The strongest direct persistence evidence is for peptidoglycan in human Lyme arthritis, cartilage-associated antigens in treated mice, and DNA/mRNA persistence after lethal ceftriaxone exposure in vitro.
Evidence Key
H = human evidence; M = mammal/animal; V = in vitro.
Persistence: ★★★ direct post-treatment/post-killing evidence; ★★ suggestive/indirect; ★ component established but persistence itself unproven.
| # | Particle / Borrelia Material | Persistence / Approximate Duration | Main Location | Receptor / Pathway | Major Inflammatory Signals | Possible Inflammatory Relevance | Evidence | Key Reference |
|---|---|---|---|---|---|---|---|---|
| 1 | PG^Bb polymeric peptidoglycan | ★★★ Human post-treatment; duration not precisely defined | Synovial fluid/joints | NOD2; innate PRRs | TNF-α, IL-1α/β, IL-6, IL-8, IL-17F | Persistent Lyme arthritis | H/M/V | Jutras 2019 |
| 2 | PG^Bb muropeptides | ★★★ shed continuously; potentially retained | Joint/ECM | NOD2 | IL-1, IL-6, TNF | Synovitis | H/V | Jutras 2019 |
| 3 | Polymeric PG fragments | ★★★ weeks in mouse liver demonstrated in newer work | Liver, joint | NOD2/innate signaling | inflammatory protein responses | Persistent antigen inflammation | M | Recent PG persistence study |
| 4 | Soluble PG fragments | ★★ | Synovial fluid | NOD2 | IL-6, IL-8, TNF | Arthritis | H/V | Jutras 2019 |
| 5 | PG-associated peptide stems | ★★ | Joint fluid/tissue | NOD family | innate cytokines | Synovitis | H/V | Jutras 2019 |
| 6 | PG glycan backbone fragments | ★★ | Joint/liver | innate PG recognition | cytokine induction | Chronic antigen exposure | H/M/V | Jutras 2019 |
| 7 | Cartilage-associated Borrelia antigen | ★★★ extended period after antibiotics in mice | Cartilage/entheses | macrophage PRRs | TNF-α | Post-antibiotic arthritis model | M | Bockenstedt 2012 |
| 8 | Amorphous spirochetal antigen deposits | ★★★ visualized after therapy | Entheses/cartilage | innate immune recognition | TNF-α | Local inflammation | M | Bockenstedt 2012 |
| 9 | Noninfectious spirochetal remnants | ★★★ after antibiotic therapy | Connective tissues | multiple PRRs | TNF-α | Persistent inflammatory antigen | M | Bockenstedt 2012 |
| 10 | ECM-bound Borrelia debris | ★★★/★★ | Cartilage/ECM | multiple | TNF-α | Tissue-localized inflammation | M | Bockenstedt 2012 |
| 11 | Genomic DNA | ★★★ up to 56 days in vitro after loss of cultivability | Cellular debris/culture | TLR9/cytosolic DNA sensors conceptually | IFN-related pathways | Residual molecular signal | V | Iyer 2013 |
| 12 | ospA DNA | ★★★ detected through 56 days after ceftriaxone | DNA-containing debris | DNA sensors | innate signaling potentially | PCR positivity without viability | V | Iyer 2013 |
| 13 | Chromosomal DNA fragments | ★★★ concept supported by persistent PCR signal | Debris/phagosomes | TLR9 | interferon pathways | Persistent antigenic material | V | Iyer 2013 |
| 14 | Plasmid-derived DNA | ★★★/★★ | Cellular debris | DNA sensors | IFN-related | Molecular persistence | V | Iyer 2013 |
| 15 | CpG-rich Borrelia DNA fragments | ★ | Phagolysosomes | TLR9 | type-I IFN/proinflammatory pathways | Innate immune stimulation | V/mechanistic | Iyer 2013 + innate-immunity literature |
| 16 | Borrelia total RNA | ★★ shorter-lived than DNA | Endosomal compartments | TLR7 | IFN-α/β, IFN-λ, NF-κB cytokines | Innate inflammation | V/H-cell | Petnicki-Ocwieja 2014 |
| 17 | ospA mRNA | ★★★ detectable to ~3 days after ceftriaxone in study | Cellular debris | RNA sensors | interferon pathways | Marker can outlast viability | V | Iyer 2013 |
| 18 | ospC mRNA | ★★★ ~3 days in ceftriaxone experiment | Debris | RNA sensors | IFN/NF-κB | Residual RNA | V | Iyer 2013 |
| 19 | pfk mRNA | ★★★ detectable to ~7 days | Debris | RNA sensors | IFN-related | Residual RNA | V | Iyer 2013 |
| 20 | pyk mRNA | ★★★ detectable to ~7 days | Debris | RNA sensors | IFN-related | Residual RNA | V | Iyer 2013 |
| 21 | eno mRNA | ★★★ detected through ~3 days | Debris | RNA sensors | interferon pathways | Residual RNA | V | Iyer 2013 |
