iiinova — where your digital self keeps evolving

Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 07/10/2026

Seemed like the main purpose of fax machines was to send jokes and cartoons

Cartoon of laughing people, captioned, "You want it when?"

Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 28/09/2026

MinD-like ATPase FlhG synchronizes flagellation and cell division in spirochetes Brilliant new paper from C. Li, J. Liu, and colleagues mBio: journals.asm.org/doi/10.1128/... #MicroSky

Fig 9 Model for FlhGBb-mediated coordination of flagellation and cell division in B. burgdorferi. In nascent cells, the ATPase FlhGBb localizes predominantly at the cell poles, where it recruits and spatially organizes FlhF and the MS-ring protein FliF to establish sites of basal body assembly. These events initiate the formation of polar PFs that assemble into ribbon-like bundles along the cell cylinder. As the cell cycle progresses, FlhGBb redistributes toward the midcell division zone, where it likely contributes to proper septum placement and coordination of cytokinesis with ongoing flagellar morphogenesis. In the absence of FlhGBb, FlhF and FliF become delocalized, basal bodies assemble at aberrant positions, and organized PF ribbon formation is disrupted, leading to defects in motility, cell morphology, and division. Through this ATPase-dependent spatial regulation, FlhGBb synchronizes flagellar assembly with cell division to maintain the distinctive architecture and motility of spirochetes.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 25/09/2026

Many hosts, many solutions: How reservoirs shape Borrelia protein diversity by S. Ciglbauerová, M. Strnad, and R.O. M. Rego PLoS Pathogens journals.plos.org/plospathogen... #MicroSky

Fig 1. Reservoir host communities drive the diversification of plasmid-encoded surface proteins in the Borrelia burgdorferi sensu lato complex.

(Left) Ixodes ticks cycle spirochetes through vertebrate reservoir communities, with distinct genospecies associating preferentially with different host groups: birds (B. garinii, B. valaisiana), lizards (B. lusitaniae), mice and shrews (B. afzelii, B. spielmanii, B. burgdorferi sensu stricto), and hedgehogs (B. afzelii, B. bavariensis). Double-headed arrows denote tick-mediated acquisition and transmission; several genospecies (e.g., B. afzelii) are shared across mammal groups rather than restricted to one host. (Center) Each genospecies carries a linear chromosome together with numerous linear and circular plasmids. Genes encoding host-interaction surface proteins (adhesins and immune-evasion factors, boxed area) are enriched on the plasmids, where they are subject to host-driven diversifying selection; conserved host-interaction genes such as p66 remain chromosomal. (Right) The encoded proteins are grouped by function: adhesion and dissemination (DbpA, DbpB, BBK32), complement evasion (CspZ, BBK32), antibody evasion and persistence (VlsE, OspC), and cellular immune evasion (P66). Filled in cicles represent proven host-linked variation, empty cirlces represent proposed host-linked variation and partially filled circles represent no current evidence for host-linked variation. The P66-CD47/SIRPa interaction is currently supported only by preprint data and should be regarded as preliminary.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 16/09/2026

“Anything can happen, and anything does” Annie Dillard, April 30, 1945 – September 15, 2026

Image of the cover of a paperback edition of "Pilgrim at Tinker Creek", by Annie Dillard

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 08/09/2026

Spirochetes do it differently! Evolutionary characterization and structure-guided discovery of the β-barrel assembly machinery in Treponema pallidum subsp. pallidum reveals a putative BamD-like protein www.sciencedirect.com/science/arti... #MicroSky

Figure 1. Workflow for the identification of components in the T. pallidum BAM system. This schematic illustrates the overall strategy used to identify and validate candidate components of the BAM system in T. pallidum. First, phylogenetic analysis of Omp85 family proteins and comparative analysis of bamA gene neighborhoods were performed to investigate the evolutionary features and genomic organization of BAM-associated components in Treponema and Borrelia. Subsequently, candidate BAM proteins were identified through two complementary approaches: (i) a structure-guided computational strategy based on structural similarity searches; and (ii) an experimental proteomic strategy using IP-MS analysis. Candidate proteins identified from both approaches were further evaluated by in vitro protein-protein interaction assays. Proteins exhibiting specific interaction with Tp0326 were subsequently subjected to domain identification, structural modeling and interface analysis.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 06/09/2026

Returning home after Brandon’s @jutraslab.bsky.social memorial / celebration of life. Part of the outline of my eulogy is attached. Life is a mystery We don’t know how many years, or hours, we have left to live Don’t put things off to the future Hug your friends Tell them that you love them

Part of the outline of my eulogy.

