Infectious Causes of Cholesteatoma and Treatment of Infected Ossicles prior to Reimplantation by Hydrostatic High-Pressure Inactivation

Figure 1

Flow chart of the experimental setup for high hydrostatic pressure treatment on human ossicles. After surgical explanation of human ossicles the bones were cut into two equally sized pieces but in case of additionally antibiotic treatment the bones were cut into six equally sized pieces. Piece(s) A was/were HHP-treated at 350 MPa for 10 min, while Piece(s) B was/were kept in a sterile humid chamber. Optionally, the pieces were treated with either cefuroxime 11.1 mg/mL, gentamicin 44.4 mg/mL, and imipenem 3.7 mg/mL or vancomycin 11.1 mg/mL, clindamycin 0.75 mg/mL, and imipenem 3.7 mg/mL. After treatment, microbial colonization was assessed by electron microscopy and microbial culture. Prior microbial culture bacterial biofilms were mobilized by ultrasound treatment. Microbial species identification was performed using MALDI-TOF MS (Bruker Daltonics, Bremen, Germany), VITEC 2 identification (bioMérieux, Nürtingen, Germany), and 16S/18S rDNA sequencing. For in-depth reading, see [23, 44].