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Updated: Jun 2, 2025
Oral Transmission of Listeria monocytogenes in Mice via Ingestion of Contaminated Food
Published on: May 6, 2013
Virulence expression difference to intestinal cells of different pathogenic Listeria monocytogenes contaminating
Cong Zhou1, Yafang Zou2, Haorui Huang2
1China National Center for Food Safety Risk Assessment Key Laboratory of Food Safety Risk Assessment, Beijing, PR China; State Key Laboratory of Meat Quality Control and Cultured Meat Development, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, PR China.
Abstract:
This study investigated the difference in survival among Listeria monocytogenes (LM) 10403S (highly pathogenic strain) and M7 (low pathogenic strain) in sausage under a simulated digestive environment, and established intestinal organoids and macrophages co-culture model to further explore the virulence expression difference to intestinal cells between LM 10403S and M7 after in vitro gastrointestinal digestion. Results showed that, compared with LM M7, LM 10403S exhibited a high survival rate during in vitro digestion, which may be due to the increased expression of stress response-related genes. In addition, the expression of virulence genes in LM 10403S was significantly higher than in LM M7 under the gastrointestinal environment. Furthermore, in the intestinal organoids and macrophages co-culture model infected by LM 10403S and M7 after in vitro gastrointestinal digestion, results showed that, compared with the LM M7 group, the LM 10403S group had significantly lower budding rate and significantly higher mortality of organoids. Also, the significantly increased LDH release and inflammatory factors (TNF-α and IL-1β) in the LM 10403S group were observed, and the main virulence genes (iap, inlA, inlB, actA, hly, plcA, and plcB) of 10403S were significantly highly expressed than LM M7 during the cell infection. These results reflected that the reason for the different pathogenicity between LM 10403S and M7 may be due to the high tolerance and the expression of virulence genes than LM M7 during gastrointestinal digestion and cell infection, which would be expected to provide a better understanding of the infection mechanisms among different pathogenic strains of L. monocytogenes in food.
Insights
Highly pathogenic Listeria monocytogenes (LM) 10403S survives better and expresses more virulence genes than low-pathogenic LM M7 during simulated digestion and intestinal cell infection. This explains differences in LM pathogenicity.
Area of Science:
- Food microbiology
- Pathogen survival
- Infectious disease mechanisms
Background:
- Listeria monocytogenes (LM) is a foodborne pathogen with varying pathogenicity.
- Understanding strain-specific virulence is crucial for food safety.
Purpose of the Study:
- To compare the survival and virulence expression of highly pathogenic LM 10403S and low-pathogenic LM M7.
- To investigate LM strain differences in a simulated digestive environment and an intestinal organoid model.
Main Methods:
- In vitro digestion of LM strains in sausage.
- Co-culture model using intestinal organoids and macrophages.
- Analysis of stress response and virulence gene expression.
- Assessment of organoid viability and inflammatory responses.
Main Results:
- LM 10403S showed higher survival and stress gene expression during simulated digestion compared to LM M7.
- LM 10403S exhibited significantly higher virulence gene expression under gastrointestinal conditions.
- In co-culture models, LM 10403S caused greater organoid mortality, increased LDH release, and elevated inflammatory factors (TNF-α, IL-1β).
- Key LM virulence genes were highly expressed in LM 10403S during cell infection.
Conclusions:
- Higher tolerance and virulence gene expression during digestion and infection contribute to the greater pathogenicity of LM 10403S.
- These findings enhance understanding of infection mechanisms among different Listeria monocytogenes strains in food.
