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Updated: Apr 24, 2026
Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
Published on: January 17, 2025
In vitro Staphylococcus aureus-induced oxidative stress in mice murine peritoneal macrophages: a duration-dependent
Subhankari Prasad Chakraborty1, Somenath Roy1
1Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore-721 102, West Bengal, India.
Objective:
To evaluate the free radical generation and status of the antioxidant enzymes in murine peritoneal macrophage during in vitro vancomycin sensitive Staphylococcus aureus (VSSA) treatment with different time interval.
Methods:
Peritoneal macrophages were treated with 5×10(6) CFU/mL VSSA cell suspension in vitro for different time interval (1, 2, 3, 6, 12, and 24 h) and superoxide anion generation, NADPH oxidase activity, myeloperoxidase activity, nitric oxide generation, antioxidant enzyme status and components of glutathione cycle were analyzed.
Results:
Superoxide anion generation, NADPH oxidase activity, myeloperoxidase activity and nitric oxide generation got peak at 3 h, indicating maximum free radical generation through activation of NADPH oxidase in murine peritoneal macrophages during VSSA infection. Reduced glutathione level, glutathione peroxidase, glutathione reductase, and glutathione-s-transferase activity were decreased significantly (P<0.05) with increasing time of VSSA infection. But the oxidized glutathione level was time dependently increased significantly (P<0.05) in murine peritoneal macrophages. All the changes in peritoneal macrophages after 3 h in vitro VSSA treatment had no significant difference.
Conclusions:
From this study, it may be summarized that in vitro VSSA infection not only generates excess free radical but also affects the antioxidant status and glutathione cycle in murine peritoneal macrophages.
Insights
Vancomycin-sensitive Staphylococcus aureus (VSSA) infection in murine macrophages generates excess free radicals and depletes antioxidants. This oxidative stress peaks at 3 hours, impacting the glutathione cycle and antioxidant enzyme status.
Area of Science:
- Immunology
- Microbiology
- Biochemistry
Background:
- Murine peritoneal macrophages are crucial immune cells involved in combating bacterial infections.
- Staphylococcus aureus (S. aureus) infections can lead to significant oxidative stress within host cells.
- Understanding the interplay between bacterial infection and macrophage antioxidant defense is vital for therapeutic strategies.
Purpose of the Study:
- To investigate the impact of vancomycin-sensitive Staphylococcus aureus (VSSA) on free radical generation in murine peritoneal macrophages.
- To assess the status of antioxidant enzymes and the glutathione cycle during VSSA infection over various time intervals.
- To determine the kinetics of oxidative stress markers in macrophages following VSSA exposure.
Main Methods:
- Murine peritoneal macrophages were exposed to VSSA (5×10^6 CFU/mL) in vitro for 1, 2, 3, 6, 12, and 24 hours.
- Analysis included superoxide anion and nitric oxide generation, NADPH oxidase and myeloperoxidase activity.
- Antioxidant enzyme status and glutathione cycle components (reduced and oxidized glutathione) were quantified.
Main Results:
- Peak free radical generation, evidenced by increased superoxide anion, nitric oxide, NADPH oxidase, and myeloperoxidase activity, occurred at 3 hours post-VSSA infection.
- Significant time-dependent decreases in reduced glutathione levels and activities of glutathione peroxidase, reductase, and transferase were observed.
- Conversely, oxidized glutathione levels increased significantly over time, indicating heightened oxidative stress.
- Changes observed up to 3 hours showed no significant difference after this time point.
Conclusions:
- In vitro VSSA infection induces substantial free radical generation in murine peritoneal macrophages.
- VSSA infection significantly disrupts the antioxidant defense system, including the glutathione cycle.
- These findings highlight the complex oxidative response of macrophages to bacterial challenge.