Life is a mystery
We don’t know how many years, or hours, we have left to live
Don’t put things off to the future
Hug your friends
Tell them that you love them

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 04/09/2026

Born in England. Lived in Alabama from 7-13, then Utah until age 24. Followed by several years each on Long Island, Connecticut, and Montana. Now 28 years in Kentucky. “He ain’t from here!”

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 04/09/2026

This weekend, we celebrate the life and honor the memory of Brandon Jutras. From one of Brandon’s PhD research notebooks. He wrote of creating a name for the previously-undescribed protein that he functionally defined. This weekend, we let his definition stand: BpuR = Brandon’s PUR protein

Excerpt from Brandon Jutras’ dissertation notebook. He gave an alternative interpretation of the name of the BpuR protein that he functionally defined: Brandon’s PUR

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 19/08/2026

These are probably supposed to be Helicobacter & Vibrio, but I am pretending that spirochetes were not overlooked

zoomed screenshot of MMPC T-shirt, showing curved "bacteria"

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 19/08/2026

They most resemble Helicobacter, but we will pretend that one of these squiggles is a spirochete.

Section of MMPC design, showing some curved bacteria

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 18/08/2026

The ecology of Lyme disease: Long-term data, surprises, and a synthesis "Infection prevalence with zoonotic pathogens ... appeared to arise from the distribution of larval ticks across the entire community of larval hosts." www.pnas.org/doi/10.1073/... #MicroSky

Life cycle of the black-legged tick (I. scapularis), illustrating interactions among ticks, hosts, acorns, and abiotic factors. Tick larvae hatch uninfected with the Lyme bacterium, but can become infected from their hosts during the larval meal (gray shading of larval hosts). Infected nymphs can infect uninfected hosts during the nymphal meal (gray shading of nymphal hosts). Dashed gray lines below the x-axis indicate periods when ticks are alive but not actively questing for hosts. Circled letters correspond to “surprises,” as identified in the text, that have arisen from more than 30 y of study. These surprises conflict with common paradigms which need to be rethought so that we can develop a synthetic understanding of the ecology of tick-borne disease risk.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 11/08/2026

Merging a hobby with my day job. I collect antique microscopes and microscope slides. The mid-to-late-1800s were a golden age of amateur microscopy. Numerous professionals prepared high-quality slides for that large market of hobbyists. "Ixodes from tortoise", prepared ca. 1890.

ca. 1890 microscope slide of a tick taken from a tortoise, and mounted by Ernest Hinton. Next to a magnified image of the tick (3.5x objective, C-mounted digital SLR camera, and transmitted light.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 10/08/2026

ospC diversity in Borrelia burgdorferi: different hosts are different niches A report from 2004 that also found that OspC type U preferentially infected chipmunks academic.oup.com/genetics/art... #MicroSky

Table from the paper.
The outer surface protein C (ospC) locus of the Lyme disease bacterium, Borrelia burgdorferi, is at least
an order of magnitude more variable than other genes in the species. This variation is classified into 22
ospC major groups, 15 of which are found in the northeastern United States. The frequency distributions
of ospC within populations suggest that this locus is under balancing selection. In multiple-niche polymor-
phism, a type of balancing selection, diversity within a population can be maintained when the environment
is heterogeneous and no one genotype has the highest fitness in all environments. Genetically different
individuals within vertebrate species and different vertebrate species constitute diverse environments for
B. burgdorferi. We examined four important host species of B. burgdorferi and found that the strains that
infected each species had different sets of ospC major groups. We found no variation among conspecific
hosts in the ospC major groups of their infecting strains. These results suggest multiple niches create
balancing selection at the ospC locus.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 10/08/2026

Diversity and host specificity of Borrelia burgdorferi’s outer surface protein C (ospC) alleles in synanthropic mammals, with a notable ospC allele U absence from mixed infections Does OspC type U preferentially infect chipmunks? And exclude other types? journals.asm.org/doi/epub/10.... #MicroSky

