Virulence Factors and Pathogenic Mechanisms of Salmonella enterica Serovar Typhi: A Narrative Review Virulence Factors of Salmonella enterica Serovar Typhi: A Narrative Review
Article Sidebar
Main Article Content
Abstract
Abstract
Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi), remains a major public health concern, particularly in low- and middle-income countries. The pathogenic success of S. Typhi is driven by a sophisticated array of virulence factors that enable host colonization, immune evasion, systemic dissemination, and long-term persistence. Key determinants include Type III Secretion Systems (T3SS), the Vi capsular polysaccharide, Salmonellapathogenicity islands (SPIs), lipopolysaccharide (LPS), and multiple secreted effector proteins. This review aims to summarize the major virulence factors of S. Typhi and elucidate the molecular mechanisms underlying host–pathogen interactions, immune modulation, systemic infection, and chronic persistence. It further seeks to highlight recent advances in molecular pathogenesis and genomics that inform vaccine development and novel therapeutic strategies. A comprehensive review of current literature was conducted, focusing on molecular, genetic, and genomic studies of S. Typhi virulence. Peer-reviewed articles addressing T3SS function, SPIs, capsular and surface antigens, intracellular survival strategies, and host immune responses were analyzed to integrate current knowledge on S. Typhi pathogenicity. In conclusions: the coordinated action of S. Typhi virulence factors enable efficient invasion, immune evasion, and systemic spread, while specific determinants support survival within host macrophages and persistence in the gallbladder, leading to chronic carriage. Advances in genomics and molecular pathogenesis have deepened understanding of host–pathogen interactions and revealed promising molecular targets for vaccine design and innovative therapeutics. A thorough understanding of S. Typhi pathogenic mechanisms is essential for improving typhoid fever prevention, treatment, and control strategies, particularly in endemic regions where the disease burden remains high.
Article Details
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
The Journal of Medical and Oral Biosciences uses a Creative Commons Attribution (CC Attribution-ShareAlike 4.0) and its license of (CC BY-SA 4.0). This license allows the authors to hold ownership of the copyright of their articles.
Attribution-Share Alike 4.0 International License (CC BY-SA 4.0). 
Under the CC BY-SA 4.0 the authors are free to:
Share — copy and redistribute the material in any medium or format for any purpose, even commercially.
Adapt — remix, transform, and build upon the material for any purpose, even commercially.
The licensor cannot revoke these freedoms as long as you follow the license terms.
Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
No use, distribution or reproduction is permitted which does not comply with these terms.
https://creativecommons.org/licenses/by-sa/4.0/