Molecular detection of Tropheryma whipplei DNA: a crucial tool for diagnosing Whipple's disease in the brain. Illustrative caseUaliyeva, Basu, Roguski
et alJ Neurosurg Case Lessons (2025) 9 (12)
Abstract: Whipple's disease is a rare chronic infectious disorder caused by the bacterium Tropheryma whipplei. It commonly involves the small intestine and presents with chronic diarrhea, abdominal pain, weight loss, enlarged lymph nodes, and migratory polyarthralgia, with involvement of the CNS.The authors describe the case of a 69-year-old male who presented with arthritis on immunomodulatory treatment, weight loss, confusion, worsening memory, and right-sided weakness. MRI of the brain revealed a 2.4-cm enhancing mass in the left lentiform nucleus. A stereotactic biopsy was performed, with pathology demonstrating granulomatous inflammation with reactive astrocytes. Broad-range polymerase chain reaction and next-generation sequencing of the tissue detected T. whipplei DNA. Intravenous ceftriaxone yielded no clinical improvement.Whipple's disease should be considered in an immunosuppressed patient presenting with progressive cognitive decline, weight loss, and imaging findings that are atypical for a neoplasm. Whipple's disease can be diagnosed by histological identification of the organism or by the presence of foamy macrophages containing gram-positive bacilli in the biopsy of the small intestine or affected tissues. Its diagnosis can be challenging as T. whipplei grows inconsistently in culture and can rapidly become undetectable with antibiotic therapy. Molecular detection might be required to improve diagnostic accuracy. https://thejns.org/doi/10.3171/CASE24687.
A Robust Strategy for Introducing Amino-Modifiers in Nucleic Acids: Enabling Novel Amino Tandem Oligonucleotide Synthesis in DNA and RNASaraya, Horton, Sammons
et alChemistry (2025)
Abstract: Amino-modifiers are pivotal chemical modifications in nucleic acid scaffolds, serving applications ranging from (bio)conjugation to probing the origins of life. We report a simple, efficient, and cost-effective methodology for the introduction of amino-modifiers into DNA and RNA. This approach leverages a commercially available sulfonyl-containing solid support, which is first converted into a mixed N-hydroxysuccinimide carbonate, enabling robust conjugation with primary and secondary amines whether nucleosidic or non-nucleosidic. Oligonucleotides are synthesized via solid-phase synthesis and purified using standard methods, with little to no modification. Building on this framework, we introduce a novel amino-containing tandem oligonucleotide synthesis (aTOS) methodology, which facilitates the introduction of multiple terminal amino (or monophosphate) groups across two oligonucleotide strands. This innovative method broadens the toolkit for the introduction of amino modifications in nucleic acids, for applications in nucleic acid (bio)chemistry and biotechnology.© 2025 Wiley‐VCH GmbH.
Large-scale combination screens reveal small-molecule sensitization of antibiotic-resistant gram-negative ESKAPE pathogensTse, Zhu, Peters
et alProc Natl Acad Sci U S A (2025) 122 (13), e2402017122
Abstract: Antibiotic resistance, especially in multidrug-resistant ESKAPE pathogens, remains a worldwide problem. Combination antimicrobial therapies may be an important strategy to overcome resistance and broaden the spectrum of existing antibiotics. However, this strategy is limited by the ability to efficiently screen large combinatorial chemical spaces. Here, we deployed a high-throughput combinatorial screening platform, DropArray, to evaluate the interactions of over 30,000 compounds with up to 22 antibiotics and 6 strains of gram-negative ESKAPE pathogens, totaling to over 1.3 million unique strain-antibiotic-compound combinations. In this dataset, compounds more frequently exhibited synergy with known antibiotics than single-agent activity. We identified a compound, P2-56, and developed a more potent analog, P2-56-3, which potentiated rifampin (RIF) against antibiotic-resistant strains of Acinetobacter baumannii and Klebsiella pneumoniae. Using phenotypic assays, we showed P2-56-3 disrupts the outer membrane of A. baumannii. To identify pathways involved in the mechanism of synergy between P2-56-3 and RIF, we performed genetic screens in A. baumannii. CRISPRi-induced partial depletion of lipooligosaccharide transport genes (lptA-D, lptFG) resulted in hypersensitivity to P2-56-3/RIF treatment, demonstrating the genetic dependency of P2-56-3 activity and RIF sensitization on lpt genes in A. baumannii. Consistent with outer membrane homeostasis being an important determinant of P2-56-3/RIF tolerance, knockout of maintenance of lipid asymmetry complex genes and overexpression of certain resistance-nodulation-division efflux pumps-a phenotype associated with multidrug-resistance-resulted in hypersensitivity to P2-56-3. These findings demonstrate the immense scale of phenotypic antibiotic combination screens using DropArray and the potential for such approaches to discover new small molecule synergies against multidrug-resistant ESKAPE strains.
Adaptive ATP-induced molecular condensation in membranized protocellsMukwaya, Yu, Yang
et alProc Natl Acad Sci U S A (2025) 122 (13), e2419507122
Abstract: Liquid-liquid phase separation (LLPS) has been achieved in various cytomimetic (protocell) models, but controlling molecular condensation using noninert crowders to systematically alter protocell function remains challenging. Intracellular ATP levels influence protein-protein interactions, and dysregulation of ATP can alter cellular crowding dynamics, thereby disrupting the normal formation or dissolution of condensates. Here, we develop a membranized protocell model capable of endogenous LLPS and liquid-gel-like phase separation through precise manipulation of intermolecular interactions within semipermeable polysaccharide-based microcapsules (polysaccharidosomes, P-somes), prepared using microtemplate-guided assembly. We demonstrate that intraprotocellular diffusion-mediated LLPS can be extended into the liquid-gel-like domain by the uptake of the biologically active crowder ATP, resulting in a range of modalities dependent on the fine-tuning of molecular condensation. Endogenous enzyme activity in these crowded polysaccharidosomes is enhanced compared to free enzymes in solution, though this enhancement diminishes at higher levels of intraprotocellular condensation. Additionally, increased molecular crowding inhibits intraprotocell DNA strand displacement reactions. Our findings introduce an expedient and optimized approach to the batch construction of membranized protocell models with controllable molecular crowding and functional diversity. Our mix-incubate-wash protocol for inducing endogenous LLPS in membranized protocells offers potential applications in microreactor technology, environmental sensing, and the delivery and sustained release of therapeutics.
膜杰作
Star Staining
