Impact of yihO/Q deletion in O-Antigen capsule formation, environmental stress mitigation, and intracellular virulence, survival and replication of Salmonella Typhimurium
Ontology highlight
ABSTRACT:
ORGANISM(S): Salmonella enterica subsp. enterica serovar Typhimurium
PROVIDER: GSE272846 | GEO | 2024/08/07
REPOSITORIES: GEO
Similar Datasets
Project description:Salmonella must express and deploy a type III secretion system located in Salmonella pathogenicity island 2 (SPI-2) in order to survive in host phagocytic vacuoles and to cause systemic infection in mouse models of typhoid fever. A genome-wide approach to screening for Salmonella genes that are transcriptionally co-regulated in vitro with SPI-2 genes was used to identify bacterial loci that might function in a mouse model of systemic disease. Strains with mutations in three SPI-2 co-expressed genes were constructed and tested for their ability to cause disease in mice. We found that virK, a homologue of a Shigella virulence determinant, and rcsC, a sensor kinase, are important at late stages of infection. A second Salmonella gene that has VirK homology, somA, is also important for systemic infection in mice. We have shown that expression of both virK and somA requires the transcription factor PhoP, whereas rcsC does not. Additionally, rcsC expression does not require the transcription factor OmpR, but expression of one of the known targets of RcsC, the yojN rcsB putative operon, does require OmpR. virK, somA and rcsC are expressed in tissue culture macrophages and confer Salmonella resistance to the cationic peptide polymyxin B. We conclude that virK, somA and rcsC are important for late stages of Salmonella enteric fever, and that they probably contribute to the remodelling of the bacterial outer membrane in response to the host environment.
2005-10-07 | E-SMDB-1981 | biostudies-arrayexpress
Project description:Salmonella must express and deploy a type III secretion system located in Salmonella pathogenicity island 2 (SPI-2) in order to survive in host phagocytic vacuoles and to cause systemic infection in mouse models of typhoid fever. A genome-wide approach to screening for Salmonella genes that are transcriptionally co-regulated in vitro with SPI-2 genes was used to identify bacterial loci that might function in a mouse model of systemic disease. Strains with mutations in three SPI-2 co-expressed genes were constructed and tested for their ability to cause disease in mice. We found that virK, a homologue of a Shigella virulence determinant, and rcsC, a sensor kinase, are important at late stages of infection. A second Salmonella gene that has VirK homology, somA, is also important for systemic infection in mice. We have shown that expression of both virK and somA requires the transcription factor PhoP, whereas rcsC does not. Additionally, rcsC expression does not require the transcription factor OmpR, but expression of one of the known targets of RcsC, the yojN rcsB putative operon, does require OmpR. virK, somA and rcsC are expressed in tissue culture macrophages and confer Salmonella resistance to the cationic peptide polymyxin B. We conclude that virK, somA and rcsC are important for late stages of Salmonella enteric fever, and that they probably contribute to the remodelling of the bacterial outer membrane in response to the host environment. Groups of assays that are related as part of a time series. Computed
2005-12-02 | E-GEOD-3735 | biostudies-arrayexpress
Project description:Salmonella must express and deploy a type III secretion system located in Salmonella pathogenicity island 2 (SPI-2) in order to survive in host phagocytic vacuoles and to cause systemic infection in mouse models of typhoid fever. A genome-wide approach to screening for Salmonella genes that are transcriptionally co-regulated in vitro with SPI-2 genes was used to identify bacterial loci that might function in a mouse model of systemic disease. Strains with mutations in three SPI-2 co-expressed genes were constructed and tested for their ability to cause disease in mice. We found that virK, a homologue of a Shigella virulence determinant, and rcsC, a sensor kinase, are important at late stages of infection. A second Salmonella gene that has VirK homology, somA, is also important for systemic infection in mice. We have shown that expression of both virK and somA requires the transcription factor PhoP, whereas rcsC does not. Additionally, rcsC expression does not require the transcription factor OmpR, but expression of one of the known targets of RcsC, the yojN rcsB putative operon, does require OmpR. virK, somA and rcsC are expressed in tissue culture macrophages and confer Salmonella resistance to the cationic peptide polymyxin B. We conclude that virK, somA and rcsC are important for late stages of Salmonella enteric fever, and that they probably contribute to the remodelling of the bacterial outer membrane in response to the host environment. Groups of assays that are related as part of a time series. Keywords: time_series_design
