Selected Grantee Publications
Whole-Genome Sequences of Six Borrelia recurrentis Strains Obtained via PacBio Sequencing
Gaber et al., Microbiology Resource Announcements. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11895452
The spirochetal bacterium Borrelia recurrentis causes louse-borne relapsing fever (LBRF), which leads to significant morbidity and mortality in several African countries. Previous sequencing studies of B. recurrentis demonstrated discrepancies and did not accurately define the antigenic variation system. In this study, researchers used long-read PacBio technology to conduct whole-genome sequencing of six B. recurrentis strains that had been isolated from LBRF patients earlier. The resulting sequences of each genome included one linear chromosome and five linear plasmids, whose average size was 1,284,895 bp, with the mean GC content being 27.5%. Supported by ORIP (T32OD011083) and NIAID.
Antimicrobial Resistance of Vibrio spp. from the Coastal California System: Discordance Between Genotypic and Phenotypic Patterns
Sebastian et al., Applied and Environmental Microbiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39898660
Vibriosis, infection with non-cholera Vibrio spp., is the most common seafood-borne illness globally, with major impacts on public health, food security, and wildlife health. Potential treatments for antimicrobial-resistant Vibrio spp. in humans, aquaculture, and marine wildlife are complicated by current diagnostic challenges regarding bacterial species identification and interpretation of antimicrobial resistance patterns. Researchers sequenced 489 Vibrio spp. isolates, and antibiotic susceptibility testing was performed to compare the presence of resistance genes with phenotypes. Results determined that the presence of ß-lactamase genes alone in sea otter isolates does not necessarily correlate with an ampicillin-resistant phenotype, likely due to deleterious amino acid substitutions in certain blaCARB alleles. Unexpected detection of previously misidentified Vibrio diabolicus in sea otters suggests that a broader taxonomic group of Vibrio infect sea otters than previously described. Continued monitoring of Vibrio spp. phenotypes and genotypes in sea otters is warranted to observe biologically relevant changes in antimicrobial resistance. Supported by ORIP (T32OD011147).
Quorum Sensing LuxR Proteins VjbR and BabR Jointly Regulate Brucella abortus Survival During Infection
Caudill et al., Journal of Bacteriology. 2025.
https://pubmed.ncbi.nlm.nih.gov/40013834
Brucella abortus is a zoonotic bacterial pathogen that causes brucellosis, a persistent chronic infection that is globally endemic. B. abortus uses quorum sensing to escape immune clearance attempts, regulate virulence, and cause persistent infection within hosts. B. abortus quorum sensing system comprises two LuxR proteins, VjbR and BabR, as well as two signals, dodecanoyl (C12 AHL) and 3-oxododecanoyl (3-OXO-C12 AHL) homoserine lactone. Using chronic infection 6- to 7-week-old C57Bl/6 and BALB/c male and female mouse models, researchers found that the ΔvjbRΔbabR double-deletion strain was attenuated compared with single mutants. These results demonstrate that both quorum sensing proteins, VjbR and BabR, coordinate to maintain survival. This study helps further characterize the Brucella quorum sensing systems and indicates that further attention should be given to the joint interactions between VjbR and BabR in controlling virulence. Supported by ORIP (T32OD028239) and NIAID.
Prostatic Escherichia coli Infection Drives CCR2-Dependent Recruitment of Fibrocytes and Collagen Production
Scharpf et al., Disease Models & Mechanisms. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11789281
In men, lower urinary tract dysfunction (LUTD) is commonly linked to prostatic collagen accumulation through inflammation-mediated mechanisms. Researchers used 8- to 10-week-old male reporter mice, exposed to either sterile phosphate buffered saline (PBS) or Escherichia coli, to identify that circulating Lyz2+S100a4+Gli1+ myeloid-derived cells are recruited to the prostate to drive inflammation and collagen synthesis. Researchers also used 8- to 10-week-old male Ccr2‑/ - null and Ccr2+/- control mice, exposed to either sterile PBS or E. coli, to determine if Ccr2 is necessary for the fibrotic response to prostatic uropathogen infection. Results demonstrated that CCR2+ cells mediate the collagen abundance and fibrotic response to prostate inflammation. This study elucidates the cell types underlying prostate fibrosis and can be utilized to develop targeted therapies. Supported by ORIP (T32OD010957), NCI, NIDDK, and NIEHS.
