scholarly journals Impact of the Lipopolysaccharide Chemotype of Salmonella Enterica Serovar Typhimurium on Virulence in Gnotobiotic Piglets

Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 534 ◽  
Author(s):  
Alla Splichalova ◽  
Zdislava Splichalova ◽  
Daniela Karasova ◽  
Ivan Rychlik ◽  
Paolo Trevisi ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Chronic Infections ◽  
Mesenteric Lymph Nodes ◽  
Protein Levels ◽  
Tnf Α ◽  
Serovar Typhimurium ◽  
Gnotobiotic Piglet ◽  
Isogenic Mutants ◽  
Junction Proteins

Salmonella Typhimurium is an enteric pathogen that causes acute and chronic infections in humans and animals. One-week-old germ-free piglets were orally colonized/infected with the Salmonella Typhimurium LT2 strain or its isogenic rough ΔrfaL, ΔrfaG or ΔrfaC mutants with exactly defined lipopolysaccharide (LPS) defects. After 24 h, the piglets were euthanized and the colonization of the small intestine, translocations into the mesenteric lymph nodes, liver, spleen, lungs, and bacteremia, along with changes in the ileum histology, and transcription levels of the tight junction proteins claudin-1, claudin-2, and occludin were all assessed. Additionally, transcription levels of IL-8, TNF-α, and IL-10 in the terminal ileum, and their local and systemic protein levels were evaluated. Wild-type Salmonella Typhimurium showed the highest translocation, histopathological changes, upregulation of claudins and downregulation of occludin, transcription of the cytokines, intestinal IL-8 and TNF-α levels, and systemic TNF-α and IL-10 levels. Depending on the extent of the incompleteness of the LPS, the levels of the respective elements decreased, or no changes were observed at all in the piglets colonized/infected with Δrfa mutants. Intestinal IL-10 and systemic IL-8 levels were not detected in any piglet groups. This study provided foundational data on the gnotobiotic piglet response to colonization/infection with the exactly defined rough Salmonella Typhimurium LT2 isogenic mutants.

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 Role of Toll-Like Receptor 4 in Macrophage Activation and Tolerance during Salmonella enterica Serovar Typhimurium Infection

2003 ◽  
Vol 71 (9) ◽  
pp. 4873-4882 ◽  
Author(s):  
Qian Li ◽  
Bobby J. Cherayil
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Peritoneal Macrophages ◽  
Phagocytic Cells ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Serovar Typhimurium ◽  
Tlr4 Gene ◽  
Factor Alpha

ABSTRACT Toll-like receptors (TLRs) play an important role in the innate immune response, particularly in the initial interaction between the infecting microorganism and phagocytic cells, such as macrophages. We investigated the role of TLR4 during infection of primary murine peritoneal macrophages with Salmonella enterica serovar Typhimurium. We found that macrophages from the C3H/HeJ mouse strain, which carries a functionally inactive Tlr4 gene, exhibit marked impairment of tumor necrosis factor alpha (TNF-α) secretion in response to S. enterica serovar Typhimurium infection. However, activation of extracellular growth factor-regulated kinase and NF-κB signaling pathways was relatively unaffected, as was increased expression of TNF-α mRNA. Furthermore, macrophage tolerance, which is associated with increased expression of the NF-κB p50 and p52 subunits, was induced by S. enterica serovar Typhimurium even in the absence of functional TLR4. These results indicate that during infection of macrophages by S. enterica serovar Typhimurium, TLR4 signals are required at a posttranscriptional step to maximize secretion of TNF-α. Signals delivered by pattern recognition receptors other than TLR4 are sufficient for the increased expression of the TNF-α transcript and at least some genes associated with macrophage tolerance.

scholarly journals CpxR regulates the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism

2020 ◽  
Vol 75 (10) ◽  
pp. 2780-2786 ◽  
Author(s):  
Ya-Jun Zhai ◽  
Hua-Run Sun ◽  
Xing-Wei Luo ◽  
Jian-Hua Liu ◽  
Yu-Shan Pan ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Colistin Resistance ◽  
Mobility Shift ◽  
Serovar Typhimurium ◽  
Electrophoretic Mobility Shift Assays ◽  
First Time ◽  
Signalling Systems

Abstract Background The two-component signalling systems PmrAB and PhoPQ of Salmonella have been extensively studied with regard to colistin resistance. We previously showed that overexpressed CpxR could significantly increase the colistin susceptibility (16-fold compared with the WT strain) of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) through PmrAB and PhoPQ. Objectives To identify the potential target genes of CpxR in PmrAB- and PhoPQ-related signalling pathways. Methods His6-CpxR was prokaryotically expressed and purified by Ni-NTA resin affinity chromatography. β-Galactosidase activity assays were conducted to investigate whether CpxR could regulate the promoters of colistin resistance-related genes (CRRGs). Electrophoretic mobility shift assays (EMSAs) were used to further detect His6-CpxR complexes with promoters of CRRGs. Results We demonstrated for the first time (to the best of our knowledge) that CpxR and the AcrAB–TolC efflux pump have reciprocal effects on CRRG transcription. Additionally, CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by binding directly to the promoters of phoPQ, pmrC, pmrH and pmrD at the CpxR box-like sequences or indirectly through other regulators including pmrAB and mgrB. Conclusions CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism.

scholarly journals Global transcriptional response of porcine mesenteric lymph nodes to Salmonella enterica serovar Typhimurium

Genomics ◽  
2007 ◽  
Vol 90 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Yanfang Wang ◽  
Long Qu ◽  
Jolita J. Uthe ◽  
Shawn M.D. Bearson ◽  
Daniel Kuhar ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Transcriptional Response ◽  
Mesenteric Lymph Nodes ◽  
Mesenteric Lymph ◽  
Serovar Typhimurium

Fate of Staphylococcus aureus, Salmonella enterica Serovar Typhimurium, and Vibrio vulnificus in Raw Oysters Treated with Chitosan

2006 ◽  
Vol 69 (7) ◽  
pp. 1600-1604 ◽  
Author(s):  
PALLAVI CHHABRA ◽  
YAO-WEN HUANG ◽  
JOSEPH F. FRANK ◽  
REVIS CHMIELEWSKI ◽  
KEITH GATES
Keyword(s):  
Staphylococcus Aureus ◽  
Hydrochloric Acid ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Vibrio Vulnificus ◽  
Storage Period ◽  
Major Effect ◽  
Chitosan Concentration ◽  
Serovar Typhimurium

The fate of Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio vulnificus in oysters treated with chitosan was investigated. Three concentrations (0.5, 1.0, and 2.0%) of chitosan in 0.5% hydrochloric acid were prepared and coated onto raw oysters, which were then stored at 4°C for 12 days. Untreated oysters and oysters coated with 0.5% hydrochloric acid without chitosan were used as controls. S. aureus cells were most sensitive to 2.0% chitosan followed by 0.5 and 1.0%. In general, chitosan treatment of oysters produced a decline in the population of S. aureus by 1 to 4 log CFU/ml compared with the untreated control. Chitosan treatment had no influence on the reduction of Salmonella Typhimurium over the 12-day storage period; inhibition of Salmonella Typhimurium growth was similar in both the control samples and the chitosan-treated samples. However, time of storage had a major effect on the survival of Salmonella Typhimurium on oysters. Neither time nor chitosan concentration had a significant effect on the growth of V. vulnificus during storage. All treatments were similar in inhibiting V. vulnificus growth.

scholarly journals The Multi-Copper-Ion Oxidase CueO of Salmonella enterica Serovar Typhimurium Is Required for Systemic Virulence