Figure 2
Heatmap showing ospC allele frequencies across host species (T. striatus, eastern chipmunk; S. carolinensis, eastern gray squirrel; Peromyscus, white-footed/deer mice; M. pennsylvanicus, eastern meadow vole; M. musculus, house mouse; M. mephitis, stripped skunk). Higher allele frequencies are redder and lower frequencies are bluer. Human infectious alleles (A, B, I, and K) are italicized and in bold font.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 10/08/2026

Curiouser and curiouser: understanding the intersection of inter- and intra-specific diversity during the Borrelia burgdorferi enzootic cycle and Lyme disease journals.asm.org/doi/10.1128/... #MicroSky

Fig 1 B. burgdorferi enzootic cycle and reservoir competence. (A) The B. burgdorferi enzootic cycle. Larval ticks (Ixodes) acquire B. burgdorferi during feeding on infected vertebrate hosts. These ticks molt to nymphs before feeding on uninfected hosts and transmitting the bacteria. During feeding, adult female ticks can also transmit the bacteria to reservoirs before completing the tick reproductive cycle and producing new, uninfected larval ticks. Reservoir hosts infected during nymphal and adult tick feeding can harbor the bacteria and, in turn, spread B. burgdorferi back into the tick population. (B) Reservoir competence depends on a variety of factors, including abundance of the host, host-tick interactions, and host-B. burgdorferi interactions (7). Additional complexity is added to the system as different hosts may be more or less competent for specific strains of B. burgdorferi (13, 14). Figure illustrated by Patrick Lane—ScEYEnce Studios.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 07/08/2026

A direct, urine-based test to diagnose acute Lyme disease using actively secreted peptidoglycan as a biomarker Exciting new results from @jutraslab.bsky.social www.medrxiv.org/content/10.6... #TheShowMustGoOn #MicroSky

Figure 1.
Monoclonal antibody cocktail specifically detect released Borreliae PG
(A) Each monoclonal antibody (mAb) were incubated with purified, enzyme-digested B. burgdorferi PG (dPG). Immunoprecipitation, coupled with quantitative LCMS, identified high-affinity interactions for four different mAb. Heat map indicates the percent of each muropeptide bound, relative to input control. (B) Cartoon schematic of the muropeptide structure bound by the mAbs in ‘A’. The numbers associated with each muropeptide species indicate enantomers or isobarics present in B. burgdorferi PG. (C) A cocktail of capture and detection mAb pairs is a sensitive approach to detect purified, dPG produced by B. burgdorferi. Values were background subtracted using the absorbance values of a PBS control. (D) The same cocktail of capture and detection mAb pairs provide high affinity binding to released B. burgdorferi PG in spent culture medium. B. burgdorferi were cultured to late-log, cells harvested, spent cultured media filtered (0.2 μm), and titrations were assayed by ELISA. Control reactions included sterile culture media, processed similarly, or the same sterile media spiked with dPG. (E) Lyme Borrelia spp. release PG. Each species was pulse labeled with 5uCi of 3H L-Orn for 2-3 generations, washed, and back-diluted into fresh media. Pre- and post-culture expansion, PG was purified and quantified by liquid scintillation. (F) The mAb cocktail cross-reacts with digested PG from different Lyme-disease causing Borrelia spp. Purified, dPG, attained from different Borrelia spp. was titrated into human urine (diluted 1:2 with PBS) and detected by ELISA. Values were background subtracted using the absorbance of a neat human urine diluted with PBS (1:2) that was not spiked with PG. Data points with absorbance of 4 were beyond the detection limit of the spectrophotometer.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 04/08/2026

Midwest Microbial Pathogenesis Conference (MMPC) September 25-27, 2026 University of Minnesota Minneapolis, MN Register now! #MicroSky

MMPC Tshirt design. Shows the shape of Minnesota, composed of bacteria and viruses

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 29/07/2026

Devastated to report that Brandon Jutras passed away a day or two ago. Brandon earned his PhD with me. He went on to be an Associate Professor at Northwestern University School of Medicine and a super star in Lyme research. A loving husband and father, a sincere friend, and a brilliant scientist 💔

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 28/07/2026

Relapsing fever in Texas, USA Human Exposure to Spirochete-Infected Ornithodoros turicata in a Residential Setting in the Austin, Texas Metropolitan Area pubmed.ncbi.nlm.nih.gov/42517151/ #MicroSky

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 17/07/2026

On the top of the University’s daily propaganda email ! uknow.uky.edu/research/res...