| 22 | RNA fragments in phagosomes | ★★ | Monocytes/macrophages | TLR7 | type I/III IFNs; NF-κB cytokines | Innate activation | V/H cells | Petnicki-Ocwieja 2014 |
| 23 | OspA lipoprotein | ★ persistence individually unproven in treated humans | Outer membrane/debris | TLR1/TLR2/CD14 | TNF-α, IL-6, IL-8, NF-κB | Potent inflammation | H-cell/M/V | Hirschfeld 1999 |
| 24 | OspA Pam3Cys lipid anchor | ★ | Membrane fragments | TLR1/2 | TNF, IL-6, IL-8 | Innate activation | M/V | Erdile 1997 |
| 25 | OspB | ★ | Outer membrane | TLR2-type lipoprotein pathway | IL-6, B-cell activation | Inflammation/immunogenicity | V/M | Ma & Weis 1993 |
| 26 | OspC | ★ | Membrane fragments | TLR1/2 as lipidated bacterial lipoprotein | NF-κB cytokines | Early immune activation | V | Borrelia lipoprotein literature |
| 27 | Generic triacylated Borrelia lipoproteins | ★ | Outer membrane/debris | TLR1/TLR2 | TNF-α, IL-6, IL-8 | Major Borrelia PAMP class | H-cell/V/M | Hirschfeld 1999 |
| 28 | Lipidated peptide fragments | ★ | Membrane/protein debris | TLR1/2 | TNF, IL-6 | Inflammatory debris | V | Hirschfeld 1999 |
| 29 | Palmitoylated membrane proteins | ★ | Outer membrane | TLR2 family | NF-κB | Immunogenic debris | V | Brandt et al. membrane-protein studies |
| 30 | DbpA | ★★ ECM-binding makes retention plausible | Decorin-rich connective tissue | immune recognition; adhesin interactions | indirect inflammatory effects | Tissue localization | M/V | Bockenstedt 2012 + Dbp literature |
| 31 | DbpB | ★★ | ECM/decorin | adhesin/immune recognition | indirect | Tissue localization | M/V | Bockenstedt 2012 |
| 32 | Decorin–Dbp complexes | ★★ | Collagen-rich ECM | antigen-processing pathways | inflammatory antigen presentation | Retained antigen concept | M | Bockenstedt 2012 |
| 33 | Collagen-associated protein debris | ★★ | Cartilage/entheses | macrophage PRRs | TNF | Persistent joint inflammation | M | Bockenstedt 2012 |
| 34 | Proteinaceous spirochetal antigens | ★★★ in treated mice | Cartilage | multiple PRRs | TNF-α | Post-treatment inflammation | M | Bockenstedt 2012 |
| 35 | BbGL-I / ACGal | ★ persistence not directly shown | Membrane | immune recognition, antibody targets | immunogenic | Lyme arthritis immune responses | H/V | Jones 2009 |
| 36 | Cholesteryl 6-O-acyl-β-D-galactopyranoside | ★ | Membrane | lipid-antigen pathways | immunogenic response | Arthritis seroreactivity | H/V | Jones 2009 |
| 37 | Cholesterol-β-D-galactopyranoside | ★ | Membrane | lipid recognition | immunogenicity | Membrane antigen | V | Borrelia lipid studies |
| 38 | BbGL-II / MGalD | ★ | Membrane | antibody/lipid recognition | strong humoral response | Lyme arthritis antigen | H/V | Jones 2009 |
| 39 | α-galactosyl diacylglycerol | ★ | Membrane | immune lipid recognition | antibody response | Immunogenic debris | H/V | Pozsgay 2011 |
| 40 | Oleoyl-BbGL-II species | ★ | Membrane | antibody recognition | antigenicity | Immune stimulation | V/H sera | Pozsgay 2011 |
| 41 | Palmitoyl-BbGL-II species | ★ | Membrane | lipid-antigen recognition | antigenicity varies | Immune response | V | Pozsgay 2011 |
| 42 | Stearoyl glycolipid species | ★ | Membrane | lipid-antigen pathways | lower/variable antigenicity | Immune recognition | V | Pozsgay 2011 |
| 43 | Linoleoyl glycolipid species | ★ | Membrane | lipid recognition | immunogenic potential | Membrane antigen | V | Pozsgay 2011 |
| 44 | Myristoyl glycolipid species | ★ | Membrane | lipid recognition | immunogenic potential | Membrane antigen | V | Pozsgay 2011 |
| 45 | Phosphatidylcholine | ★ | Membrane fragments | not established as dominant Borrelia PAMP | uncertain | Structural debris | V | Borrelia membrane lipid study |
| 46 | Phosphatidylglycerol | ★ | Membrane fragments | lipid-sensing pathways possible | uncertain | Structural debris | V | Borrelia membrane lipid study |
| 47 | Free cholesterol in membrane fragments | ★ | Outer membrane | no specific Lyme inflammatory receptor established | uncertain | Membrane-remnant biology | V | Borrelia membrane lipid study |
