Copper Stress Induces a Global Stress Response in Staphylococcus aureus and Represses sae and agr Expression and Biofilm Formation

ABSTRACT Copper is an important cofactor for many enzymes; however, high levels of copper are toxic. Therefore, bacteria must ensure there is sufficient copper for use as a cofactor but, more importantly, must limit free intracellular levels to prevent toxicity. In this study, we have used DNA microarray to identify Staphylococcus aureus copper-responsive genes. Transcriptional profiling of S. aureus SH1000 grown in excess copper identified a number of genes which fall into four groups, suggesting that S. aureus has four main mechanisms for adapting to high levels of environmental copper, as follows: (i) induction of direct copper homeostasis mechanisms; (ii) increased oxidative stress resistance; (iii) expression of the misfolded protein response; and (iv) repression of a number of transporters and global regulators such as Agr and Sae. Our experimental data confirm that resistance to oxidative stress and particularly to H2O2 scavenging is an important S. aureus copper resistance mechanism. Our previous studies have demonstrated that Eap and Emp proteins, which are positively regulated by Agr and Sae, are required for biofilm formation under low-iron growth conditions. Our transcriptional analysis has confirmed that sae, agr, and eap are repressed under high-copper conditions and that biofilm formation is indeed repressed under high-copper conditions. Therefore, our results may provide an explanation for how copper films can prevent biofilm formation on catheters.

Download Full-text

Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

Infection and Immunity ◽

10.1128/iai.69.6.4079-4085.2001 ◽

2001 ◽

Vol 69 (6) ◽

pp. 4079-4085 ◽

Cited By ~ 222

Author(s):

Sarah E. Cramton ◽

Martina Ulrich ◽

Friedrich Götz ◽

Gerd Döring

Keyword(s):

Staphylococcus Aureus ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Extracellular Polysaccharide ◽

Growth Conditions ◽

Anaerobic Conditions ◽

Anaerobic Environment ◽

Specific Mrna

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.

Download Full-text

Investigating the Transcriptome of Candida albicans in a Dual-Species Staphylococcus aureus Biofilm Model

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.791523 ◽

2021 ◽

Vol 11 ◽

Author(s):

Bryn Short ◽

Christopher Delaney ◽

Emily McKloud ◽

Jason L. Brown ◽

Ryan Kean ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Candida Albicans ◽

Biofilm Formation ◽

Driving Forces ◽

Transcriptional Profiling ◽

Specific Interaction ◽

Opportunistic Pathogen ◽

Virulence Proteins ◽

Biofilm Model ◽

Upregulated Genes

Candida albicans is an opportunistic pathogen found throughout multiple body sites and is frequently co-isolated from infections of the respiratory tract and oral cavity with Staphylococcus aureus. Herein we present the first report of the effects that S. aureus elicits on the C. albicans transcriptome. Dual-species biofilms containing S. aureus and C. albicans mutants defective in ALS3 or ECE1 were optimised and characterised, followed by transcriptional profiling of C. albicans by RNA-sequencing (RNA-seq). Altered phenotypes in C. albicans mutants revealed specific interaction profiles between fungus and bacteria. The major adhesion and virulence proteins Als3 and Ece1, respectively, were found to have substantial effects on the Candida transcriptome in early and mature biofilms. Despite this, deletion of ECE1 did not adversely affect biofilm formation or the ability of S. aureus to interact with C. albicans hyphae. Upregulated genes in dual-species biofilms corresponded to multiple gene ontology terms, including those attributed to virulence, biofilm formation and protein binding such as ACE2 and multiple heat-shock protein genes. This shows that S. aureus pushes C. albicans towards a more virulent genotype, helping us to understand the driving forces behind the increased severity of C. albicans-S. aureus infections.

Download Full-text

Expression of icaA and icaD genes in biofilm formation in Staphylococcus aureus isolates from bovine subclinical mastitis

Pesquisa Veterinária Brasileira ◽

10.1590/1678-5150-pvb-6645 ◽

2021 ◽

Vol 41 ◽

Author(s):

Viviane F. Marques ◽

Huarrisson A. Santos ◽

Thomas H. Santos ◽

Dayanne A. Melo ◽

Shana M.O. Coelho ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Phenotypic Expression ◽