A Murine Model of Trypanosoma brucei-Induced Myocarditis and Cardiac Dysfunction
Crilly et al., Microbiology Spectrum. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11792545
Trypanosoma brucei is a protozoan parasite that causes human and animal African trypanosomiases, HAT and AAT, respectively. Cardiac symptoms are commonly reported in HAT patients, and intracardiac parasites with accompanying myocarditis have been observed in both natural hosts and animal models for T. brucei infection. A clinically relevant, reproducible murine model for T. brucei–associated cardiomyopathy is currently unavailable. The researchers developed a 7- to 10-week-old C57Bl/6J male and female mouse model for T. brucei infection that demonstrates myocarditis, elevated serum levels of NT-proBNP, and electrocardiographic abnormalities, recapitulating the clinical features of infection. The results demonstrate the importance of interstitial space in T. brucei colonization and provide a relevant, reproducible murine model to investigate the pathogenesis and potential therapeutics of T. brucei-mediated heart damage. Supported by ORIP (T32OD011089, S10OD026859), NCI, and NIA.
Single-Cell Transcriptomics Predict Novel Potential Regulators of Acute Epithelial Restitution in the Ischemia-Injured Intestine
Rose et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39853303
Following ischemia in the small intestine, early barrier restoration relies on epithelial restitution to reseal the physical barrier and prevent sepsis. Pigs share a similar gastrointestinal anatomy, physiology, and microbiota with humans. Researchers used neonatal and juvenile, 2- to 6-week-old male and female Yorkshire cross pigs to determine upstream regulators of restitution. Single-cell sequencing of ischemia-injured epithelial cells demonstrated two sub-phenotypes of absorptive enterocytes, with one subset presenting a restitution phenotype. Colony-stimulating factor-1 (CSF1) was the only predicted upstream regulator expressed in juvenile jejunum compared with neonatal jejunum. An in vitro scratch wound assay using IPEC-J2 cells showed that BLZ945, a colony-stimulating factor 1 receptor antagonist, inhibited restitution. Ex vivo ischemia-injured neonatal pig jejunum treated with exogenous CSF1 displayed increased barrier function. This study could inform future research focused on developing novel therapeutics for intestinal barrier injury in patients. Supported by ORIP (T32OD011130, K01OD028207), NCATS, NICHD, and NIDDK.
Matrikine Stimulation of Equine Synovial Fibroblasts and Chondrocytes Results in an In Vitro Osteoarthritis Phenotype
Gagliardi et al., Journal of Orthopaedic Research. 2025.
https://pubmed.ncbi.nlm.nih.gov/39486895
Advancements in therapy development for osteoarthritis (OA) currently are limited due to a lack of physiologically relevant in vitro models. This study aimed to understand the effect of matrikine stimulation, using human recombinant fibronectin fragment containing domains 7–10 (FN7–10), on equine synovial fibroblasts and chondrocytes. Inflammatory cytokines, chemokines, and matrix degradation genes in equine synovial fibroblasts and chondrocytes were significantly altered in response to FN7–10 stimulation; marked upregulation was observed in interleukin-6 (IL-6), IL-4, IL-10, matrix metalloproteinase 1 (MMP1), MMP3, MMP13, CCL2/MCP1, and CXCL6/GCP-2 gene expression. Only IL-6 protein production was significantly increased in media isolated from cells stimulated with FN7–10. These results support the potential use of equine synovial fibroblasts and chondrocytes—employing FN7–10—as representative in vitro models to study OA. Supported by ORIP (T32OD011130) and NIAMS.