INTRODUCTION: Staphylococcus aureus-induced bloodstream infections (BSIs) remain a prevalent clinical challenge and the underlying pathogenesis is still poorly understood. The aim of this study was to investigate the inflammatory responses and histopathological changes in BSIs in mice. METHODOLOGY: Male C57BL/6 mice were inoculated with S. aureus intravenously to induce BSIs. The survival rate, weight loss, and murine sepsis scores (MSS) were monitored in BSI and phosphate-buffered saline (PBS) control mice. Blood samples and tissue homogenates were plated on agar plates to determine the bacterial burden. Inflammatory proteins and cytokines were determined by enzyme-linked immunosorbent assay (ELISA) kits. Histopathologic changes were assessed by pathological inflammation score (PIS) and macroscopic and microscopic examinations. RESULTS: BSI mice induced by 4.5 × 108 CFU/mL S. aureus showed ~70% survival rate, higher sepsis scores, significantly decreased body weight, elevated levels of white blood cell (WBC) counts, C-reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Prominent correlations were found between elevated CRP and PCT levels as well as among IL-1β, IL-6, and TNF-α. Pathological changes and higher PIS were also observed in BSI mice. CONCLUSIONS: Our results demonstrate that inflammatory proteins (PCT and CRP) and cytokines (IL-6, IL-1β and TNF-α) play an important role in the inflammatory responses and histopathological changes in S. aureus-induced BSIs.
INTRODUCTION:Staphylococcus aureus-induced bloodstream infections (BSIs) remain a prevalent clinical challenge and the underlying pathogenesis is still poorly understood. The aim of this study was to investigate the inflammatory responses and histopathological changes in BSIs in mice. METHODOLOGY: Male C57BL/6 mice were inoculated with S. aureus intravenously to induce BSIs. The survival rate, weight loss, and murinesepsis scores (MSS) were monitored in BSI and phosphate-buffered saline (PBS) control mice. Blood samples and tissue homogenates were plated on agar plates to determine the bacterial burden. Inflammatory proteins and cytokines were determined by enzyme-linked immunosorbent assay (ELISA) kits. Histopathologic changes were assessed by pathological inflammation score (PIS) and macroscopic and microscopic examinations. RESULTS: BSI mice induced by 4.5 × 108 CFU/mL S. aureus showed ~70% survival rate, higher sepsis scores, significantly decreased body weight, elevated levels of white blood cell (WBC) counts, C-reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Prominent correlations were found between elevated CRP and PCT levels as well as among IL-1β, IL-6, and TNF-α. Pathological changes and higher PIS were also observed in BSI mice. CONCLUSIONS: Our results demonstrate that inflammatory proteins (PCT and CRP) and cytokines (IL-6, IL-1β and TNF-α) play an important role in the inflammatory responses and histopathological changes in S. aureus-induced BSIs.
Authors: Amin Polzin; Lisa Dannenberg; René M'Pembele; Philipp Mourikis; David Naguib; Saif Zako; Carolin Helten; Tobias Petzold; Bodo Levkau; Thomas Hohlfeld; Mareike Barth; Tobias Zeus; Stephan Sixt; Ragnar Huhn; Payam Akhyari; Artur Lichtenberg; Malte Kelm; Till Hoffmann Journal: Sci Rep Date: 2022-07-28 Impact factor: 4.996