scholarly journals Salmonella enterica Serovars Typhi and Paratyphi A are avirulent in newborn and infant mice even when expressing virulence plasmid genes of Salmonella Typhimurium

2010 ◽  
Vol 4 (11) ◽  
pp. 723-731 ◽  
Author(s):  
Javier Santander ◽  
Roy Curtiss III
Keyword(s):  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Systemic Infection ◽  
Virulence Plasmid ◽  
Susceptible Animal ◽  
Human Host ◽  
Adult Mice ◽  
Serovar Typhimurium ◽  
Plasmid Genes

Background: Salmonella enterica serovars Typhi and Paratyphi A are human host-restricted pathogens. Therefore, there is no small susceptible animal host that can be used to assess the virulence and safety of vaccine strains derived from these Salmonella serovars.  However, infant mice have been used to evaluate virulence and colonization by another human host-restricted pathogen, Vibrio cholerae.  Methodology: The possibility that infant mice host could be adapted for Salmonella led us to investigate the susceptibility of newborn and infant mice to oral infection with S. Typhi and S. Paratyphi A. Salmonella enterica serovar Typhimurium causes enteric fever in adult mice and this system has been used as a model for human typhoid. The pSTV virulence plasmid, not present in S. Typhi and S. Paratyphi A, plays an essential role in S. Typhimurium colonization and systemic infection of mice. We also conjugated pSTV into S. Typhi and S. Paratyphi A serovars and evaluated these transconjugants in newborn and infant mice.  Results: We determined that the spv virulence genes from the S. Typhimurium virulence plasmid are expressed in S. Typhi and S. Paratyphi A in a RpoS dependent fashion. Also, we determined that S. Typhi and S. Paratyphi A with and without pSTV transiently colonize newborn and infant mice tissues. Conclusion: Newborn and infant mice infected with S. Typhi and S. Paratyphi A do not succumb to the infection and that carriage of the S. Typhimurium virulence plasmid, pSTV, did not influence these results.

scholarly journals Virulence Plasmid-Borne spvB and spvC Genes Can Replace the 90-Kilobase Plasmid in Conferring Virulence to Salmonella enterica Serovar Typhimurium in Subcutaneously Inoculated Mice

2001 ◽  
Vol 183 (15) ◽  
pp. 4652-4658 ◽  
Author(s):  
Hidenori Matsui ◽  
Christopher M. Bacot ◽  
Wendy A. Garlington ◽  
Thomas J. Doyle ◽  
Steve Roberts ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Systemic Infection ◽  
Reticuloendothelial System ◽  
Host Cells ◽  
Virulence Plasmid ◽  
Replication Rate ◽  
Oral Inoculation ◽  
Low Copy Number ◽  
Serovar Typhimurium

ABSTRACT In a mouse model of systemic infection, the spv genes carried on the Salmonella enterica serovar Typhimurium virulence plasmid increase the replication rate of salmonellae in host cells of the reticuloendothelial system, most likely within macrophages. A nonpolar deletion in the spvB gene greatly decreased virulence but could not be complemented by spvBalone. However, a low-copy-number plasmid expressing spvBCfrom a constitutive lacUV5 promoter did complement thespvB deletion. By examining a series of spvmutations and cloned spv sequences, we deduced thatspvB and spvC could be sufficient to confer plasmid-mediated virulence to S. enterica serovar Typhimurium. The spvBC-bearing plasmid was capable of replacing all of the spv genes, as well as the entire virulence plasmid, of serovar Typhimurium for causing systemic infection in BALB/c mice after subcutaneous, but not oral, inoculation. A point mutation in the spvBC plasmid preventing translation but not transcription of spvC eliminated the ability of the plasmid to confer virulence. Therefore, it appears that both spvB and spvC encode the principal effector factors for Spv- and plasmid-mediated virulence of serovar Typhimurium.

scholarly journals Identification of GtgE, a Novel Virulence Factor Encoded on the Gifsy-2 Bacteriophage of Salmonella enterica Serovar Typhimurium

2002 ◽  
Vol 184 (19) ◽  
pp. 5234-5239 ◽  
Author(s):  
Theresa D. Ho ◽  
Nara Figueroa-Bossi ◽  
Minhua Wang ◽  
Sergio Uzzau ◽  
Lionello Bossi ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Systemic Infection ◽  
Open Reading Frames ◽  
Effector Protein ◽  
Protein Sequence Analysis ◽  
Serovar Typhimurium ◽  
Reading Frames

ABSTRACT The Gifsy-2 temperate bacteriophage of Salmonella enterica serovar Typhimurium contributes significantly to the pathogenicity of strains that carry it as a prophage. Previous studies have shown that Gifsy-2 encodes SodCI, a periplasmic Cu/Zn superoxide dismutase, and at least one additional virulence factor. Gifsy-2 encodes a Salmonella pathogenicity island 2 type III secreted effector protein. Sequence analysis of the Gifsy-2 genome also identifies several open reading frames with homology to those of known virulence genes. However, we found that null mutations in these genes did not individually have a significant effect on the ability of S. enterica serovar Typhimurium to establish a systemic infection in mice. Using deletion analysis, we have identified a gene, gtgE, which is necessary for the full virulence of S. enterica serovar Typhimurium Gifsy-2 lysogens. Together, GtgE and SodCI account for the contribution of Gifsy-2 to S. enterica serovar Typhimurium virulence in the murine model.

