Year: 2025
Type: article
Abstract: Nocardiosis is a serious infection in immunosuppressed patients, especially transplant recipients. The slow-growing phenotype of the bacterium and the variety of symptoms complicate diagnosis and delay antimicrobial therapy, resulting in high mortality rates despite effective treatments. A further complication is that some nocardiosis patients test positive in fungal diagnostics that detect (1,3)-β-D-glucan (the Fungitell assay), but the basis for this cross-reactivity remains unknown. We demonstrate that nocardial cell wall arabinogalactan is a cryptic antigen responsible for cross-reactivity in the Fungitell assay and that this antigen is revealed in vivo following bacterial cell lysis. We further show that the reactivity results from a β-glucose substitution of the galactan domain, a modification specific to nocardia, and identify the optimal antigen as a tetramer of the trisaccharide repeating unit. By providing structural evidence for Fungitell cross-reactivity during nocardiosis, this work paves the way for developing specific diagnostic tools that are currently lacking.
Source: Journal of Biological Chemistry
Institutions: Centre National de la Recherche Scientifique, Université de Lille, Unité de Glycobiologie Structurale et Fonctionnelle, Institute of Biological Chemistry, Academia Sinica, Academia Sinica, National Taiwan University, Centre Hospitalier Universitaire de Lille, Inserm, Institute for Translational Research in Inflammation, Institut Pasteur de Lille, Approches épidémiologiques et moléculaires intégratives visant à améliorer la compréhension des maladies chroniques liées au vieillissement, Gifu University
Language: English
Subfield: Microbiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,430
OpenAlex ID: W4415892452