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Updated: Aug 13, 2025
06:30
A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis
Published on: January 27, 2021
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A Small RNA, SaaS, Promotes Salmonella Pathogenicity by Regulating Invasion, Intracellular Growth, and Virulence
Lin-Lin Cai1, Yun-Ting Xie1, Hai-Jing Hu1
1Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, People's Republic of China.
Microbiology Spectrum
|January 23, 2023
Summary
Salmonella adhesive-associated sRNA (SaaS) is crucial for Salmonella Enteritidis virulence. This small RNA regulates pathogen invasion, survival, and inflammation, impacting host health and disease severity.
Area of Science:
- Microbiology
- Molecular Biology
- Pathogenesis
Background:
- Salmonella enterica serovar Enteritidis is a significant foodborne pathogen.
- The virulence regulation network of S. Enteritidis and the role of small RNAs (sRNAs) are not fully understood.
Purpose of the Study:
- To investigate the role of the sRNA SaaS in the virulence of S. Enteritidis.
- To elucidate the molecular mechanisms by which SaaS contributes to bacterial pathogenesis.
Main Methods:
- Construction and analysis of mutant (ΔsaaS) and complemented (ΔsaaS/pSaas) S. Enteritidis strains.
- In vitro assays using Caco-2 and RAW 264.7 cell lines to assess invasion, epithelial damage, and macrophage interaction.
- In vivo studies using a BALB/c mouse model to evaluate mortality, pathophysiology, bacterial dissemination, and systemic inflammation.
Main Results:
- SaaS is activated in a simulated intestinal environment (SIE) and directly binds to ssaV mRNA.
- SaaS promotes S. Enteritidis invasion and damage to epithelial cells.
- SaaS suppresses macrophage overgrowth and destruction.
- Deletion of SaaS significantly reduces mortality, bacterial dissemination, and systemic inflammation in mice.
Conclusions:
- SaaS is essential for S. Enteritidis virulence, playing a critical role in bacterial pathogenesis.
- SaaS acts as an SIE-responsive sRNA that regulates virulence-targeted genes.
- SaaS differentially mediates invasion and intracellular growth, contributing to host cell survival and infection.
- SaaS enhances bacterial lethality, colonization, and inflammatory responses, highlighting its importance in Salmonella virulence.
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