2005-12-03 | GSE3735 | GEO
Project description:Global expression profiles of Salmonella typhi grown in the supernatant of infection and within human macrophages at 0h, 2h, 8h and 24h were obtained. Stringent analytical methods were used to compare Salmonella typhi cDNAs and revealed that known virulence factors, such as the SPI-1 and SPI-2 encoded type III secretion systems, were found to be expressed as predicted during infection by Salmonella. Intracellular Typhi expressed many genes encoding antimicrobial peptides, used the glyoxylate bypass for fatty acid utilization, and, did not induce the SOS response or the oxidative stress response. Genes coding for the flagellar apparatus, chemotaxis and the iron transport system were down-regulated in vivo. The combined use of SCOTS and microarray is an effective way to determine global bacterial gene expression profiling in the context of host infection, without the need of increasing the multiplicity of infection beyond what is seen in nature. Keywords: Time course
2006-01-10 | GSE3096 | GEO
Project description:Recombinant attenuated Salmonella are believed to act as powerful live vaccine carrier able to elicit protection against many infectious agents. ∆aroA exhibits auxotrophy for aromatic amino acids and is commonly used for attenuation. Interestingly, deletion of aroA dramatically increased virulence of the Salmonella. Detailed analyses demonstrate that Salmonella’s physiology is significantly altered, most likely due to osmotic imbalance and stress. The result is a serious influence of lipid and amino acid turn over, possible increasing sensitivity to penicillin, complement and phagocytic uptake. In addition, in concert with other immunomodulating mutations, the phase of flagella expression is changed. Furthermore, virulence associated genes like arnT or ansB were affected. These alterations could explain the increased virulence. Thus, intravenous application of ∆aroA Salmonella to mice significantly increased induction of pro-inflammatory cytokines. We also employed such bacteria in therapy against tumors and realized that ∆aroA strains display an improved anti-tumor activity.
2016-08-09 | GSE74433 | GEO
Project description:FinO-domain proteins such as ProQ of the model pathogen Salmonella enterica have emerged as a new class of major RNA-binding proteins in bacteria. ProQ has been shown to target hundreds of transcripts including mRNAs from many virulence regions but its role, if any, in bacterial pathogenesis has not been studied. Here, using a Dual RNA-seq approach to profile ProQ-dependent gene expression changes as Salmonella infects human cells, we reveal dysregulation of bacterial motility, chemotaxis and virulence genes which is accompanied by altered mitogen-activated protein kinase signaling in the host. Comparison with Hfq, Salmonella’s other major RNA chaperone, reinforces the notion that these two global RNA binding proteins work in parallel to ensure full virulence. Of newly discovered infection-associated ProQ-bound small noncoding RNAs, we show that STnc540 represses a virulence-related magnesium transporter mRNA in a ProQ-dependent manner. Together, this comprehensive study uncovers the relevance of ProQ for Salmonella infection and highlights the importance of RNA-binding proteins in regulating bacterial virulence programs.
2018-11-28 | GSE117255 | GEO
Project description:FinO-domain proteins such as ProQ of the model pathogen Salmonella enterica have emerged as a new class of major RNA-binding proteins in bacteria. ProQ has been shown to target hundreds of transcripts including mRNAs from many virulence regions but its role, if any, in bacterial pathogenesis has not been studied. Here, using a Dual RNA-seq approach to profile ProQ-dependent gene expression changes as Salmonella infects human cells, we reveal dysregulation of bacterial motility, chemotaxis and virulence genes which is accompanied by altered mitogen-activated protein kinase signaling in the host. Comparison with Hfq, Salmonella’s other major RNA chaperone, reinforces the notion that these two global RNA binding proteins work in parallel to ensure full virulence. Of newly discovered infection-associated ProQ-bound small noncoding RNAs, we show that STnc540 represses a virulence-related magnesium transporter mRNA in a ProQ-dependent manner. Together, this comprehensive study uncovers the relevance of ProQ for Salmonella infection and highlights the importance of RNA-binding proteins in regulating bacterial virulence programs.
