#557 Seraph® 100 affinity blood cartridge as a potential adjunctive blood purification strategy for S. aureus-induced septic shock

Abstract

Abstract Background and Aims S. aureus infections, particularly methicillin-resistant strains, can induce severe conditions, provoking an overwhelming immune response and contributing to systemic inflammation and organ failure. Effective antibiotic therapy and meticulous supportive care are crucial in the ICU to manage S. aureus-induced septic shock. In this context, blood purification strategies aim to target the microorganism and associated toxins, contributing to the systemic inflammatory cascade. The objective of this in-vitro study was to analyze the potential removal, through adsorption, by the Seraph100 Affinity Blood Cartridge (S100ABC) against S. aureus. Subsequently, the study assessed whether the adsorptive capabilities toward bacteria were maintained, and if so, whether the bacteria retained its bactericidal activity. Method The study employed an in vitro model of hemoadsorption to characterize the adsorption performed by the S100ABC on a circulating bacterial load inoculated in blood. A volume of 150 ml of blood served as a negative control (CTR-). The remaining 650 mL were enriched with a concentration of S. aureus bacteria equal to 1×106 and incubated for 4 h at 37°C. At 4 h, the blood was divided into 2 glass bowls and stirred at 37°C: 500 mL were circulated at a speed of 120 mL/min via a dedicated test platform (Galileo) with Seraph100, while another 150 mL was stirred and used as a positive control (CTR+). The experiment was performed twice. Samples were taken from circulating blood and the two controls for blood cultures and placement on CNA agar. Results This study demonstrated that the S100ABC reduces the circulating bacterial load (from 1x106 at T0 to 0.25x106 at T6 h), leading to the adsorption of bacteria onto the cartridge. Bacteria were found adhering to the beads contained in the cartridge. Conclusion Our preliminary data show that the S100ABC effectively reduces the circulating bacterial load. The S100ABC could be an adjunct sorbent for reducing S. aureus in human blood, supporting antibiotic therapy in patients with S. aureus-induced septic shock.