Unexpected Listeria monocytogenes detection with a dithiothreitol-based device during an aseptic hip revision [*G. Banche and A. Bistolfi contributed equally to this work; ** V. Allizond is the corresponding author]

Prosthetic joint infection diagnosis is often difficult since biofilm-embedded microorganisms attach well to the prosthetic surfaces and resist their detection by conventional methods. DL-dithiothreitol has been described as a valid method for biofilm detachment on orthopedic devices. We report the case of an occasional detection of Listeria monocytogenes in a non immuno-compromised patient with a preoperative diagnosis of aseptic loosening. The infection diagnosis due to such rare bacteria was made postoperatively, thanks to a DL-dithiothreitol-based device. This may be considered a feasible approach for the microbiological analysis of prosthetic joint infection, considering that a prompt diagnosis of such biofilmassociated infections could bring some advantages, such as an early and appropriate antibiotic therapy administration and a reduction of undiagnosed infections.