Project description:Staphylococcus aureus is a leading cause of hospital-associated infections. In addition, highly virulent strains of methicillin-resistant S. aureus (MRSA) are currently spreading outside health care settings. Survival in the human host is largely defined by the ability of S. aureus to resist mechanisms of innate host defense, of which antimicrobial peptides form a key part especially on epithelia and in neutrophil phagosomes. Here we demonstrate that the antimicrobial-peptide sensing system aps of the standard community-associated MRSA strain MW2 controls resistance to cationic antimicrobial peptides. The core of aps-controlled resistance mechanisms comprised the D-alanylation of teichoic acids (dlt operon), the incorporation of cationic lysyl-phosphatidylglycerol (L-PG) in the bacterial membrane (mprF), and the vraF/vraG putative antimicrobial peptide transporter. Further, the observed increased production of L-PG under the influence of cationic antimicrobial peptides was accompanied by the up-regulation of lysine biosynthesis. In noticeable difference to the aps system of S. epidermidis, only selected antimicrobial peptides strongly induced the aps response. Heterologous complementation with the S. epidermidis apsS gene indicated that this is likely caused by differences in the short extracellular loop of ApsS that interacts with the inducing antimicrobial peptide. Our study shows that the antimicrobial peptide sensor system aps is functional in the important human pathogen S. aureus, significant interspecies differences exist in the induction of the aps gene regulatory response, and aps inducibility is clearly distinguishable from effectiveness towards a given antimicrobial peptide. Keywords: Wild type control vs treated vs mutant Wild type untreated in triplicate is compared to wild type treated in triplicate along with three mutants in triplicate with and without treatment of indolicidin, totalling 30 samples
Project description:Staphylococcus aureus is a leading cause of hospital-associated infections. In addition, highly virulent strains of methicillin-resistant S. aureus (MRSA) are currently spreading outside health care settings. Survival in the human host is largely defined by the ability of S. aureus to resist mechanisms of innate host defense, of which antimicrobial peptides form a key part especially on epithelia and in neutrophil phagosomes. Here we demonstrate that the antimicrobial-peptide sensing system aps of the standard community-associated MRSA strain MW2 controls resistance to cationic antimicrobial peptides. The core of aps-controlled resistance mechanisms comprised the D-alanylation of teichoic acids (dlt operon), the incorporation of cationic lysyl-phosphatidylglycerol (L-PG) in the bacterial membrane (mprF), and the vraF/vraG putative antimicrobial peptide transporter. Further, the observed increased production of L-PG under the influence of cationic antimicrobial peptides was accompanied by the up-regulation of lysine biosynthesis. In noticeable difference to the aps system of S. epidermidis, only selected antimicrobial peptides strongly induced the aps response. Heterologous complementation with the S. epidermidis apsS gene indicated that this is likely caused by differences in the short extracellular loop of ApsS that interacts with the inducing antimicrobial peptide. Our study shows that the antimicrobial peptide sensor system aps is functional in the important human pathogen S. aureus, significant interspecies differences exist in the induction of the aps gene regulatory response, and aps inducibility is clearly distinguishable from effectiveness towards a given antimicrobial peptide. Keywords: Wild type control vs treated vs mutant
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen in both community and health care settings, which causes a wide range of infections. Its resistance to β-lactam antibiotics and methicillin in particular, greatly complicates treatment options and success rate due to the limited number of antibiotics with activity against MRSA. To further the development of alternative therapeutics, the mechanisms that mediate antibiotic resistance in MRSA need to be fully understood. Cannabinoid compounds including cannabidiol (CBD), tetrahydrocannabinol (THC) and cannabinol (CBN) have shown promise as potential antibiotic adjuvants. In the present study, MRSA cells were subjected to antibiotic stress from methicillin in combination with three cannabinoid compounds, and subsequently analysed using metaproteomics to assess the metabolic response. Subjecting MRSA to methicillin made the cells more viable and increased their energy production, as well as upregulation of penicillin-binding protein 2 (PBP2). The cannabinoids all showed antimicrobial activity against MRSA, and inhibited the energy production of the cells as well as PBP2 when used in combination with methicillin. Furthermore, all three cannabinoid compounds inhibited resistance mechanisms in MRSA, resulting in a decrease in the minimum inhibitory concentration (MIC) of methicillin when used in combination.
