Viridans streptococcal isolates from patients with septic shock induce tumor necrosis factor-alpha production by...

Viridans streptococci are an important cause of bacteremia and septic shock in neutropenic patients, especially patients receiving chemotherapeutic agents that induce severe mucositis. The mechanisms by which viridans streptococci cause septic shock are unclear. We hypothesized that septic shock due to viridans streptococci is attributable to host cytokine production. Three clinical isolates of viridans streptococci were evaluated for their ability to induce production of tumor necrosis factor-alpha (TNF-alpha) by RAW 264.7 murine macrophages. These three strains of viridans streptococci induced TNF-alpha in a dose-dependent fashion, and the kinetics of TNF-alpha induction were similar to those observed with a clinical isolate of Escherichia coli.