Bovine Mastitis ◽

Subclinical Mastitis ◽

Transcriptional Analysis ◽

Important Species ◽

High Prevalence ◽

Staphylococcus Spp

ABSTRACT: Staphylococcus spp. plays a significant role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most important species due to the high prevalence and the difficulty of in vivo treatment that is related to the expression of virulence factors and biofilm formation. This study aimed to detect the phenotypic expression of the biofilm formation in 20 S. aureus isolated from bovine mastitis and to evaluate the expression and regulation of genes involved in its production. MALDI-TOF and phenogenotypic identification assays were performed to characterize the isolates. The phenotypic biofilm production and the presence of icaA and icaD and bap genes were evaluated. The Agr system was typified (agr I, agr II, agr III and agr IV) and its regulator (agr RNAIII) was detected. Furtherly, Real-time PCR (qPCR) was performed at chosen times to quantify the expression of icaA, icaD and hld genes in three selected isolates. All 20 strains were biofilm producers and most presented icaA and icaD genes. Only one isolate presented the bap gene. The agr gene type II showed a prevalence of 70%. Transcriptional analysis revealed increased expression of ica genes at eight hours of growth. These results confirm that polysaccharides production mediated by the icaADBC operon genes is an essential mechanism to the biofilm formation and contributes to the early stages of bacterial growth.

Download Full-text

PYED-1 Inhibits Biofilm Formation and Disrupts the Preformed Biofilm of Staphylococcus aureus

Antibiotics ◽

10.3390/antibiotics9050240 ◽

2020 ◽

Vol 9 (5) ◽

pp. 240 ◽

Cited By ~ 1

Author(s):

Adriana Vollaro ◽

Anna Esposito ◽

Eliana Pia Esposito ◽

Raffaele Zarrilli ◽

Annalisa Guaragna ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Quorum Sensing ◽

Biofilm Formation ◽

Surface Proteins ◽

Transcriptional Analysis ◽

Capsular Polysaccharides ◽

Dependent Manner ◽

Chronic Infections ◽

Concentration Dependent Manner ◽

Expression Of Genes

Pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1 (PYED-1), a heterocyclic corticosteroid derivative of deflazacort, exhibits broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria. Here, we investigated the effect of PYED-1 on the biofilms of Staphylococcus aureus, an etiological agent of biofilm-based chronic infections such as osteomyelitis, indwelling medical device infections, periodontitis, chronic wound infections, and endocarditis. PYED-1 caused a strong reduction in biofilm formation in a concentration dependent manner. Furthermore, it was also able to completely remove the preformed biofilm. Transcriptional analysis performed on the established biofilm revealed that PYED-1 downregulates the expression of genes related to quorum sensing (agrA, RNAIII, hld, psm, and sarA), surface proteins (clfB and fnbB), secreted toxins (hla, hlb, and lukD), and capsular polysaccharides (capC). The expression of genes that encode two main global regulators, sigB and saeR, was also significantly inhibited after treatment with PYED-1. In conclusion, PYED-1 not only effectively inhibited biofilm formation, but also eradicated preformed biofilms of S. aureus, modulating the expression of genes related to quorum sensing, surface and secreted proteins, and capsular polysaccharides. These results indicated that PYED-1 may have great potential as an effective antibiofilm agent to prevent S. aureus biofilm-associated infections.

Download Full-text

The Posttranslocational Chaperone Lipoprotein PrsA Is Involved in both Glycopeptide and Oxacillin Resistance in Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06264-11 ◽

2012 ◽

Vol 56 (7) ◽

pp. 3629-3640 ◽

Cited By ~ 38

Author(s):

Ambre Jousselin ◽

Adriana Renzoni ◽

Diego O. Andrey ◽

Antoinette Monod ◽

Daniel P. Lew ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Cell Wall ◽

Wall Stress ◽

Growth Conditions ◽

Transcriptional Analysis ◽

Pharmacological Intervention ◽

Content Type ◽

Cell Wall Stress ◽

Oxacillin Resistance ◽

Mrsa Strains

ABSTRACTUnderstanding in detail the factors which permitStaphylococcus aureusto counteract cell wall-active antibiotics is a prerequisite to elaborating effective strategies to prolong the usefulness of these drugs and define new targets for pharmacological intervention. Methicillin-resistantS. aureus(MRSA) strains are major pathogens of hospital-acquired and community-acquired infections and are most often treated with glycopeptides (vancomycin and teicoplanin) because of their resistance to most penicillins and a limited arsenal of clinically proven alternatives. In this study, we examined PrsA, a lipid-anchored protein of the parvulin PPIase family (peptidyl-prolylcis/transisomerase) found ubiquitously in all Gram-positive species, in which it assists posttranslocational folding at the outer surface of the cytoplasmic membrane. We show by both genetic and biochemical assays thatprsAis directly regulated by the VraRS two-component sentinel system of cell wall stress. Disruption ofprsAis tolerated byS. aureus, and its loss results in no detectable overt macroscopic changes in cell wall architecture or growth rate under nonstressed growth conditions. Disruption ofprsAleads, however, to notable alterations in the sensitivity to glycopeptides and dramatically decreases the resistance of COL (MRSA) to oxacillin. Quantitative transcriptional analysis reveals thatprsAandvraRare coordinately upregulated in a panel of stable laboratory and clinical glycopeptide-intermediateS. aureus(GISA) strains compared to their susceptible parents. Collectively, our results point to a role forprsAas a facultative facilitator of protein secretion or extracellular folding and provide a framework for understanding whyprsAis a key element of the VraRS-mediated cell wall stress response.

