelia burgdorferi. Biochimie. 2001;83(7):683-692.
43. Cholesterol-Containing Membrane Fragments
Borrelia incorporates host-derived cholesterol into its membrane and glycolipids.
Full reference:
Ben-Menachem G, Kubler-Kielb J, Coxon B, Yergey A, Schneerson R. A newly discovered cholesteryl galactoside from Borrelia burgdorferi. Proc Natl Acad Sci U S A. 2003;100:7913-7918.
44. Outer-Membrane Fragments
Killing and structural disintegration inevitably releases pieces of the Borrelia outer membrane containing lipoproteins and lipids.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
45. Membrane Vesicular Debris
Fragments generated during disintegration may package lipid, proteins and nucleic acids together.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
Flagellar / Protein Debris
46. FlaB Protein
FlaB is a major periplasmic flagellar protein; breakdown of organisms can release flagellar antigen.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
47. Periplasmic Flagellar Fragments
Physical disintegration can leave flagellar fragments as bacterial protein debris.
Full reference:
Iyer R, Mukherjee P, Wang K, Simons J, Wormser GP, Schwartz I. Detection of Borrelia burgdorferi nucleic acids after antibiotic treatment does not confirm viability. J Clin Microbiol. 2013;51:857-862. doi:10.1128/JCM.02785-12.
48. Proteinaceous Borrelia Antigen Remnants
Even after bacterial nucleic acids become degraded, relatively stable protein antigens may remain sequestered in tissue.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. J Clin Invest. 2012;122(7):2652-2660. doi:10.1172/JCI58813.
49. Borrelia Lysate Particles
Killed/disrupted Borrelia produces mixtures containing lipoproteins, nucleic acids and other PAMPs capable of activating human immune cells.
Full reference:
Petnicki-Ocwieja T, Chung E, Acosta DI, et al. Borrelia burgdorferi RNA induces type I and III interferons via Toll-like receptor 7 and contributes to production of NF-κB-dependent cytokines. Infection and Immunity. 2014;82(6):2405-2416.
50. Mixed Cartilage-Sequestered Borrelia Debris
This may be the most clinically interesting category after PG: a mixture of protein, cell-envelope and other antigenic remnants retained in connective tissue, rather than an intact actively replicating spirochete.
Full reference:
Bockenstedt LK, Gonzalez DG, Haberman AM, Belperron AA. Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy. Journal of Clinical Investigation. 2012;122(7):2652-2660. doi:10.1172/JCI58813.
The Most Defensible “Top 10” Persistent Borrelia Materials
Based specifically on evidence after killing or treatment, rather than merely knowing that a molecule occurs in Borrelia, I would put the strongest candidates in roughly this order:
Peptidoglycan PG^Bb — human evidence
Peptidoglycan muropeptides
Cartilage-associated Borrelia antigens — mammalian evidence
Proteinaceous spirochetal remnants
Whole/fragmented noninfectious spirochetal material
Borrelia genomic DNA
ospA DNA/plasmid DNA
Other genomic DNA fragments
Borrelia RNA/mRNA — shorter-lived than DNA
Membrane/lipoprotein-containing debris
The striking quantitative findings are that PG^Bb was detected in 94% (32/34) of tested Lyme-arthritis synovial fluids, many after substantial antibiotic therapy, while experimentally Borrelia DNA remained detectable for 56 days after ceftriaxone even though the organisms were no longer successfully subcultured by day 3.
One crucial qualification: items such as OspA, OspC, glycolipids, phospholipids and flagellar proteins are unquestionably Borrelia components and can be immunogenic/inflammatory, but current evidence does not establish that each individually remains for months in treated humans. The evidence for actual prolonged human persistence is strongest for peptidoglycan, while tissue-retained protein antigen is especially well demonstrated in mouse Lyme disease.
For Gutenberg, use Heading 4 for the article title and the major section headings such as Lipoprotein Debris, Glycolipid and Membrane Debris, Flagellar / Protein Debris, and The Most Defensible “Top 10” Persistent Borrelia Materials. Use Heading 5 for each of the numbered items 1 through 50.