2010 ◽  
Vol 78 (5) ◽  
pp. 2312-2319 ◽  
Author(s):  
Maud E. S. Achard ◽  
Jai J. Tree ◽  
James A. Holden ◽  
Kim R. Simpfendorfer ◽  
Odilia L. C. Wijburg ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Copper Ions ◽  
Copper Ion ◽  
Mesenteric Lymph Nodes ◽  
E Coli ◽  
Significant Difference ◽  
Serovar Typhimurium ◽  
Branched Chain ◽  
Periplasmic Enzyme

ABSTRACT Salmonella enterica serovar Typhimurium possesses a multi-copper-ion oxidase (multicopper oxidase), CueO (also known as CuiD), a periplasmic enzyme known to be required for resistance to copper ions. CueO from S. Typhimurium was expressed as a recombinant protein in Escherichia coli, and the purified protein exhibited a high cuprous oxidase activity. We have characterized an S. Typhimurium cueO mutant and confirmed that it is more sensitive to copper ions. Using a murine model of infection, it was observed that the cueO mutant was significantly attenuated, as indicated by reduced recovery of bacteria from liver and spleen, although there was no significant difference in recovery from Peyer's patches and mesenteric lymph nodes. However, the intracellular survival of the cueO mutant in unprimed or gamma-interferon-primed murine macrophages was not statistically different from that of wild-type Salmonella, suggesting that additional host factors are involved in clearance of the cueO mutant. Unlike a cueO mutant from E. coli, the S. Typhimurium cueO mutant did not show greater sensitivity to hydrogen peroxide and its sensitivity to copper ions was not affected by siderophores. Similarly, the S. Typhimurium cueO mutant was not rescued from copper ion toxicity by addition of the branched-chain amino acids and leucine.

MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China

2019 ◽  
Vol 75 (1) ◽  
pp. 92-95 ◽  
Author(s):  
Qixia Luo ◽  
Fen Wan ◽  
Xiao Yu ◽  
Beiwen Zheng ◽  
Yunbo Chen ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Ecological Niches ◽  
Salmonella Infection ◽  
Serovar Typhimurium ◽  
Multiple Resistance Genes ◽  
Tn7 Transposition

Abstract Objectives Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before. Methods Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation. Results We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone. Conclusions To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

scholarly journals Colonization of Germ-Free Piglets with Mucinolytic and Non-Mucinolytic Bifidobacterium boum Strains Isolated from the Intestine of Wild Boar and Their Interference with Salmonella Typhimurium

2020 ◽  
Vol 8 (12) ◽  
pp. 2002
Author(s):  
Alla Splichalova ◽  
Radko Pechar ◽  
Jiri Killer ◽  
Zdislava Splichalova ◽  
Vera Neuzil Bunesova ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Cell Count ◽  
Inflammatory Cytokines ◽  
Bacterial Translocation ◽  
Foodborne Pathogens ◽  
Clinical Signs ◽  
Germ Free ◽  
Tnf Α ◽  
Mucin 2 ◽  
Gnotobiotic Piglet

Non-typhoidal Salmonella serovars are worldwide spread foodborne pathogens that cause diarrhea in humans and animals. Colonization of gnotobiotic piglet intestine with porcine indigenous mucinolytic Bifidobacterium boum RP36 strain and non-mucinolytic strain RP37 and their interference with Salmonella Typhimurium infection were compared. Bacterial interferences and impact on the host were evaluated by clinical signs of salmonellosis, bacterial translocation, goblet cell count, mRNA expression of mucin 2, villin, claudin-1, claudin-2, and occludin in the ileum and colon, and plasmatic levels of inflammatory cytokines IL-8, TNF-α, and IL-10. Both bifidobacterial strains colonized the intestine comparably. Neither RP36 nor RP37 B. boum strains effectively suppressed signs of salmonellosis. Both B. boum strains suppressed the growth of S. Typhimurium in the ileum and colon. The mucinolytic RP36 strain increased the translocation of S. Typhimurium into the blood, liver, and spleen.

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