In-vitro Study and In-vivo Application of Rileva IVD System for the Isolation and Cultivation of Bacterial Strains from Biofilm

Introduction: Diagnosis of infection is often complicated by the inability to isolate the pathogens, due to their ability to aggregate into complex structures known as biofilms. This article collects in-vitro and in-vivo evidence of the efficacy of an in-vitro diagnostic (IVD) (RILEVA, Joint Srl, Venice) for the harvesting of explanted prostheses and peri-implant tissues, specifically designed for biofilm breakdown. Methods: To prove the in-vitro efficacy of the RILEVA IVD, the biofilm of the bacteria E. coli, P.aeruginosa [Gram+] and S.epidermidis [Gram-] was grown for 14 days both on polyethylene (PE) and titanium (Ti) discs. The discs were then placed in the polyvinyl chloride (PVC) bag of RILEVA with a solution of Dithiothreitol (DTT). The solution was processed and centrifuged; the pellet was cultured for up to 10 days on Petri dishes. Data from the clinical use of IVD in 28 cases were analyzed to confirm the in-vitro evidence. Results: Colonies of all three tested strains of bacteria grew abundantly on the Petri dishes with high colony density in all six replicates, indicative of RILEVA’s effectiveness in disrupting the biofilm and identifying the pathogen. Results from the clinical use of the IVD demonstrated the efficacy, confirming in 96.4% of the cases the pre/intraoperative diagnosis. Conclusion: The RILEVA system, an IVD device that uses DTT to dissolve the biofilm matrix and release sessile bacteria present in the prosthesis, effectively identified the causative agent of prosthetic infection, both in-vitro and when used in a clinical setting.