Download Full-text

Global Regulatory Impact of ClpP Protease of Staphylococcus aureus on Regulons Involved in Virulence, Oxidative Stress Response, Autolysis, and DNA Repair

Journal of Bacteriology ◽

10.1128/jb.00074-06 ◽

2006 ◽

Vol 188 (16) ◽

pp. 5783-5796 ◽

Cited By ~ 128

Author(s):

Antje Michel ◽

Franziska Agerer ◽

Christof R. Hauck ◽

Mathias Herrmann ◽

Joachim Ullrich ◽

...

Keyword(s):

Oxidative Stress ◽

Staphylococcus Aureus ◽

Dna Repair ◽

Stress Response ◽

Oxidative Stress Response ◽

Transcriptional Analysis ◽

Expression Of Genes ◽

Wide Range ◽

Genes Encoding ◽

Regulatory Impact

ABSTRACT Staphylococcus aureus is an important pathogen, causing a wide range of infections including sepsis, wound infections, pneumonia, and catheter-related infections. In several pathogens ClpP proteases were identified by in vivo expression technologies to be important for virulence. Clp proteolytic complexes are responsible for adaptation to multiple stresses by degrading accumulated and misfolded proteins. In this report clpP, encoding the proteolytic subunit of the ATP-dependent Clp protease, was deleted, and gene expression of ΔclpP was determined by global transcriptional analysis using DNA-microarray technology. The transcriptional profile reveals a strong regulatory impact of ClpP on the expression of genes encoding proteins that are involved in the pathogenicity of S. aureus and adaptation of the pathogen to several stresses. Expression of the agr system and agr-dependent extracellular virulence factors was diminished. Moreover, the loss of clpP leads to a complete transcriptional derepression of genes of the CtsR- and HrcA-controlled heat shock regulon and a partial derepression of genes involved in oxidative stress response, metal homeostasis, and SOS DNA repair controlled by PerR, Fur, MntR, and LexA. The levels of transcription of genes encoding proteins involved in adaptation to anaerobic conditions potentially regulated by an Fnr-like regulator were decreased. Furthermore, the expression of genes whose products are involved in autolysis was deregulated, leading to enhanced autolysis in the mutant. Our results indicate a strong impact of ClpP proteolytic activity on virulence, stress response, and physiology in S. aureus.

Download Full-text

CpxR/CpxA ControlsscsABCDTranscription To Counteract Copper and Oxidative Stress inSalmonella entericaSerovar Typhimurium

Journal of Bacteriology ◽

10.1128/jb.00126-18 ◽

2018 ◽

Vol 200 (16) ◽

Cited By ~ 10

Author(s):

Carolina López ◽

Susana K. Checa ◽

Fernando C. Soncini

Keyword(s):

Oxidative Stress ◽

Stress Responses ◽

Disulfide Bonds ◽

Redox Balance ◽

Copper Resistance ◽

Gene Arrangement ◽

Copper Stress ◽

Content Type ◽

Disulfide Oxidoreductase ◽

Conserved Gene

ABSTRACTPeriplasmic thiol/disulfide oxidoreductases participate in the formation and isomerization of disulfide bonds and contribute to the virulence of pathogenic microorganisms. Among the systems encoded in theSalmonellagenome, the system encoded by thescsABCDlocus was shown to be required to cope with Cu and H2O2stress. Here we report that this locus forms an operon whose transcription is driven by a promoter upstream ofscsAand depends on CpxR/CpxA and on Cu. Furthermore, genes homologous toscsB,scsC, andscsDare always detected immediately downstream ofscsAand in the same genetic arrangement in allscsA-harboring enterobacterial species. Also, a CpxR-binding site is detected upstream ofscsAin most of those species, providing evidence of evolutionarily conserved function and regulation. Each individualscsgene shows a different role in copper and/or H2O2resistance, indicating hierarchical contributions of these factors in the defense against these intoxicants. A protective effect of Cu preincubation against H2O2toxicity and the increased Cu-mediated activation ofcpxPin the ΔscsABCDmutant suggest that the CpxR/CpxA-controlled transcription of the ScsABCD system contributes to prevent Cu toxicity and to restore the redox balance at theSalmonellaenvelope.IMPORTANCECopper intoxication triggers both specific and nonspecific responses inSalmonella. Thescslocus, which codes for periplasmic thiol/disulfide-oxidoreductase/isomerase-like proteins, has been the focus of attention because it is necessary for copper resistance, oxidative stress responses, and virulence and because it is not present in nonpathogenicEscherichia coli. Still, the conditions under which thescslocus is expressed and the roles of its individual components remain unknown. In this report, we examine the contribution of each Scs factor to survival under H2O2and copper stress. We establish that thescsgenes form a copper-activated operon controlled by the CpxR/CpxA signal transduction system, and we provide evidence of its conserved gene arrangement and regulation in other bacterial pathogens.