Screenshot of 7/17 UK Now, the daily propaganda email from the University of Kentucky. Shows an attractive, bearded scientist who is holding up a tick.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 10/07/2026

Today we say goodbye to my parents’ mortal remains ❤️❤️

Two people kissing, within a large frame

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 06/07/2026

Bought this bag of dried milk when I started my lab in 1998 (saved startup funds by buying generic). Finished it in 2024.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 01/07/2026

Riboflavin Salvage Supports Glycolysis in Borrelia burgdorferi Through Flavin-Dependent NAD+ Regeneration Nifty new information from Mollie Jewett and team! onlinelibrary.wiley.com/doi/10.1111/... #MicroSky

Graphical Abstract

The Lyme disease agent Borrelia burgdorferi has limited metabolic capabilities and depends on salvage of riboflavin via the BB0316-BB0319 transport system for generation of critical flavin cofactors FMN and FAD. Riboflavin is important for NAD+ regeneration to fuel glycolysis. FAD-dependent coenzyme A disulfide reductase (CoADR) is the critical link between riboflavin availability and glycolytic redox balance driving glycolytic success in B. burgdorferi.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 01/07/2026

Friendly reminder to use photographs of Ixodes ticks when discussing Lyme disease. The illustrated Dermacentor spp. cannot vector Lyme disease 🤦🙄

Screen cap of U Nomi's opening page on Lyme disease. Shows a Dermacentor spp. tick, which cannot vector Lyme disease

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 24/06/2026

Dr. Mark Martin's "Matters Microbial" podcasts @markowenmartin.bsky.social Watch 'em all! www.youtube.com/playlist?lis... #MicroSky

Screenshot of intro to "Matters Microbial"

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 24/06/2026

The host calcium system contributes to intracellular Rickettsia pathogenesis "Calcium channel blockers (disrupt) rickettsial actin polymerization, and these results highlight the complex interdependence of Rickettsia and host cell biology." journals.asm.org/doi/10.1128/... #MicroSky

Figure 5 from the article:
CCB disruption of actin-based mobility. (A) Fluorescence micrographs of R. conorii and host actin after 48 hours of infection with noted compounds added for the last 24 hours of infection. R. conorii (green) containing actin tails (red) are readily observed in mock (DMSO) treated cells, but the frequency of actin polymerization is reduced in CCB and Cytochalasin D treated cells. (B) Quantification of R. parkeri with observable actin tails after 48 hours of infection of EA.hy926 cells with noted compounds. Treatment with all three CCBs and the actin polymerization inhibitor Cytochalasin D all significantly reduced rickettsial actin polymerization. (C) Similar analysis of actin polymerization in R. conorii-infected EA.hy926 cells. Scale bar = 20 µm. *P < 0.05 by one-way ANOVA with Dunnett’s multiple comparisons test.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 22/06/2026

Machine learning-driven identification of virulence determinants in Borrelia burgdorferi associated with human dissemination New publication from @brissettelab.bsky.social journals.plos.org/ploscompbiol... #MicroSky

Fig 1. Overview of machine learning workflow.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 22/06/2026

Structural architecture of a hybrid β-barrel assembly machinery BAM-TAM complex in Borrelia burgdorferi More cool structural information of the Lyme disease spirochete, from Kalvis Brangulis! www.sciencedirect.com/science/arti... #MicroSky

From the paper:

Figure 1. (A) Structure of the E. coli BAM complex (PDB ID: 9HG9) showing BamA (grey), BamB (orange), BamD (brown), BamC (green) and BamE (purple). (B) AlphaFold-predicted structure of B. burgdorferi BamA (residues 25-821; average predicted local-distance difference test (pLDDT) value of 86.1) superimposed with BamA from E. coli (Uniprot: P0A940; gold; average pLDDT 92.5; Cα root-mean-square deviation (RMSD) of 3.5 Å). Both proteins are illustrated without the N-terminal signal sequence, and the 16-stranded β-barrel of B. burgdorferi BamA is colored grey, while the periplasmic POTRA domains are colored as follows: POTRA1 (residues 28-102), red; POTRA2 (residues 103-180), green; POTRA3 (residues 181-275), blue; POTRA4 (residues 276-353), purple; and POTRA5 (residues 354-430), orange. (C) Superimposed B. burgdorferi POTRA domains 1-5 (RMSD 1.63 to 3.05 Å).

