AUTHOR=Chauvelot Pierre , Ferry Tristan , Tafani Virginie , Diot Alan , Tasse Jason , Conrad Anne , Chidiac Christian , Braun Evelyne , Lustig Sébastien , Laurent Frédéric , Valour Florent
TITLE=Bone and Joint Infection Involving Corynebacterium spp.: From Clinical Features to Pathophysiological Pathways
JOURNAL=Frontiers in Medicine
VOLUME=7
YEAR=2021
URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2020.539501
DOI=10.3389/fmed.2020.539501
ISSN=2296-858X
ABSTRACT=Introduction: Corynebacteria represent often-neglected etiological agents of post-traumatic and/or post-operative bone and joint infection (BJI). We describe here clinical characteristics and bacteriological determinants of this condition.
Methods: A retrospective cohort study described characteristics, outcome and determinants of treatment failure of all patients with proven Corynebacterium spp. BJI (i.e., ≥2 culture-positive gold-standard samples). Available strains were further characterized regarding their antibiotic susceptibilies, abilities to form early (BioFilm Ring Test®) and mature (crystal violet staining method) biofilms and to invade osteoblasts (gentamicin protection assay).
Results: The 51 included BJI were mostly chronic (88.2%), orthopedic device-related (74.5%) and polymicrobial (78.4%). After a follow-up of 60.7 weeks (IQR, 30.1–115.1), 20 (39.2%) treatment failures were observed, including 4 Corynebacterium-documented relapses, mostly associated with non-optimal surgical management (OR 7.291; p = 0.039). Internalization rate within MG63 human osteoblasts was higher for strains isolated from delayed (>3 months) BJI (p < 0.001). Infection of murine osteoblasts deleted for the β1-integrin resulted in a drastic reduction in the internalization rate. No difference was observed regarding biofilm formation.
Conclusions: Surgical management plays a crucial role in outcome of BJI involving corynebacteria, as often chronic and device-associated infections. Sanctuarisation within osteoblasts, implicating the β1 cellular integrin, may represent a pivotal virulence factor associated with BJI chronicity.