Brian Stevenson Ph.D. spirochete lab
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bstevensonlab.bsky.social
Brian Stevenson Ph.D. spirochete lab
@bstevensonlab.bsky.social
3K followers 2K following 740 posts
Mostly about bacterial gene/protein regulation & function, esp. with Borrelia burgdorferi and Lyme disease. Professor at U Kentucky, views are my own. He/him
Lab= http://microscopist.net/Stevenson_Lab.html
UK= https://medicine.uky.edu/users/bstev0
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bstevensonlab.bsky.social
My Granddad, William Robert Fleming Stevenson, received these medals (and shrapnel in his knee) for 4 years in the European trenches, fighting The War to End All Wars.
#VeteransDay
#RemembranceDay
World War 1 medals superimposed over a field of red poppies
November 11, 2025 at 12:09 PM
bstevensonlab.bsky.social
The answer may not be at the bottom of a margarita glass, but we should at least check
November 7, 2025 at 10:26 PM
bstevensonlab.bsky.social
Gac Is a Transcriptional Repressor of the Lyme Disease Spirochete's OspC Virulence-Associated Surface Protein

Castro-Padovani, Saylor, Husted, Krusenstjerna, Jusufovic, and Stevenson
2023, J Bacteriol, 205:e0044022.
doi: 10.1128/jb.00440-22
pubmed.ncbi.nlm.nih.gov/36920207/
#MicroSky
(A) Electrophoretic mobility shift assay (EMSA) of labeled Ip89 ospC operator, without (−) and with (+) cytoplasmic extract from strain B31. The asterisk indicates shifted probe that was present only when borrelial extract was included, indicating presence of a DNA-binding component. Unbound DNA is indicated by “free.” Some labeled DNA probe remained in the wells of the gel. (B) Cytoplasmic extract from strain B31 was incubated with Ip89 ospC operator DNA affixed to beads, eluted with increasing concentrations of NaCl, and eluates were separated by SDS-polyacrylamide gel electrophoresis. Lanes are labeled with the concentration of NaCl used for that elution. The arrow indicated a protein band of 30 to 35 kDa that eluted in the 0.3 and 0.5 mM NaCl washes. (C) Amino acid sequence of GyrA and Gac (the two potential initiation methionines of Gac are indicated by boldface and underlining). Mass spectrometry identified nine unique peptides that all mapped to the Gac ORF. Peptides identified with high confidence are shaded green, and those with lower confidence are red. (D) Predicted structures of B. burgdorferi Gac and GyrA proteins, as determined by AlphaFold (https://alphafold.ebi.ac.uk). Both are consistent with the solved structures of B. burgdorferi Gac and the N-terminal domain of E. coli GyrA (https://www.rcsb.org/structure/4ckk).
November 7, 2025 at 3:51 PM
bstevensonlab.bsky.social
Quantitative analyses of interactions between SpoVG and RNA/DNA
Saylor et al, 2023, Biochem Biophys Res Commun, 30:654:40-46.
doi: 10.1016/j.bbrc.2023.02.044
pubmed.ncbi.nlm.nih.gov/36889033/
#MicroSky
Ribbon diagram of SpoVG dimer structure
November 7, 2025 at 3:47 PM
bstevensonlab.bsky.social
Congratulations to Tim Saylor for successfully defending his MS thesis!
After my trainees complete their defense, I give them a custom-engraved julep cup, then we share a drink together 🥃
Recent graduate with pewter julep cup
November 7, 2025 at 3:42 PM
bstevensonlab.bsky.social
On interactions between Midichloria and Borrelia in Ixodes ricinus ticks: a multifaceted phenomenon likely driven by molecular mechanisms that regulate tick feeding, modulate host immunity, and provide nutritional support.

www.clinicalkey.com#!/content/pl...

