Project description:Staphylococcus aureus is a gram-positive cocci and an important human commensal bacteria and pathogen. S. aureus infections are increasingly difficult to treat because of the emergence of highly resistant MRSA (Methicillin-resistant S. aureus) strains. Here we present a method to study differential gene expression in S. aureus using high-throughput RNA-sequencing (RNA-seq). We use RNA-seq to examine the differential gene expression in S. aureus RN4220 cells containing an exogenously expressed transcription factor and between two S. aureus strains (RN4220 and NCTC8325-4). The information provided by RNA-seq was a significant advance over previously described microarray based techniques. We investigated the sequence and gene expression differences between RN4220 and NCTC8325-4 and used the RNA-seq data to identify S. aureus promoters suitable for in vitro analysis. We used RNA-seq to describe, on a genome wide scale, genes positively and negatively regulated by a phage encoded transcription factor, gp67. RNA-seq offers the ability to study differential gene expression with single-nucleotide resolution, and is a considerable improvement over the predominant genome-wide transcriptome technologies used in S. aureus.
Project description:To analyze function of three Two-component systems SAOUHSC_00184-185, SAOUHSC_01313-1314, and SAOUHSC_01980-1981, we have employed whole genome microarray expression profiling to identify genes transcription changed in respective mutant strains. Target TCSs were replaced by ermB gene. Cells were grown to OD600=2.0, and the RNA level of wild type NCTC8325 and three TCSs mutant were compared.
Project description:Staphylococcus aureus is a gram-positive cocci and an important human commensal bacteria and pathogen. S. aureus infections are increasingly difficult to treat because of the emergence of highly resistant MRSA (Methicillin-resistant S. aureus) strains. Here we present a method to study differential gene expression in S. aureus using high-throughput RNA-sequencing (RNA-seq). We use RNA-seq to examine the differential gene expression in S. aureus RN4220 cells containing an exogenously expressed transcription factor and between two S. aureus strains (RN4220 and NCTC8325-4). The information provided by RNA-seq was a significant advance over previously described microarray based techniques. We investigated the sequence and gene expression differences between RN4220 and NCTC8325-4 and used the RNA-seq data to identify S. aureus promoters suitable for in vitro analysis. We used RNA-seq to describe, on a genome wide scale, genes positively and negatively regulated by a phage encoded transcription factor, gp67. RNA-seq offers the ability to study differential gene expression with single-nucleotide resolution, and is a considerable improvement over the predominant genome-wide transcriptome technologies used in S. aureus. RNA-seq analysis of Staphylococcus aureus RN4220 (electrocompetent strain) carrying either empty pRMC2 (inducible expression vector) or pRMC2 carrying the ORF67 gene (encodes gp67). Both strains were grown to OD 0.2 and transgene expression was induced with 100ng/ml anhydrotetracycline. As a control, Staphylococcus aureus strain NCTC8325-4 (non-electrocompetent strain) was grown under identical conditions except without the addition of anhydrotetracycline.
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is problematic both in hospitals and the community. Currently, we have limited understanding of mechanisms of innate immune evasion used by S. aureus. To that end, we created an isogenic deletion mutant in strain MW2 (USA400) of the saeR/S two-component gene regulatory system and studied its role in mouse models of pathogenesis and during human neutrophil interaction. In this study, we demonstrate saeR/S plays a distinct role in S. aureus pathogenesis and is vital for virulence of MW2 in a mouse model of sepsis. Moreover, deletion of saeR/S significantly impaired survival of MW2 in human blood and after neutrophil phagocytosis. Microarray analysis of genes influenced by saeR/S demonstrated SaeR/S of MW2 influences a wide variety of genes with diverse biological functions. These data shed new insight into how virulence is regulated in S. aureus and associates a specific staphylococcal gene-regulatory system with invasive staphylococcal disease. Wild type control vs mutant at two different growth phases
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is problematic both in hospitals and the community. Currently, we have limited understanding of mechanisms of innate immune evasion used by S. aureus. To that end, we created an isogenic deletion mutant in strain MW2 (USA400) of the saeR/S two-component gene regulatory system and studied its role in mouse models of pathogenesis and during human neutrophil interaction. In this study, we demonstrate saeR/S plays a distinct role in S. aureus pathogenesis and is vital for virulence of MW2 in a mouse model of sepsis. Moreover, deletion of saeR/S significantly impaired survival of MW2 in human blood and after neutrophil phagocytosis. Microarray analysis of genes influenced by saeR/S demonstrated SaeR/S of MW2 influences a wide variety of genes with diverse biological functions. These data shed new insight into how virulence is regulated in S. aureus and associates a specific staphylococcal gene-regulatory system with invasive staphylococcal disease.