Corynebacterium spp have been considered as innocuous commensals of human skin, but are now accepted as important opportunistic pathogens responsible for various nosocomial infections, especially implicating foreign materials. In particular, they accounted for up to 10% of prosthetic joint infection (PJI), and are mostly identified in chronic forms of bone and joint infections (BJI). However, little is known about the pathophysiological pathway implicated in Corynebacterium BJI, species distribution and antimicrobial susceptibility, and the management of these difficult-to-treat clinical entities.

This study aims to report a retrospective cohort of patients with Corynebacterium spp BJI, aiming to : i) describe microbiological characteristics of the implicated clinical isolates, including species identification and antimicrobial susceptibility (and especially according to previous antimicrobial exposure); ii) assess pathophysiological mechanisms associated with BJI chronicity, including biofilm formation and bone cell invasion, to better understand mechanisms of Corynebacterium spp and to evaluate their ability to distinguished colonizing and infective isolates; iii) describe the medical (nature and duration of antimicrobial therapy) and surgical management of these patients; and iv) evaluate the patient outcome according to this management strategy, and highlight risk factor for treatment failure in order to improve patient's management.

Inclusion Criteria:

• Adult patients (i.e age ≥ 18-year-old) with microbiologically proven Corynebacterium bone and joint infection, with or without implant

Exclusion Criteria:

• diabetic foot osteomyelitis
• pressure ulcer-associated osteomyelitis

patients with microbiologically proven Corynebacterium bone and joint infection.