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 15/06/2026

Infection with multiple strains of the Lyme disease bacterium in female mice can affect the strain-specific maternal antibody response in their offspring www.sciencedirect.com/science/arti... #MicroSky

From the publication:
Fig. 2. Experimental design of the study. At 7 weeks of age, 32 female mice were randomly assigned to one of four groups (n = 8 mice per group): (1) uninfected (white), (2) infected with B. burgdorferi strain A (red), (3) infected with B. burgdorferi strain I (blue), and (4) co-infected with both strains (purple). Female mice were infected via nymphal tick bite; uninfected females were infested with uninfected nymphs. At 10 weeks of age and at 3 weeks post-infection, female mice were mated with uninfected male mice. At 13-14 weeks of age and at 6-7 weeks post-infection, female mice produced 139 offspring. At weeks 1 and 2 of age, mouse pups were euthanized (n = 47), exsanguinated, and milk was obtained from their stomachs. A total of 88 offspring were weaned and were assigned to group 1 (G1; n = 45 offspring) and group 2 (G2; n = 43 offspring). The G1 pups and G2 pups were challenged with both B. burgdorferi strains via nymphal tick bite at 6 weeks of age and at 11 weeks of age, respectively.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 14/06/2026

To Move or Not to Move: When and How Bacteria Suppress Flagellar Motility onlinelibrary.wiley.com/doi/full/10.... #MicroSky

Graphical Abstract

Motility cessation in bacteria is a key regulatory strategy that provides multiple survival advantages including enhanced community cooperation, niche adaptation and evasion of host immune responses. This process is controlled by associated mechanisms such as post-translational modifications and second messenger signalling that stabilise non-motile bacterial attachment. This review aims to provide a comprehensive overview of the molecular mechanisms in motility suppression and the functional and environmental conditions that trigger the transition from motile to non-motile states.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 13/06/2026

Wash cycle complete! At the Institute for Cancer Research / Royal Marsden Hospital with @generoom.bsky.social

Two sciency-guys standing next to a multimillion dollar washing machine.
(Actually, a high throughput DNA sequencer)

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 12/06/2026

When Clades Collide: Genomic Admixture in Blacklegged Ticks (Ixodes scapularis) from the Great Plains "~50% infection rate (of B. burgdorferi) in ticks from Iowa and northeastern Nebraska, whereas ticks from Kansas show no evidence of B. burgdorferi infection" www.biorxiv.org/content/10.6...

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 11/06/2026

Borrelia host adaptation Regulator (BadR) regulates rpoS to modulate host adaptation and virulence factors in Borrelia burgdorferi Miller, Karna, and Seshu onlinelibrary.wiley.com/doi/10.1111/... #MicroSky

Model from the paper (current data suggest that this is probably not completely accurate)
Figure 8
BadR represses rpoS to regulate host-specific adaptation in B. burgdorferi. The rpoS gene is upregulated in a badR-deficient B. burgdorferi strain. Log2 fold change of rpoS derived from two microarrays from (pH 7.6/32°C) grown cultures. P-values from pooled (overall) and individual arrays (Rep.1, Rep.2) are indicated using n = 4 for both A3 (WT) and badR− (A). Quantitative RT-PCR fold changes of rpoS are indicated with P ≤ 0.01. Error bars indicate s.e.m. (B). Predicted BadR regulatory network. Many activators of rpoS have been identified (e.g. DsrABb, BosR, RpoN, RpoD, CsrABb). Our study is the first to demonstrate BadR as a repressor of rpoS and thus may facilitate the spirochaete's transition back into ticks. A model for BadR regulation entails the following: 1.) BadR binds upstream of rpoS to repress rpoS in unfed ticks; 2.) Since ROK regulators are nutrient-responsive, BadR regulation may be modulated directly or indirectly by nutrient inducers; 3.) Nutrient surges from the blood meal may provide the inducer to allow BadR's derepression of rpoS; and 4.) BadR regulates chitobiose utilization genes and may activate genes to enhance the spirochaetes maintenance in ticks (lp28-4 genes). Square = activation, oval = repression by BadR respectively (C).

