Salmonella entericaserovars Typhimurium and Typhi as model organisms

Abstract

The lifestyle of intracellular pathogens has always questioned the skill of a microbiologist in the context of finding the permanent cure to the diseases caused by them. The best tool utilized by these pathogens is their ability to reside inside the host cell, which enables them to easily bypass the humoral immunity of the host, such as the complement system. They further escape from the intracellular immunity, such as lysosome and inflammasome, mostly by forming a protective vacuole-bound niche derived from the host itself. Some of the most dreadful diseases are caused by these vacuolar pathogens, for example, tuberculosis by Mycobacterium or typhoid fever by Salmonella. To deal with such successful pathogens therapeutically, the knowledge of a host-pathogen interaction system becomes primarily essential, which further depends on the use of a model system. A well characterized pathogen, namely Salmonella, suits the role of a model for this purpose, which can infect a wide array of hosts causing a variety of diseases. This review focuses on various such aspects of research on Salmonella which are useful for studying the pathogenesis of other intracellular pathogens.

Bacterial peptide transporters: Messengers of nutrition to virulence

“…Commencement of nutrient starvation in stationary phase of growth is reported to induce carbon starvation (Cst) family of PTR peptide transporters, i.e., CstA and YjiY, via cAMP, in E. coli and Salmonella. 13,[71][72][73] In E. coli. the exponential phase specific global regulator protein CsrA negatively regulates the translation of CstA by binding to cstA mRNA.…”

Impact ofSalmonella entericaType III Secretion System Effectors on the Eukaryotic Host Cell

“…The typical intracellular niche of Salmonella is a modified phagolysosome known as Salmonella-containing vacuole (SCV), but the mode of entry and the strategy to survive inside the target cells varies according to the type of cell and depends on the temporal expression of particular genes by Salmonella. Target cells include M cells, gut epithelial cells, macrophages, neutrophils, monocytes, dendritic cells, granulocytes, B cells, and T cells [4].…”

Salmonella enterica Serovar Typhi and Paratyphi Responsible of Typhoid and Paratyphoid Fevers Transmitted by Environment and Food

“…The bacteria continue their intracellular multiplication inside vacuoles. Intestinal invasion by Salmonella induces an inflammatory response causing ulcers responsible for the secretion of water and electrolytes (Garai et al, 2012). Salmonella has an arsenal of virulence factors that play a role at different stages of the infectious process.…”

“…These roles in virulence studied in vivo on cell cultures, and in vitro on animal experimental models is controversial little known. The major contribution in the virulence of Salmonella is linked to the various tools and mechanisms of virulence codified by islands of pathogenicities constituted mainly by: type III secretion systems (TTSS), effectors secreted by TTSS, fimbriae, of iron capture (Garai et al, 2012).…”