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Updated: Oct 28, 2025
Author Spotlight: Advancements in Understanding and Combatting Shigella Infections
Published on: February 9, 2024
Au Nanoclusters Ameliorate Shigella Infectious Colitis by Inducing Oxidative Stress
Xiaoxiao Wu1, Yongyan Chen1, Yangheng Zhang2
1Xuzhou Key Laboratory of Laboratory Diagnostics, School of Medical Technology, Xuzhou Medical University, Xuzhou, 221004, People's Republic of China.
Insights
Ultrasmall gold nanoclusters (Au NCs) show significant antibacterial effects against Shigella infections by disrupting bacterial metabolism and membranes. These findings suggest Au NCs are a promising, safe alternative to traditional antibiotics for treating Shigella.
Area of Science:
- Biomedical Science
- Nanotechnology
- Infectious Disease Research
Background:
- Shigella infection poses a global health challenge, particularly affecting young children.
- Antibiotic resistance necessitates the development of alternative, safe treatments.
- Ultrasmall gold nanoclusters (Au NCs) exhibit unique properties for interacting with bacteria.
Purpose of the Study:
- To investigate the potential of Au NCs as a non-antibiotic treatment for Shigella infections.
- To evaluate the bactericidal efficacy and safety of Au NCs against Shigella.
Main Methods:
- In vitro co-culture of Au NCs with Shigella strains to assess bactericidal activity.
- Scanning electron microscopy (SEM) to observe bacterial damage and Au NCs' mode of action.
- In vivo studies in mice to evaluate effects on body weight, clinical signs, and colon health.
- Analysis of fecal lipocalin-2 (LCN2) and Shigella load.
- Assessment of Shigella biofilm activity, reactive oxygen species (ROS) generation, and gene expression related to metabolism and cell membranes.
Main Results:
- Au NCs (100 μM) significantly inhibited Shigella growth by interfering with oxidative metabolism genes and increasing ROS levels.
- Au NCs disrupted the bacterial cell membrane, leading to bacterial death.
- In vivo studies demonstrated alleviation of intestinal damage in mice and reduced Shigella load.
- Reduced Shigella biofilm activity was observed.
Conclusions:
- Au NCs demonstrate effective antibacterial properties against Shigella.
- The observed good safety profile suggests Au NCs are a viable alternative to antibiotics for Shigella infections.
Background:
Shigella infection has always been a global burden, and it particularly threatens children between the ages of 1 and 5 years. Economically underdeveloped countries are dominated by Shigella flexneri infection. The most effective method to treat Shigella is antibiotics, but with the abuse of antibiotics and the prevalence of multidrug resistance, we urgently need a relatively safe non-antibiotic treatment to replace it. Ultrasmall Au nanoclusters (NCs) have special physical and chemical properties and can better interact with and be internalized by bacteria to disrupt the metabolic balance. The purpose of this study was to explore whether Au NCs may be a substitute for antibiotics to treat Shigella infections.
Methods:
Au NCs and Shigella Sf301, R2448, and RII-1 were cocultured in vitro to evaluate the bactericidal ability of Au NCs. The degree of damage and mode of action of Au NCs in Shigella were clearly observed in images of scanning electron microscopy (SEM). In vivo experiments were conducted to observe the changes in body weight, clinical disease activity index (DAI) and colon (including length and histopathological sections) of mice treated with Au NCs. The effect of Au NCs was analysed by measuring the content of lipocalin-2 (LCN2) and Shigella in faeces. Next, the changes in Shigella biofilm activity, the release of reactive oxygen species (ROS), the changes in metabolism-related and membrane-related genes, and the effect of Au NCs on the body weight of mice were determined to further analyse the mechanism of action and effect.
Results:
Au NCs (100 μM) interfered with oxidative metabolism genes, induced a substantial increase in ROS levels, interacted with the cell membrane to destroy it, significantly killed Shigella, and effectively alleviated the intestinal damage caused by Shigella in mice. The activity of the biofilm formed by Shigella was reduced.
Conclusion:
The effective antibacterial effect and good safety suggest that Au NCs represent a good potential alternative to antibiotics to treat Shigella infections.