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 08/06/2026

On Borrelia burgdorferi lipids: A lipid compendium of a metabolically compromised bacterium provides insights into lipid acquisition, biosynthesis, and metabolism www.biorxiv.org/content/10.6... #MicroSky

From the Preprint:
Fig. 2. Neutral lipids in B. burgdorferi. (A, B) Sankey diagrams illustrating
the relative abundance of neutral lipids identified via tandem mass
spectrometry. The width of each flow is proportional to the integrated peak area under the curve of the daughter ion, with the distribution of
cholesteryl esters (ChE, A) and triglycerides (TG, B). (C, D) Widefield
epifluorescence microscopy images of fixed B. burgdorferi cells show
lipid staining with either the neutral lipid-specific LipidTOXTM (C) or the
non-specific dye Nile Red (D). Scale bar = 5 μm

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 11/05/2026

The wild, wild west of plasmids: First insights into comparative genomics of Borrelia burgdorferi sensu lato journals.plos.org/plosone/arti... pubmed.ncbi.nlm.nih.gov/42102105/ #MicroSky

Fig 1. Maximum likelihood tree of the 86 genomes based on cgMLST and plasmid presence/absence matrix. Figure includes information about species, reservoir host, tick vector, pathogenicity and genome elements. Species are listed and colored in different colors. Reservoir hosts are shown as icons; unknown hosts are indicated by “?”; for insectivores and carnivores a hedgehog icon is used. Tick vector species are listed. Pathogenicity is shown in different colors (green: nonpathogenic, red: pathogenic, red and “?”: potentially pathogenic, white and “?”: unknown). Genome elements (chromosome and plasmids): presence is indicated in green (complete genome element) and red (incomplete genome element), absence is indicated in grey; “X”: fusion plasmid, “-”: linear plasmid that carry a PFam32 that is typically found on a circular plasmid, “O”: circular plasmid that carry a PFam32 that is typically found on a linear plasmid. “$”: cp32-28-4 (circular plasmid with syntenic gene contents to cp32 plasmid family but encodes a lp28−4 type PFam32 protein), “^”: inverted repeat plasmid, “~”: dimer fusion, “+”: sequence was additionally added, “2”: two cp9 plasmids with different PFam57 proteins. “(X)”: the same cp32−11 type PFam32 was found on a non-fused plasmid (cp32−11) and on a fusion plasmid (cp32−9 + 11); “!”: plasmid name used in this study differs to the published plasmid name (S3 Table). S2 Fig adds information about the continent, vls/vlsE located plasmid, fusion plasmids, and shows reservoir host and vector not as icons, but in separate color-coded columns. S1 Table presents this information in tabular form with additional information on plasmid length.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 06/05/2026

Genomic and structural analysis of major antigenic proteins' variability in the human relapsing fever spirochete Borrelia persica Insights on Vmp/Vlp/Vsp structures and diversity www.sciencedirect.com/science/arti... pubmed.ncbi.nlm.nih.gov/42065078/ #MicroSky

Fig. 8. Predicted 3rd dimensional structure of B. persica LMU-C01 Vmp proteins. One representative from each Vlp subfamily (A, alpha; B, beta; C, gamma; D, delta) and the Vsp protein (E) are presented. Protein structures were modeled using AlphaFold (v1.5.2) and visualized using ChimeraX (v1.9). Membrane orientation and surface rendering were modeled using PPM database. Different colors correspond to the pLDDT score (dark blue, very high pLDDT>90; light blue, high 70<pLDDT<90; yellow, moderate 70>pLDDT>50; orange, low pLDDT<50). The membrane attachment properties of the Vsp (F) and a Vlp representative (G) are shown. The two-colored plates represent the double layered bacterial membrane where the blue plate corresponds to the outer membrane. Hydrophobic properties of the Vmp proteins represented by Vlp alpha protein are presented on the surface structure of the protein (H). Light blue represents hydrophilic residues, whereas yellow color represents hydrophobic residues.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 01/05/2026

The lab is 28 years old today! Thank you to everyone with whom I have had the privilege to work! This has been an exciting ride, and I look forward to many more cool discoveries and adventures!