Download Full-text

Lack of DNA helicase Pif1 disrupts zinc and iron homoeostasis in yeast

Biochemical Journal ◽

10.1042/bj20101032 ◽

2010 ◽

Vol 432 (3) ◽

pp. 595-608 ◽

Cited By ~ 4

Author(s):

María Guirola ◽

Lina Barreto ◽

Ayelen Pagani ◽

Miriam Romagosa ◽

Antonio Casamayor ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Responses ◽

Nuclear Dna ◽

Transcriptional Profiling ◽

Growth Conditions ◽

Protective Role ◽

Dna Helicase ◽

Dna Integrity ◽

Zinc Tolerance ◽

Genes Encoding

The Saccharomyces cerevisiae gene PIF1 encodes a conserved eukaryotic DNA helicase required for both mitochondrial and nuclear DNA integrity. Our previous work revealed that a pif1Δ strain is tolerant to zinc overload. In the present study we demonstrate that this effect is independent of the Pif1 helicase activity and is only observed when the protein is absent from the mitochondria. pif1Δ cells accumulate abnormal amounts of mitochondrial zinc and iron. Transcriptional profiling reveals that pif1Δ cells under standard growth conditions overexpress aconitase-related genes. When exposed to zinc, pif1Δ cells show lower induction of genes encoding iron (siderophores) transporters and higher expression of genes related to oxidative stress responses than wild-type cells. Coincidently, pif1Δ mutants are less prone to zinc-induced oxidative stress and display a higher reduced/oxidized glutathione ratio. Strikingly, although pif1Δ cells contain normal amounts of the Aco1 (yeast aconitase) protein, they completely lack aconitase activity. Loss of Aco1 activity is also observed when the cell expresses a non-mitochondrially targeted form of Pif1. We postulate that lack of Pif1 forces aconitase to play its DNA protective role as a nucleoid protein and that this triggers a domino effect on iron homoeostasis resulting in increased zinc tolerance.

Download Full-text

Spx Is a Global Effector Impacting Stress Tolerance and Biofilm Formation in Staphylococcus aureus

Journal of Bacteriology ◽

10.1128/jb.00194-06 ◽

2006 ◽

Vol 188 (13) ◽

pp. 4861-4870 ◽

Cited By ~ 104

Author(s):

Sünje Johanna Pamp ◽

Dorte Frees ◽

Susanne Engelmann ◽

Michael Hecker ◽

Hanne Ingmer

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Thioredoxin Reductase ◽

Growth Conditions ◽

Redox Status ◽

Global Regulator ◽

Two Dimensional Gel Electrophoresis ◽

Growth Defects ◽

Stress Protection ◽

Wide Range

ABSTRACT In Bacillus subtilis, Spx was recently characterized as a novel type of global regulator whose activity is regulated by the redox status of the cells. In the present study, we demonstrate that inactivation of Spx in the important pathogen Staphylococcus aureus renders the cells hypersensitive to a wide range of stress conditions including high and low temperature, high osmolarity, and hydrogen peroxide. Moreover, growth was restricted under nonstress conditions. Two-dimensional gel electrophoresis revealed that the proteome of the spx mutant differs substantially from the proteome of wild-type cells, supporting the finding that Spx is also a global regulator in S. aureus. More specifically, we demonstrated that Spx is required for transcription of trxB, encoding thioredoxin reductase, under all growth conditions examined. As trxB is essential in S. aureus, we speculate that the severely reduced trxB transcription could account for some of the growth defects of the spx mutant. Inactivation of spx also enhanced biofilm formation. S. aureus biofilm formation is associated with the production of the polysaccharide intercellular adhesin encoded by the ica operon. Interestingly, our data indicate that the augmented capacity of the spx mutant to form biofilms is due to Spx modulating the expression of icaR, encoding a repressor of the structural ica genes (icaABCD). In summary, we conclude that Spx fulfills an important role for growth, general stress protection, and biofilm formation in S. aureus.

Download Full-text