| 48 | Cholesterol-esters / cholesterol-rich membrane domains | ★ | Membrane fragments | lipid-associated recognition | uncertain | Structural debris | V | Borrelia lipid-domain study |
| 49 | FlaA/p37 flagellar fragments | ★ | Periplasmic flagella/debris | TLR5 activity reported for FlaA/p37 | TLR5-associated signaling | Potential innate stimulation | H-cell/V | Cabral et al. |
| 50 | FlaB / flagellar protein debris | ★ persistence unproven; structural debris expected after lysis | Periplasmic flagella | notably, whole-Borrelia inflammatory signaling is not primarily TLR5/FlaB driven | weaker/uncertain | Antigenic rather than proven persistent inflammatory driver | V | Salazar et al. 2009 |
The Strongest Findings
1. Peptidoglycan Is Currently the Strongest Human Example.
Jutras and colleagues detected PG^Bb in 32/34 (94%) Lyme-arthritis synovial-fluid specimens, many obtained after oral and IV antibiotic treatment. PG^Bb stimulated human PBMC inflammatory responses, and systemic PG administration induced arthritis in mice.
2. Borrelia Antigen Deposits Can Outlast Viable Organisms in Mammals.
In antibiotic-treated mice, Bockenstedt et al. found spirochetal antigen deposits adjacent to cartilage despite negative culture and essentially negative xenodiagnosis; these antigen-containing homogenates stimulated macrophage TNF-α.
3. DNA Can Dramatically Outlast Cultivability.
In Iyer et al., ceftriaxone-treated organisms could no longer be successfully subcultured by day 3, whereas ospA DNA remained PCR detectable through day 56. Some mRNA targets remained detectable for days after cultivability disappeared.
4. Borrelial RNA Is Biologically Active.
B. burgdorferi RNA activates TLR7 and stimulates type-I/type-III interferon and NF-κB-dependent cytokine responses. Therefore bacterial RNA fragments are potentially inflammatory even though RNA is generally cleared much faster than DNA or polymeric peptidoglycan.
5. Borrelia Lipoproteins Are Among Its Strongest Innate Immune Agonists.
OspA and related triacylated lipoproteins activate predominantly TLR1/TLR2, leading to NF-κB activation and cytokines including TNF-α, IL-6 and IL-8.
6. Borrelia Does Not Possess Classical LPS.
Its membrane instead contains abundant glycolipids, particularly ACGal/BbGL-I and MGalD/BbGL-II, plus phosphatidylcholine and phosphatidylglycerol.
Full Core References
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.
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.
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.
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.
Hirschfeld M, Kirschning CJ, Schwandner R, Wesche H, Weis JH, Wooten RM, Weis JJ. Cutting edge: inflammatory signaling by Borrelia burgdorferi lipoproteins is mediated by Toll-like receptor 2. Journal of Immunology. 1999;163(5):2382-2386.
Wooten RM, Ma Y, Yoder RA, Brown JP, Weis JH, Zachary JF, Kirschning CJ, Weis JJ. Toll-like receptor 2 is required for innate, but not acquired, host defense to Borrelia burgdorferi. Journal of Immunology. 2002;168(1):348-355. doi:10.4049/jimmunol.168.1.348.
Ma Y, Weis JJ. Borrelia burgdorferi outer surface lipoproteins OspA and OspB possess B-cell mitogenic and cytokine-stimulatory properties. Infection and Immunity. 1993;61(9):3843-3853. doi:10.1128/IAI.61.9.3843-3853.1993.
Erdile LF, Guy B. OspA lipoprotein of Borrelia burgdorferi is a mucosal immunogen and adjuvant. Vaccine. 1997;15(9):988-996. doi:10.1016/S0264-410X(96)00295-2.
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):93-102. doi:10.1016/j.clim.2009.03.510.
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.
A particularly important newer finding is that polymeric Borrelia peptidoglycan can accumulate in mouse liver and persist for weeks, with uptake by Kupffer cells and hepatocytes. That materially strengthens the concept that certain Borrelia cell-wall polymers can be cleared much more slowly than viable organisms themselves.