Project description:Staphylococcus aureus is a high-priority pathogen causing severe infections with high morbidity and mortality worldwide. Many S. aureus strains are methicillin-resistant (MRSA) or even multi-drug resistant. It is one of the most successful and prominent modern pathogens. An effective fight against S. aureus infections requires novel targets for antimicrobial and antistaphylococcal therapies. Recent advances in whole-genome sequencing and high-throughput techniques facilitate the generation of genome-scale metabolic models (GEMs). Among the multiple applications of GEMs is drug-targeting in pathogens. Hence, comprehensive and predictive metabolic reconstructions of S. aureus could facilitate the identification of novel targets for antimicrobial therapies. This review aims at giving an overview of all available GEMs of multiple S. aureus strains. We downloaded all 114 available GEMs of S. aureus for further analysis. The scope of each model was evaluated, including the number of reactions, metabolites, and genes.Furthermore, all models were quality-controlled using Mᴇᴍᴏᴛᴇ, an open-source application with standardized metabolic tests. Growth capabilities and model similarities were examined. This review should lead as a guide for choosing the appropriate GEM for a given research question. With the information about the availability, the format, and the strengths and potentials of each model, one can either choose an existing model or combine several models to create models with even higher predictive values. This facilitates model-driven discoveries of novel antimicrobial targets to fight multi-drug resistant S. aureus strains.
Project description:Staphylococcus aureus is a high-priority pathogen causing severe infections with high morbidity and mortality worldwide. Many S. aureus strains are methicillin-resistant (MRSA) or even multi-drug resistant. It is one of the most successful and prominent modern pathogens. An effective fight against S. aureus infections requires novel targets for antimicrobial and antistaphylococcal therapies. Recent advances in whole-genome sequencing and high-throughput techniques facilitate the generation of genome-scale metabolic models (GEMs). Among the multiple applications of GEMs is drug-targeting in pathogens. Hence, comprehensive and predictive metabolic reconstructions of S. aureus could facilitate the identification of novel targets for antimicrobial therapies. This review aims at giving an overview of all available GEMs of multiple S. aureus strains. We downloaded all 114 available GEMs of S. aureus for further analysis. The scope of each model was evaluated, including the number of reactions, metabolites, and genes. Furthermore, all models were quality-controlled using Mᴇᴍᴏᴛᴇ, an open-source application with standardized metabolic tests. Growth capabilities and model similarities were examined. This review should lead as a guide for choosing the appropriate GEM for a given research question. With the information about the availability, the format, and the strengths and potentials of each model, one can either choose an existing model or combine several models to create models with even higher predictive values. This facilitates model-driven discoveries of novel antimicrobial targets to fight multi-drug resistant S. aureus strains.
Project description:Staphylococcus aureus is a high-priority pathogen causing severe infections with high morbidity and mortality worldwide. Many S. aureus strains are methicillin-resistant (MRSA) or even multi-drug resistant. It is one of the most successful and prominent modern pathogens. An effective fight against S. aureus infections requires novel targets for antimicrobial and antistaphylococcal therapies. Recent advances in whole-genome sequencing and high-throughput techniques facilitate the generation of genome-scale metabolic models (GEMs). Among the multiple applications of GEMs is drug-targeting in pathogens. Hence, comprehensive and predictive metabolic reconstructions of S. aureus could facilitate the identification of novel targets for antimicrobial therapies. This review aims at giving an overview of all available GEMs of multiple S. aureus strains. We downloaded all 114 available GEMs of S. aureus for further analysis. The scope of each model was evaluated, including the number of reactions, metabolites, and genes.Furthermore, all models were quality-controlled using Mᴇᴍᴏᴛᴇ, an open-source application with standardized metabolic tests. Growth capabilities and model similarities were examined. This review should lead as a guide for choosing the appropriate GEM for a given research question. With the information about the availability, the format, and the strengths and potentials of each model, one can either choose an existing model or combine several models to create models with even higher predictive values. This facilitates model-driven discoveries of novel antimicrobial targets to fight multi-drug resistant S. aureus strains.
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:Methicillin-resistant Staphylococcus aureus (MRSA) infections result in more than 200,000 hospitalizations and 10,000 deaths in the United States each year and remain an important medical challenge. To better understand the transcriptome of Staphylococcus aureus USA300 NRS384, a community-acquired MRSA strain, we have conducted an RNA-Seq experiment on WT samples.
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. sodium houttuyfonate 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 sodium houttuyfonate. Keywords: gene expression array-based, count
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