Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC)
Project description:In response to the escalating challenge of antibiotic resistance, this study aims to explore novel antimicrobial agents, and we demonstrated that Laurocapram inhibits intracellular replication of Salmonella; to investigate its mechanism, we conducted RNA sequencing (RNA-seq) on murine macrophage-like RAW264.7 cells under four conditions: untreated control, Laurocapram treatment alone, Salmonella Typhimurium infection, and S. Typhimurium infection with concurrent Laurocapram treatment, with the goal of identifying key host genes and cellular pathways manipulated by the pathogen during infection and elucidating how Laurocapram counteracts Salmonella infection by modulating these targets.
Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC) Time course of comparative gene expression changes between log phase parental and adapted Enteritidis strains after 0, 10, 30 and 150 min of exposure to 50% of the respective MIC of DTAC.
Project description:Ribosome translates mRNAs by matching every 3-nucleotide sequence in mRNA, producing the appropriate proteins. As the amino acid sequence directly dictates the activity of the protein, frameshift often leads to unwanted effects. Here, we demonstrate that the intracellular pathogen Salmonella Typhimurium suppresses frameshift in the ugtL antimicrobial resistance gene during translation. This frameshift suppression is mediated by a ribosome pause occurring in a newly-identified overlapping gene, serving as a non-slip bump. Given that the pause site contains a poly-proline motif and can be resolved by elongation factor P, the removal of the ribosome pause by substituting the motif induces ribosome slippage in ugtL, resulting in nonfunctional UgtL frameshifted protein production. This renders Salmonella sensitive to antimicrobial peptides, indicating that elongation factor P-dependent ribosome pause is required for full antimicrobial resistance. These findings reveal a new regulatory mechanism of ribosome pause to ensure functional protein production by suppressing ribosome slippage-mediated frameshift.
Project description:Ribosome translates mRNAs by matching every 3-nucleotide sequence in mRNA, producing the appropriate proteins. As the amino acid sequence directly dictates the activity of the protein, frameshift often leads to unwanted effects. Here, we demonstrate that the intracellular pathogen Salmonella Typhimurium suppresses frameshift in the ugtL antimicrobial resistance gene during translation. This frameshift suppression is mediated by a ribosome pause occurring in a newly-identified overlapping gene, serving as a non-slip bump. Given that the pause site contains a poly-proline motif and can be resolved by elongation factor P, the removal of the ribosome pause by substituting the motif induces ribosome slippage in ugtL, resulting in nonfunctional UgtL frameshifted protein production. This renders Salmonella sensitive to antimicrobial peptides, indicating that elongation factor P-dependent ribosome pause is required for full antimicrobial resistance. These findings reveal a new regulatory mechanism of ribosome pause to ensure functional protein production by suppressing ribosome slippage-mediated frameshift.
2026-08-17 | GSE277235 | GEO
Project description:Antimicrobial resistance in foods
Project description:Multidrug-resistant (MDR; resistance to >3 antimicrobial classes) Salmonella enterica serovar I 4,[5],12:i:- strains were linked to a 2015 foodborne outbreak from pork. Strain USDA15WA-1, associated with the outbreak, harbors an MDR module and the metal tolerance element Salmonella Genomic Island 4 (SGI-4). Characterization of SGI-4 revealed that conjugational transfer of SGI-4 resulted in the mobile genetic element (MGE) replicating as a plasmid or integrating into the chromosome. Tolerance to copper, arsenic, and antimony compounds was increased in Salmonella strains containing SGI-4 compared to strains lacking the MGE. Following Salmonella exposure to copper, RNA-seq transcriptional analysis demonstrated significant differential expression of diverse genes and pathways, including induction of numerous metal tolerance genes (copper, arsenic, silver, and mercury). Evaluation of swine administered elevated concentrations of zinc oxide (2,000 mg/kg) and copper sulfate (200 mg/kg) as an antimicrobial feed additive (Zn+Cu) in their diet for 4 weeks prior to and 3 weeks post-inoculation with serovar I 4,[5],12:i:- indicated that Salmonella shedding levels declined at a slower rate in pigs receiving in-feed Zn+Cu compared to control pigs (no Zn+Cu). The presence of metal tolerance genes in MDR Salmonella serovar I 4,[5],12:i:- may provide benefits for environmental survival or swine colonization in metal-containing settings.