Typhoidal Salmonella: Distinctive virulence factors and pathogenesis

@article{Johnson2018TyphoidalSD,
  title={Typhoidal Salmonella: Distinctive virulence factors and pathogenesis},
  author={Rebecca Johnson and Elli Mylona and Gad Frankel},
  journal={Cellular Microbiology},
  year={2018},
  volume={20}
}
Although nontyphoidal Salmonella (NTS; including Salmonella Typhimurium) mainly cause gastroenteritis, typhoidal serovars (Salmonella Typhi and Salmonella Paratyphi A) cause typhoid fever, the treatment of which is threatened by increasing drug resistance. Our understanding of S. Typhi infection in human remains poorly understood, likely due to the host restriction of typhoidal strains and the subsequent popularity of the S. Typhimurium mouse typhoid model. However, translating findings with S… 
Salmonella Typhoid Toxin PltB Subunit and Its Non-typhoidal Salmonella Ortholog Confer Differential Host Adaptation and Virulence.
TLDR
It is found that typhoid toxin and its NTS ortholog induce different clinical presentations, offering insights into the evolution of host adaptations in Salmonella AB toxins, their cell and tissue tropisms, and the design for improved typhoid vaccines and therapeutics.
Salmonella Virulence and Immune Escape
TLDR
The functions of Salmonella virulence genes are characterized and the mechanisms of immune escape in light of evidence from the emerging mainstream literature are focused on.
Pathoadaptive Alteration of Salmonella Biofilm Formation in Response to the Gallbladder Environment
Chronic carriers are the main reservoirs for the spread of typhoid fever in regions of endemicity. Salmonella Typhi forms biofilms on gallstones in order to persist. A strain with enhanced
The YrbE phospholipid transporter of Salmonella enterica serovar Typhi regulates the expression of flagellin and influences motility, adhesion and induction of epithelial inflammatory responses
TLDR
The results point to an important and serovar-specific role played by yrbE in the early stages of intestinal infection by S. Typhi, which has no significant effect on flagellin expression, motility or adhesion to HeLa cells.
Pathoadaptation of the passerine-associated Salmonella enterica serovar Typhimurium lineage to the avian host
TLDR
The findings demonstrate a unique phenotypic profile and genetic makeup of an overlooked S. Typhimurium sparrow-associated lineage and present distinct genetic signatures that are likely to contribute to its pathoadaptation to passerine birds.
Evolution of Salmonella enterica serotype Typhimurium driven by anthropogenic selection and niche adaptation
TLDR
The population structure of diverse strains of S. Typhimurium revealed a major phylogroup of predominantly sequence type 19 (ST19) and a minor phylogroups of ST36, which were consistent with elevated anthropogenic selection of clade α lineages from adaptation to circulation in populations of domesticated livestock, and the predisposition ofClade β lineages to undergo adaptation to an invasive lifestyle by a process of convergent evolution with of host adapted Salmonella serotypes.
Evolution of Salmonella enterica serotype Typhimurium driven by anthropogenic selection and niche adaptation
TLDR
A robust fully parsimonious phylogenetic tree constructed from recombination purged variation in the whole genome sequence of 131 diverse strains of S. Typhimurium revealed population structure composed of two high order clades and multiple subclades on extended internal branches, that exhibited distinct signatures of host adaptation and anthropogenic selection.
SopA inactivation or reduced expression is selected in intracellular Salmonella and contributes to systemic Salmonella infection.
TLDR
It is demonstrated that sopA inactivation or intracellular repression is the target of positive selection during the systemic infection caused by S. enterica serovar Typhi and Paratyphi A.
Host restriction, pathogenesis and chronic carriage of typhoidal Salmonella
TLDR
In this review, mechanisms of host restriction, intestinal invasion, interactions with innate immunity and chronic carriage are outlined, and how this knowledge may progress future vaccines and antimicrobials are discussed.
Activation of apoptosis by Salmonella pathogenicity island-1 effectors through both intrinsic and extrinsic pathways in Salmonella-infected macrophages.
TLDR
Non-typhoid Salmonella induced apoptosis of macrophages and thereby reduced inflammatory cytokine production through the expression of SPI-1, which may explain whySalmonella usually manifests as occult bacteremia with less systemic inflammatory response syndrome in the bloodstream infection of children.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 198 REFERENCES
Comparison of Salmonella enterica Serovars Typhi and Typhimurium Reveals Typhoidal Serovar-Specific Responses to Bile
TLDR
Overall, it is found that S. Typhi exhibits a specific response to bile, especially with regard to virulence gene expression, which could impact pathogenesis and transmission.
Typhoidal Salmonella serovars: ecological opportunity and the evolution of a new pathovar
TLDR
The morbidity and mortality resulting from the severe systemic infection that enables typhoidal Salmonella serovars to reach the gall bladder is coupled to their capacity for infectious transmission, which is the principal driving force of natural selection directing the emergence of this pathovar.
Salmonella enterica serovar Typhi and the pathogenesis of typhoid fever.
TLDR
The latest scientific advances in typhoid research are reviewed and it is discussed how these novel approaches are changing the authors' understanding of the disease.
Feverlike Temperature is a Virulence Regulatory Cue Controlling the Motility and Host Cell Entry of Typhoidal Salmonella.
TLDR
Elevated physiological temperature is a novel cue controlling virulence phenotypes in typhoidal serovars, which is likely to play a role in the distinct clinical manifestations elicited by typhoidal and nontyphoidal salmonellae.
Virulence Gene Profiling and Pathogenicity Characterization of Non-Typhoidal Salmonella Accounted for Invasive Disease in Humans
TLDR
A common core of virulence genes might be required for invasive salmonellosis, but also an impressive degree of genetic and phenotypic heterogeneity is demonstrated, highlighting that bacteremia is a complex phenotype, which cannot be attributed merely to an enhanced invasion or intracellular growth of a particular strain.
Structure and function of the Salmonella Typhi chimaeric A2B5 typhoid toxin
TLDR
The atomic structure of typhoid toxin is presented, which shows an unprecedented A2B5 organization with two covalently linked A subunits non-covalently associated to a pentameric B subunit that provides insight into the toxin’s receptor-binding specificity and delivery mechanisms and reveals how the activities of two powerful toxins have been co-opted into a single, unique toxin.
A mouse model for the human pathogen Salmonella typhi.
TLDR
It is found that immunodeficient Rag2(-/-) γc (-/-) mice engrafted with human fetal liver hematopoietic stem and progenitor cells are able to support S. Typhi replication and persistent infection.
Intracellular survival of Salmonella enterica serovar Typhi in human macrophages is independent of Salmonella pathogenicity island (SPI)-2.
TLDR
Surprisingly, the data suggest that the SPI-2 T3SS of S. Typhi is not required for survival in human macrophages.
The Type III Secretion System Effector SptP of Salmonella enterica Serovar Typhi
TLDR
The results suggest that SptP is not translocated from typhoidal serovars, even though the loss of sptP results in virulence defects in S. Typhimurium, and that changes within the chaperone-binding domain of SPTP inS.
Mechanisms to Evade the Phagocyte Respiratory Burst Arose by Convergent Evolution in Typhoidal Salmonella Serovars
TLDR
It is concluded that the ability to avoid the phagocyte respiratory burst is a property distinguishing typhoidal from non-typhoidal Salmonella serovars that was acquired by S. Typhi and S. Paratyphi A independently through convergent evolution.
...
1
2
3
4
5
...