#MicroSky
#TickSky
Figure from article: An overview of the shikimate pathway and genomic distribution of genes encoding enzymes required for chorismate biosynthesis among vertically and horizontally transmitted tick-associated symbionts and pathogens. The shikimate pathway comprises seven enzymatic reactions that convert PEP and E4P into chorismate, a key metabolic intermediate that serves as the precursor for the aromatic amino acids tryptophan, tyrosine, and phenylalanine. This pathway is found in various bacteria, archaea, fungi, algae, protozoans, and plants, but is absent in animals. Genes encoding the enzymes required for chorismate biosynthesis are indicated in brackets in the left panel. Among vertically and horizontally transmitted bacteria associated with ticks, only the genomes of Coxiella and Francisella endosymbionts contain a complete or nearly complete set of shikimate pathway genes necessary for chorismate production. Whole-genome sequences of the most important symbiotic and pathogenic bacteria associated with ticks were retrieved from the NCBI database i and included in the analysis. Abbreviations: CS, chorismate synthase; DAHP, 3-deoxy-D-arabino-heptulosonate-7-phosphate; DAHPS, DAHP synthase; DHQD, 3-dehydroquinate dehydratase; DHQS, 3-dehydroquinate synthase; E4P, erythrose-4-phosphate; EPSP, 5-enolpyruvylshikimate-3-phosphate; EPSPS, EPSP synthase; LB, Lyme borreliosis; PEP, phosphoenolpyruvate; RF, relapsing fever; SDH, shikimate dehydrogenase; SK, shikimate kinase.
October 31, 2025 at 6:48 PM
bstevensonlab.bsky.social
For those who are wondering about grant proposal reviews in the USA
Dear NIH Peer Reviewer, You are receiving this email because you are listed on an NIH peer-review meeting roster scheduled to begin in the coming weeks. As you surely know, NIH has not been appropriated funds with which to operate. SROs cannot work, cannot prepare for meetings, respond to your emails, etc. However, the NIH computer systems that support review functions are still available to reviewers (though without technical support) and we ask that you continue your preparations for upcoming review meetings as best you can. If it becomes clear that your meeting must be postponed, you will receive an email to that effect. Please do not join any meeting if it is scheduled to start on a day when the government is shutdown. After funding is appropriated and NIH operations resume, we will be in touch. CSR will make every effort to review all applications originally slated to be reviewed this round. Thank you for your contributions to the NIH peer review process. Regards,
October 21, 2025 at 12:27 PM
bstevensonlab.bsky.social
We were visited a couple of weeks ago by Dr. Tomasz Bykowski and his family, on vacation around the US from their home in Warsaw, Poland.
Tomek was a postdoc in our lab from 2004-2007, and is currently Director of Strategy and Development of Horus and Member of the Supervisory Board of Genomed SA
Brian Stevenson and Tomasz Bykowski
October 14, 2025 at 4:32 PM
bstevensonlab.bsky.social
Lab alumna Dr. Jen Miller, presenting today at ILADS conference. Jen is currently Vice President of Clinical and Scientific Operations at Galaxy Diagnostics. She was my second PhD student.
Photograph of projector screen, showing photograph of Dr Jen Miller and title of her talk: "Survival of the fittest - how vector-borne pathogens evade teh immune system (and what to do about it)"
October 13, 2025 at 1:57 PM
bstevensonlab.bsky.social
On the way to Midwest Microbial Pathogenesis Conference 2025, in St Charles, Illinois!
Hosted by Loyola University Chicago
#MMPC2025
#MicroSky

www.mmpconference2025.com
Announcing MMPC 2025
October 3, 2025 at 4:01 PM
bstevensonlab.bsky.social
Antigenic variation is caused by long plasmid segment conversion in a hard tick-borne relapsing fever Borrelia miyamotoi

important new paper by Takeuchi, Gotoh, Hayashi, Kawabata, and Takano

journals.plos.org/plospathogen...

#MicroSky
From the publication: Fig 7. The mechanism to change the expression vmp cassette in B. miyamotoi. The expression vmp cassette on the lp4 plasmid is altered by the conversion of the expression locus segment, in which the expression locus segment is replaced by a duplicated segment of other plasmids carrying the cluster of archival silent cassettes (lp5, lp6, and lp10.1). The replacing segment starts from one of the silent cassette and ends at the right end of the plasmid; thus the first silent cassette on the replacing segment is expressed after conversion. As the lengths of the replacing segment are variable (ranged from 6.9 kb to 15.3 kb in the reisolates analyzed in this study), leading to the change in the length of lp4. Although the molecular mechanism underlying the conversion of the expression locus segment is not known, it appears that the clustering of vmp cassettes and their tail-to-head cassette organization in each cluster allow the effective switching of the expression vmp cassette by the conversion of long plasmid segment. Notable structural features of vmp-encoding plasmids and vmp cassettes on these plasmids are the sequence conservation of the right ends of the lp4, lp5, lp6, and lp10.1 plasmids and the presence of UHS-like sequences around the start codon of vmp genes. To understand the molecular mechanism underlying the conversion of the expression locus segment, it will be necessary to analyze the roles of these elements as well as identify the enzyme(s) involving the conversion.
October 1, 2025 at 2:13 PM
bstevensonlab.bsky.social
Sept. 29, 2010
Gala Dinner of the International Conference on Lyme Borreliosis and other Tick-Borne Diseases, Ljubljana, Slovenia
with collaborators Peter Kraiczy & Claudia Hammerschmidt, and lab members Amy Bowman, Brandon Jutras & Cat Brissette
@brissettelab.bsky.social
@jutraslab.bsky.social
At the Gala Dinner of the International Conference on Lyme Borreliosis and other Tick-Borne Diseases, Ljubljana, Slovenia with collaborators Peter Kraiczy & Claudia Hammerschmidt, and lab members Amy Bowman, Brandon Jutras & Cat Brissette
September 29, 2025 at 3:56 PM
bstevensonlab.bsky.social
Submitted yet another grant proposal today, for a foundation, to be reviewed next month.
That’s 5 grant proposals in play for review before year’s end.
Pair of rolling dice Source unknown
September 29, 2025 at 3:24 PM
bstevensonlab.bsky.social
Images from Cutter's 1878 patent application
Cutter's 1878 patent application Image from the patent application
September 28, 2025 at 6:46 PM
bstevensonlab.bsky.social
Cutter's 1878 patented "Box for Vaccine Matter".
For carrying and protecting smallpox scabs, which were to be used for vaccinations.
#MicroSky