2018-11-28 | GSE117252 | GEO
Project description:FinO-domain proteins such as ProQ of the model pathogen Salmonella enterica have emerged as a new class of major RNA-binding proteins in bacteria. ProQ has been shown to target hundreds of transcripts including mRNAs from many virulence regions but its role, if any, in bacterial pathogenesis has not been studied. Here, using a Dual RNA-seq approach to profile ProQ-dependent gene expression changes as Salmonella infects human cells, we reveal dysregulation of bacterial motility, chemotaxis and virulence genes which is accompanied by altered mitogen-activated protein kinase signaling in the host. Comparison with Hfq, Salmonella’s other major RNA chaperone, reinforces the notion that these two global RNA binding proteins work in parallel to ensure full virulence. Of newly discovered infection-associated ProQ-bound small noncoding RNAs, we show that STnc540 represses a virulence-related magnesium transporter mRNA in a ProQ-dependent manner. Together, this comprehensive study uncovers the relevance of ProQ for Salmonella infection and highlights the importance of RNA-binding proteins in regulating bacterial virulence programs.
2018-11-28 | GSE117236 | GEO
Project description:LeuO, initially identified as a leucine regulator in Escherichia coli, has since been identified as a global regulator required for bacterial pathogenicity in a broad range of bacteria, including gram-negative pathogens, such as Salmonella, Shigella, and Vibrio; and gram-positive bacteria, such as Streptococcus pneumoniae. However, the regulatory roles and targets of LeuO vary among species. In the Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium), LeuO represses the transcription of Salmonella pathogenicity island (SPI)-1, thus diminishing the ability of the bacteria to invade host cells. However, its regulatory effect on SPI-2, essential for survival within macrophages, remains poorly understood. This study aimed to determine the regulatory role of LeuO in the intracellular persistence of S. Typhimurium. Overexpression of LeuO repressed the transcription of SPI-2 genes and accordingly decreased its protein levels. Chromatin immunoprecipitation sequencing revealed the genome-wide binding sites of LeuO in S. Typhimurium 14028 and identified a distinctive 23-nucleotide motif with high similarity to that previously discovered in E. coli. Notably, multiple LeuO-binding sites were predicted within SPI-2, primarily adjacent to the ssrA and ssrB loci. In vitro binding assays verified the high binding affinity between LeuO and three specific motifs located at positions -35 to -12 (ssrA1),+231 to +254 (ssrA2) near ssrA, and at positions -622 to -599 (ssrB3) near ssrB, relative to their transcription start sites. Furthermore, LeuO overexpression abolished the transcription of lacZ fused to the ssrA promoter containing ssrA1 and ssrA2, suggesting the direct repression of ssrA via LeuO-binding. The absence of LeuO increased the intracellular survival of S. Typhimurium within macrophages, whereas its overexpression attenuated bacterial persistence, which was presumably associated with the downregulation of SPI-2 by LeuO. This study reveals the versatile regulatory mechanisms of LeuO and underscores its pivotal role in modulating SPI-2 expression, thereby providing key insights into the fine tuning of virulence by Salmonella during systemic infection.
2024-11-14 | GSE280231 | GEO
Project description:<p><em>Salmonella Typhimurium</em> establishes systemic infection by replicating in host macrophages. Here we show that macrophages infected with <em>S. Typhimurium</em> exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates. The effects on serine synthesis are mediated by bacterial protein SopE2, a type III secretion system (T3SS) effector encoded in pathogenicity island SPI-1. The changes in host metabolism promote intracellular replication of <em>S. Typhimurium</em> via two mechanisms: decreased glucose levels lead to upregulated bacterial uptake of 2- and 3-phosphoglycerate and phosphoenolpyruvate (carbon sources), while increased pyruvate and lactate levels induce upregulation of another pathogenicity island, SPI-2, known to encode virulence factors. Pharmacological or genetic inhibition of host glycolysis, activation of host serine synthesis, or deletion of either the bacterial transport or signal sensor systems for those host glycolytic intermediates impairs <em>S. Typhimurium</em> replication or virulence.</p>
2024-05-22 | MTBLS2347 | MetaboLights