Stevenson lab personnel through the years, photographed in various exotic locations

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 21/04/2026

Innate immune responses to Borrelia burgdorferi during tick-feeding: mechanistic insights relevant to Lyme disease cool new report from Kundu, Joyner, and Gomes-Solecki journals.asm.org/doi/pdf/10.1... #MicroSky

FIG 9 Model of murine host immune responses to Bb, tick factors, and tick-transmitted Bb relative to the control. Graphical summary of the study showing the infection conditions—subcutaneous needle inoculation of multi-strain Bb (BbSC), uninfected tick feeding (Tick–Bb), and multi-strain Bb-infected tick feeding (Tick+Bb)—in C3H/HeN mice, with sequential analyses, including flow-cytometric profiling of immune cell populations at the bite/inoculation site and in spleen, and serum proteome profiling to quantify 19 cytokines and 20 chemokines.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 17/04/2026

From forest floor to doctor’s office: the immunological journey of Borrelia burgdorferi through vertebrate hosts new review by Singh & Bankhead www.frontiersin.org/journals/imm... #MicroSky

Figure 3 from the article:
Scenic stops and extended stay: immune interference across the host landscape shapes tissue colonization, persistence, and clinical manifestation during B. burgdorferi infection. This schematic integrates pathogen-intrinsic strategies and host immune disruptions across spatial, temporal, and immunological scales. It frames the journey from early tissue colonization to prolonged immune stalemate. The central panel depicts the host landscape, emphasizing the translational continuum between experimental host models and human disease. Surrounding concentric rings organize immune interference by function rather than by individual molecules. The inner pink ring delineates four major modes of host-pathogen interaction that shape immune interference and persistence. The outer ring depicts representative mechanisms corresponding to each immune-interference category, illustrated as discrete modules.

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 07/04/2026

In honor of the Artemis II mission, photos of the full Moon that were taken during the 1850s by Warren de LaRue. Two slightly different images were made into a stereoscopic view, to give a 3-D effect.

Illuminated stereoview of the Moon, showing both Moon images

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Brian Stevenson Ph.D. spirochete lab @bstevensonlab.bsky.social · 02/04/2026

Lyme Borreliosis Nature Reviews Disease Primers pubmed.ncbi.nlm.nih.gov/41888159/ #MicroSky #TickSky

The Ixodes ricinus complex life cycle comprises four life stages (egg, larva, nymph and adult), where each post-egg stage needs a blood meal to develop into the next stage or reproduce. Larvae and nymphs feed on many vertebrate species, including mammals, songbirds and lizards, whereas adults feed on a narrower range of hosts, most commonly deer. Lyme borreliae are not passed from infected female ticks to their offspring; thus, the bacteria are maintained in an enzootic cycle between immature ticks (larvae and nymphs) and reservoir hosts, typically small mammals and songbirds.
For illustrative purposes, this figure typifies the life cycle of Ixodes scapularis in the northeastern USA. Eggs are laid in the late spring; larvae will hatch in mid-summer and then seek their first host in late summer. Engorged larvae will detach, drop off the host and moult into nymphs. Unfed nymphs emerge and quest for their second host the following late spring through summer, which is therefore the epidemiologically most risky time of the year. Engorged nymphs detach, drop off the host and moult into adults in the leaf litter. Beginning in the fall, adult ticks quest for a third host, most commonly deer. Engorged females detach from the host and drop into the leaf litter, where they overwinter. Adult ticks that are unable to locate hosts in the fall will also overwinter and resume questing in early spring. Fed I. scapularis females will oviposit an egg mass (up to 1,500–2,000 eggs), and then die. Although both nymphs and adult females may be infected, because of their small size (about the size of a poppy seed), their large numbers, and a spring/summer activity period that coincides with increased outdoor human activity, nymphs are responsible for most human infections. Because they are larger (about the size of a sesame seed) and have red coloration, adult female ticks are easier to notice and remove before the bacteria can be transmitted

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