Project description:Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Here, we report the analysis of the transcriptome of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes represents metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of main virulence associated genes or known human colonization factors. Here, we document regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vwbp, located on SaPIbov5). Colonization with isogenic-deletion strains (Δvwbp and ΔscpA) did not alter the nasal S. aureus colonization compared to wild type. Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation.
Project description:Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Here, we report the analysis of the transcriptome of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes represents metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of main virulence associated genes or known human colonization factors. Here, we document regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vwbp, located on SaPIbov5). Colonization with isogenic-deletion strains (Î?vwbp and Î?scpA) did not alter the nasal S. aureus colonization compared to wild type. Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Number of the samples: 5 (timepoint 0 min, 30 min, 60 min, 90 min and 180 min) in 4 replicates. 4 control samples
Project description:Defects in innate immunity affect many different physiologic systems and several studies of patients with primary immunodeficiency disorders demonstrated the importance of innate immune system components in disease prevention or colonization of bacterial pathogens. To assess the role of the innate immune system on nasal colonization with Staphylococcus aureus, innate immune responses in pediatric S. aureus nasal persistent carriers (n=3) and non-carriers (n=3) were profiled by RNAseq. We stimulated previously frozen peripheral blood mononuclear cells (PBMCs) from these subjects with i) live S. aureus (a mixture of all carriage isolates), or ii) heat-killed S. aureus.PBMC gene expression profiles differed between persistent and non-S. aureus carriers following stimulation with either live or dead S. aureus. These observations suggest that individuals susceptible to persistent carriage with S. aureus may possess differences in their live/dead bacteria recognition pathway and that innate pathway signaling is different between persistent and non-carriers of S. aureus.
Project description:Nasal colonization is well described; however, we have limited knowledge about S. aureus throat colonization. The main objective of this project was to explore differentially expressed genes (DEGs) in S. aureus throat isolate TR145 exposed for 1 or 3 hours (h) to human tonsil epithelial cells (HTEpiC) by using RNA sequencing (RNA-seq) and pathway analysis. We have shown the suitability of using HTEpiC as an in vitro model for investigating key determinants in S. aureus during co-incubation with the HTEpiC cells. Among the DEGs were genes encoding proteins involved in adhesion and immune evasion, as well as iron acquisition and transport. As their expression is induced upon meeting with the HTEpiC, they might be explored further for future targets for intervention to prevent either colonization or infection in the throat region.
Project description:Staphylococcus aureus (S. aureus) has already to be one of the most commonly identified bacteria that cause food poisoning. S. aureus colonization in humans can cause serious infections, toxinoses and life threatening diseases. The bacteriocin nisin has been extensively used as potential natural preservative in the food industry, but the overall transcriptional response mechanisms of S. aureus to nisin are still poorly understood. To detect the possible molecular mechanism of nisin against S. aureus, Affymetrix GeneChips were used to determine the global comparative transcription of S. aureus cells triggered by treatment with sub-inhibitory concentrations of nisin. Staphylococcus aureus planktonic cells were exposed for 60 minutes to nisin at concentration of 4 M-NM-<g/ml (1/2M-CM-^W MIC). 2 samples including 2 control samples are analyzed.
Project description:MepR is a substrate-responsive repressor of mepR and mepA, which encode itself and a MATE family multidrug efflux pump. Microarray analyses of Staphylococcus aureus SH1000 and its mepR-disrupted derivative revealed changes in expression of many genes in addition to mepR and mepA, notably several involved in virulence Keywords: Staphylococcus aureus, MATE efflux pump, MepR
Project description:Staphylococcus aureus (S. aureus) has already to be one of the most commonly identified bacteria that cause food poisoning. S. aureus colonization in humans can cause serious infections, toxinoses and life threatening diseases. The bacteriocin nisin has been extensively used as potential natural preservative in the food industry, but the overall transcriptional response mechanisms of S. aureus to nisin are still poorly understood. To detect the possible molecular mechanism of nisin against S. aureus, Affymetrix GeneChips were used to determine the global comparative transcription of S. aureus cells triggered by treatment with sub-inhibitory concentrations of nisin.
Project description:Staphylococcus aureus is one of the most important pathogens in humans and animals, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Rhein, a natural plant product, has potential antimicrobial activity against Staphylococcus aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with rhein. Results provided insight into mechanisms involved in rhein - Staphylococcus aureus interactions. Keywords: rhein response
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. magnolol has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with magnolol. Keywords: gene expression array-based, count
Project description:USA300 Staphylococcus aureus is responsible for the current outbreak of skin abscesses in the United States. Unlike other USA types, USA300 colonizes the rectum at rates higher than the nose. The reason for the difference in colonization site preference may be related to specific adherence or attachment factors contained in the genome of these strains. Additional knowledge in this field may help design novel prophylactic and therapeutic strategies to combat staphylococcal infections. Strains of USA300 MSSA and MRSA colonizing the nose and/or rectum from children with staphylococcal skin abscesses were compared by whole genome array technology to identify bacterial genetic determinants associated with site-specific colonization. Strains isolated from different colonization sites were indistinguishable by genomic content. Site-specific colonization traits were not detected in the colonizing bacteria by this array. Either host characteristics associated with staphylococcal carriage or under represented bacterial genomic constructions need to be examined to determine the etiology of this site-specific colonization. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-102 target=_blank>BuG@Sbase</a>