Establishment of a chinchilla model of Achromobacter xylosoxidans-induced otitis media. Microbiol Spectr 2026 Aug 04;14(8):e0098526
Date
07/06/2026Pubmed ID
42405782Pubmed Central ID
PMC13436351DOI
10.1128/spectrum.00985-26Scopus ID
2-s2.0-105046762645 (requires institutional sign-in at Scopus site)Abstract
UNLABELLED: Achromobacter xylosoxidans (Ax) is an emerging opportunistic pathogen associated with chronic respiratory infections, particularly in individuals with cystic fibrosis; however, its role in otitis media (OM) and the mechanisms that underlie middle ear infection remain poorly defined. Despite its initial isolation from middle ear effusions decades ago, no experimental models of Ax-induced OM have been established. Here, we report the development of a reproducible chinchilla model of Ax-induced OM, which, to our knowledge, represents the first experimental model of Ax-induced middle ear infection. Following transbullar inoculation, two well-characterized clinical isolates established middle ear infection and induced measurable changes in tympanometry and otoscopic pathology. Notably, strain-specific differences in disease severity and persistence were observed, with one isolate inducing more pronounced inflammation, reduced tympanic membrane compliance, and prolonged bacterial survival within the middle ear mucosa. At the study endpoint, viable bacteria were recovered from a subset of infected ears despite resolution of overt clinical signs, which indicated a capacity for persistent mucosal infection. These findings demonstrate that Ax can establish and maintain infection within the middle ear and that clinical isolates exhibit distinct pathogenic phenotypes in this model. Together, this work establishes a reproducible and clinically relevant in vivo model for the study of Ax-induced OM and provides a foundation for future investigations into host-pathogen interactions, persistence mechanisms, and therapeutic interventions.
IMPORTANCE: Achromobacter xylosoxidans is an emerging opportunistic pathogen increasingly associated with chronic mucosal infection, yet its role in otitis media remains poorly defined. Mechanistic studies of middle ear infection have been limited by the absence of an experimental model. We establish the first reproducible animal model of A. xylosoxidans-induced otitis media and demonstrate that clinical isolates differ in their capacity to drive disease severity within the middle ear. By enabling controlled investigation of infection dynamics in vivo, this model provides a framework to define determinants of pathogenesis and directly compare strain-specific phenotypes across mucosal environments. These findings establish a foundation for future studies of A. xylosoxidans infection and therapeutic intervention.
Author List
Khampang P, Brockman KLAuthor
Kenneth Brockman PhD Assistant Professor in the Microbiology and Immunology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Achromobacter denitrificansAnimals
Chinchilla
Disease Models, Animal
Ear, Middle
Gram-Negative Bacterial Infections
Humans
Otitis Media