Detection of Virulence Plasmid–Encoded Genes in Salmonella Typhimurium and Salmonella Kentucky Isolates Recovered from Commercially Processed Chicken Carcasses

2019 ◽  
Vol 82 (8) ◽  
pp. 1364-1368 ◽  
Author(s):  
RIZWANA TASMIN ◽  
PAUL A. GULIG ◽  
SALINA PARVEEN
Keyword(s):  
United States ◽  
Salmonella Typhimurium ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
The United States ◽  
Clinical Isolates ◽  
Virulence Plasmid ◽  
Chicken Carcass ◽  
Serovar Typhimurium ◽  
Salmonella Virulence

ABSTRACT Salmonella enterica serovar Typhimurium is one of the leading causes of nontyphoidal gastroenteritis of humans in the United States. Commercially processed poultry carcasses are frequently contaminated with Salmonella serovar Kentucky in the United States. The aim of the study was to detect the Salmonella virulence plasmid containing the spv genes from Salmonella isolates recovered from commercially processed chicken carcasses. A total of 144 Salmonella isolates (Salmonella Typhimurium, n = 72 and Salmonella Kentucky, n = 72) were used for isolation of plasmids and detection of corresponding virulence genes (spvA, spvB, and spvC). Only four (5.5%) Salmonella Typhimurium isolates tested positive for all three virulence genes and hence were classified as possessing the virulence plasmid. All isolates of Salmonella Kentucky were negative for the virulence plasmid and genes. These results indicate that the virulence plasmid, which is very common among clinical isolates of Typhimurium and other Salmonella serovars (e.g., Enteritidis, Dublin, Choleraesuis, Gallinarum, Pullorum, and Abortusovis), may not be present in a significant portion of commercially processed chicken carcass isolates.

scholarly journals Cystathionine β-Lyase Is Important for Virulence of Salmonella enterica Serovar Typhimurium

2004 ◽  
Vol 72 (6) ◽  
pp. 3310-3314 ◽  
Author(s):  
Linda J. Ejim ◽  
Vanessa M. D'Costa ◽  
Nadine H. Elowe ◽  
J. Concepción Loredo-Osti ◽  
Danielle Malo ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Biosynthetic Pathway ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Systemic Infection ◽  
Bacterial Virulence ◽  
Methionine Biosynthesis ◽  
Insertional Inactivation ◽  
Serovar Typhimurium

ABSTRACT The biosynthesis of methionine in bacteria requires the mobilization of sulfur from Cys by the formation and degradation of cystathionine. Cystathionine β-lyase, encoded by metC in bacteria and STR3 in Schizosaccharomyces pombe, catalyzes the breakdown of cystathionine to homocysteine, the penultimate step in methionine biosynthesis. This enzyme has been suggested to be the target for pyridinamine antimicrobial agents. We have demonstrated, by using purified enzymes from bacteria and yeast, that cystathionine β-lyase is not the likely target of these agents. Nonetheless, an insertional inactivation of metC in Salmonella enterica serovar Typhimurium resulted in the attenuation of virulence in a mouse model of systemic infection. This result confirms a previous chemical validation of the Met biosynthetic pathway as a target for the development of antibacterial agents and demonstrates that cystathionine β-lyase is important for bacterial virulence.

scholarly journals Complete Genome Sequence of Salmonella enterica Serovar Typhimurium Strain SO3 (Sequence Type 302) Isolated from a Baby with Meningitis in Mexico

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Pablo Vinuesa ◽  
José L. Puente ◽  
Edmundo Calva ◽  
Mussaret B. Zaidi ◽  
Claudia Silva
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Salmonella Enterica ◽  
Complete Genome ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Sequence Type ◽  
Genomic Islands ◽  
Virulence Plasmid ◽  
Typhimurium Strain ◽  
Serovar Typhimurium

The complete genome of Salmonella enterica serovar Typhimurium strain SO3 (sequence type 302), isolated from a fatal meningitis infection in Mexico, was determined using PacBio technology. The chromosome hosts six complete prophages and is predicted to harbor 51 genomic islands, including 13 pathogenicity islands (SPIs). It carries the Salmonella virulence plasmid (pSTV).

scholarly journals Genome Sequences of 13 Isolates of Salmonella enterica Serovar Typhimurium var. Copenhagen Obtained from Wild Pigeons in Canada

2018 ◽  
Vol 6 (20) ◽  
Author(s):  
Bridget Xie ◽  
Andrée Ann Dupras ◽  
Marc-Olivier Duceppe ◽  
Nooshin Fattahi-Ghazi ◽  
Lawrence Goodridge ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Virulence Plasmid ◽  
Avian Host ◽  
Whole Genome ◽  
Genome Sequences ◽  
Content Type ◽  
Phage Types ◽  
Serovar Typhimurium

ABSTRACT Pigeon-adapted strains of Salmonella enterica serovar Typhimurium var. Copenhagen phage types 2 and 99 obtained from the provinces of Alberta, British Columbia, and Ontario, Canada, were analyzed using whole-genome sequencing. All isolates contained the Salmonella virulence plasmid despite the low pathogenicity of this lineage in their avian host.

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