Dataset Information

Staphylococcus aureus biofilm organization modulated by YycFG two-component regulatory pathway.

ABSTRACT: BACKGROUND:Staphylococcus aureus (S. aureus) infection accounts for more than 50% of the osteomyelitis cases. Currently, methicillin-resistant S. aureus (MRSA) strains present an urgent medical problem. The YycFG two-component regulatory system (TCS) can allow bacteria to rapidly adapt to physical, chemical, and biological stresses. To define the role of YycFG in modulation virulence of S. aureus in osteomyelitis, we isolated clinical MRSA strains and compared these with ATCC29213 methicillin-sensitive S. aureus (MSSA). METHODS:In the present study, 13 MRSA strains from chronic osteomyelitis tissues were isolated. The in-depth sequencing of 16S rRNA amplicons of the samples was conducted. Bacterial growth was monitored, and biofilm biomass was determined by crystal violet microtiter assay. Furthermore, quantitative RT-PCR analysis was adopted to identify the expression of yycF/G/H and icaA/D in MRSA and MSSA strains. Analysis of variance with one-way ANOVA was used for statistical analysis. RESULTS:The in-depth sequencing of 16S rRNA amplicons of the clinical samples indicated a polymicrobial infection, with the phylum Firmicutes made up 13% of the microbial population. The MRSA strains showed an accelerated growth rate compared to the MSSA strains. Of note, MRSA biofilms showed an accumulation of an intercellular polysaccharides matrix and enhanced biomass upon microscopic examination. Furthermore, MRSA strains had a higher expression of the yycF/G/H and icaA/D genes and adhesion force. CONCLUSIONS:These data suggested the roles of intercellular polysaccharide in S. aureus pathogenesis, indicating a possible association between YycFG pathways and MRSA strain virulence.

SUBMITTER: Wu S

PROVIDER: S-EPMC6325680 | biostudies-other | 2019 Jan

REPOSITORIES: biostudies-other

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Staphylococcus aureus biofilm organization modulated by YycFG two-component regulatory pathway.

Wu Shizhou S Huang Fuguo F Zhang Hui H Lei Lei L

Journal of orthopaedic surgery and research 20190108 1

<h4>Background</h4>Staphylococcus aureus (S. aureus) infection accounts for more than 50% of the osteomyelitis cases. Currently, methicillin-resistant S. aureus (MRSA) strains present an urgent medical problem. The YycFG two-component regulatory system (TCS) can allow bacteria to rapidly adapt to physical, chemical, and biological stresses. To define the role of YycFG in modulation virulence of S. aureus in osteomyelitis, we isolated clinical MRSA strains and compared these with ATCC29213 methic ...[more]

PMID: 30621792

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Project description:Staphylococcus lugdunensis is a coagulase negative Staphylococcus recognized as a virulent pathogen. It is responsible for a wide variety of infections, some of which are associated with biofilm production, such as implanted medical device infections or endocarditis. However, little is known about S. lugdunensis regulation of virulence factor expression. Two-component regulatory systems (TCS) play a critical role in bacterial adaptation, survival, and virulence. Among them, LytSR is widely conserved but has variable roles in different organisms, all connected to metabolism or cell death and lysis occurring during biofilm development. Therefore, we investigated here the functions of LytSR in S. lugdunensis pathogenesis. Deletion of lytSR in S. lugdunensis DSM 4804 strain did not alter either susceptibility to Triton X-100 induced autolysis or death induced by antibiotics targeting cell wall synthesis. Interestingly, ΔlytSR biofilm was characterized by a lower biomass, a lack of tower structures, and a higher rate of dead cells compared to the wild-type strain. Virulence toward Caenorhabditis elegans using a slow-killing assay was significantly reduced for the mutant compared to the wild-type strain. By contrast, the deletion of lytSR had no effect on the cytotoxicity of S. lugdunensis toward the human keratinocyte cell line HaCaT. Transcriptional analyses conducted at mid- and late-exponential phases showed that lytSR deletion affected the expression of 286 genes. Most of them were involved in basic functions such as the metabolism of amino acids, carbohydrates, and nucleotides. Furthermore, LytSR appeared to be involved in the regulation of genes encoding known or putative virulence and colonization factors, including the fibrinogen-binding protein Fbl, the major autolysin AtlL, and the type VII secretion system. Overall, our data suggest that the LytSR TCS is implicated in S. lugdunensis pathogenesis, through its involvement in biofilm formation and potentially by the control of genes encoding putative virulence factors.

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Project description:Staphylococcus lugdunensis is a coagulase negative Staphylococcus, recognized as a virulent pathogen. It is responsible for a wide variety of infections, some of which being associated with biofilm production, such as implanted medical devices infections or endocarditis. However, little is known about S. lugdunensis virulence regulation. Two-component regulatory systems (TCS) play critical roles in bacterial adaptation, survival and virulence. Among them, LytSR is widely conserved, but has variable roles in different organisms, all being connected to metabolism or cell death and lysis into biofilms. Therefore, we investigated here the functions of LytSR in S. lugdunensis pathogenesis. Deletion of lytSR in S. lugdunensis DSM 4804 strain did not alter neither the susceptibility to Triton X-100 induced autolysis nor the death induced by antibiotics targeting cell wall synthesis. Interestingly, ΔlytSR biofilm was characterized by a lower biomass, a lack of tower structures and a higher rate of dead cells compared to the wild-type strain. Virulence towards Caenorhabditis elegans using slow-killing assay was significantly reduced for the mutant compared to the wild-type strain. In contrast, the deletion of lytSR had no effect on S. lugdunensis cytotoxicity towards the human keratinocyte cell line HaCaT. Transcriptional analyses conducted at mid- and late-exponential phases showed that lytSR deletion affected the expression of 286 genes. Most of them were involved in basic functions such as metabolism of amino acid, carbohydrates and nucleotides. Furthermore, LytSR appeared to be involved in the regulation of genes coding known or putative virulence and colonization factors, including the fibrinogen-binding protein Fbl, the major autolysin AtlL and the type VII secretion system. Overall, our data suggest that LytSR TCS is implicated in S. lugdunensis pathogenesis, through its involvement in biofilm formation and potentially by the control of genes encoding putative virulence factors.

Dataset Information

Staphylococcus aureus biofilm organization modulated by YycFG two-component regulatory pathway.

Publications

Staphylococcus aureus biofilm organization modulated by YycFG two-component regulatory pathway.

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