Biomedical subjects

Jonathan Barasch

Publications and source records attributed to Jonathan Barasch.

3 recordsLinked to original sources

PubMed2026

Inherited Susceptibility to Urinary Tract Infections from Kidney Papilla to Bladder.

Urinary tract infections (UTIs) are traditionally viewed as environmentally driven, yet their inherited susceptibility remains largely unexplored. We conducted a cross-biobank genome-wide association study of recurrent UTIs in 1,860,836 individuals (213,869 cases and 1,646,967 controls). We identified 36 genetic susceptibility loci and performed tissue-based multi-omic mapping to prioritize candidate causal genes. UTI risk alleles preferentially modulated epithelial gene expression in kidney and bladder, converging on urinary epithelia structure and function. PSCA, encoding a secreted epithelial surface protein, emerged as the strongest candidate under genetic control; the gene product is constitutively secreted into the urine from kidney papilla and bladder epithelia, binds uropathogenic E. coli, and inhibits bacterial growth in vitro. Our findings define the polygenic architecture of UTIs and highlight the critical role of uroepithelial surface defenses, providing a new framework for host-directed, non-antibiotic interventions.

Journal Article↗

PubMed2026

A posttranslational modification of fimbriae drives pathogenicity in Klebsiella pneumoniae.

Antimicrobial resistance is a severe public health burden. Especially concerning are multidrug resistant (MDR) infections, which restrict treatment options and significantly increase mortality risk. A major cause of MDR infections worldwide is carbapenem-resistant Klebsiella pneumoniae (CRKp). The predominant CRKp sequence type worldwide is ST258. However, the factors underlying ST258's epidemic success are not well defined. Genomic analyses of clinical isolates of CRKp have found that the two-component regulatory system CrrAB is a genomic feature of ST258, suggesting that it may contribute to its global dominance. Despite this, the molecular details underpinning CrrAB's contribution to ST258 Kp biology and pathogenicity are poorly understood. We used RNA-sequencing to identify the regulon of CrrA and found that CrrAB induces the expression of a gene, encoding Crr-regulated fimbriae modifying protein (CfmP), that is essential for pathogenesis driven by this two-component system. We performed mass spectrometry analyses of fimbriae purified from Kp expressing or lacking cfmP and found that CfmP induces a novel oxidation to a histidine residue in the major pilin subunit of fimbriae, FimA. We demonstrate that this oxidation significantly increases host cell adhesion and high bacterial loads within the host. CrrAB also drives high antibiotic resistance in CRKp. Thus, our results place CrrAB at the intersection of pathogenicity and antibiotic resistance supporting its function as an important regulatory system driving the global dominance of ST258.

Klebsiella pneumoniae↗

PubMed2025

Urobiota analysis and genome-wide association study in pediatric recurrent urinary tract infections and vesicoureteral reflux.

Urinary tract infections (UTIs) are the most common severe bacterial infections in young children, often associated with vesicoureteral reflux (VUR). To explore host genetic-microbiota interactions and their clinical implications, we analyzed the urinary microbiota (urobiota) and conducted genome-wide association studies for bacterial abundance traits in pediatric patients with UTI and VUR from the Randomized Intervention for Children with Vesicoureteral Reflux and Careful Urinary Tract Infection Evaluation cohorts. We identified 4 urobiota community types based on relative abundance, characterized by the genera Enterococcus, Prevotella, Pseudomonas, and Escherichia/Shigella, and their associations with VUR, age, and toilet training. Children with VUR exhibited decreased microbial diversity and increased abundance of genera that included opportunistic pathogens, suggesting a disrupted urobiota. We detected genome-wide significant genetic associations with urinary bacterial relative abundances, in or near candidate genes including CXCL12, ABCC1, and ROBO1, which are implicated in urinary tract development and response to infection. We showed that Cxcl12 was induced 12 hours after uropathogenic bacterial infection in mouse bladder. The association with CXCL12 suggests a genetic link between UTI, VUR, and cardiovascular phenotypes later in life. These findings provide the first characterization to our knowledge of host genetic influences on the pediatric urobiota in UTI and VUR, offering insights into the interplay between disease, host genetics, and the urobiota composition.

Urinary Tract Infections↗