images from my collection
Top view of a Cutter's Box for Vaccine Material Bottom view of a Cutter's Box for Vaccine Material Cutter's Box for Vaccine Material measures approximately 7/8 inches , 2.2 cm, in diameter Inside of a Cutter's Box for Vaccine Material
September 28, 2025 at 6:45 PM
bstevensonlab.bsky.social
A break from my usual science posts.
Brilliant rugby today, England dominated Canada 33-13.
Poster of the England Women’s Rugby World Cup team
September 27, 2025 at 5:42 PM
bstevensonlab.bsky.social
I shared this a few days ago:

"Thrill"
The best-ever description of spirochete movement, likening the bacteria's flexing to a shiver down the spine when feeling thrilled.
R.C. Rosenberger, 1908, "The spirochaete found in syphilis", Am J Med Sci
September 24, 2025 at 6:49 PM
bstevensonlab.bsky.social
"Thrill"
The best-ever description of spirochete movement, likening the bacteria's flexing to a shiver down the spine when feeling thrilled.
R.C. Rosenberger, 1908, "The spirochaete found in syphilis", Am J Med Sci

#MicroSky 🦠🧫🔬
Except from 1908 report: "The most common movement described by the parasite was bending of the whole organism backward and forward; or what may be described as quite a marked vibratory thrill."
September 18, 2025 at 4:05 PM
bstevensonlab.bsky.social
Supporting CDC scientists, who were blocked by the government from attending and presenting at the International Conference on Lyme Borreliosis and Other Tick-Borne Diseases.
Button, reads “I love CDC”
September 8, 2025 at 8:59 PM
bstevensonlab.bsky.social
Hello Chicago!

news.mayocliniclabs.com/2025-interna...

#MicroSky
Emblem for 2025 International Conference on Lyme Borreliosis
September 7, 2025 at 8:42 PM
bstevensonlab.bsky.social
Microphotograph slide of two men and a Ross-type microscope.
By the early 1850s, photography had developed to the point that fine-grain emulsions could be applied to glass slides, then photographs taken through a microscope. These novelties were the forerunners of microfilm
Microphotograph slide of two men and a Ross-type microscope
September 5, 2025 at 12:15 PM
bstevensonlab.bsky.social
Saw this photo of Adah Elizabeth Verder (1900-1997) in another post, accompanied by comments on mouth pipeting. When I took intro microbiology in 1979, one of the first lessons in lab was mouth pipeting technique. Pay attention, and it was the most accurate, fastest method available.
#MicroSky
Adah Elizabeth Verder (1900-1997) using the mouth pipeting technique
August 30, 2025 at 10:55 AM
bstevensonlab.bsky.social
photograph of Willy Burgdorfer
August 25, 2025 at 2:31 PM
bstevensonlab.bsky.social
Comic regarding a smart automatic pipet. Person explains that the pipet’s purpose is just to pipet. The pipet complains that it is no better than an undergrad
August 25, 2025 at 12:06 PM
bstevensonlab.bsky.social
Black swallowtail caterpillars in our herb garden. IMHO the most important reason to grow parsley. Debbie disagrees, but is willing to accept them in light of what they will become.
Swallowtail caterpillars on parsley plants Swallowtail caterpillar on parsley plants
August 16, 2025 at 2:50 PM