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

2006 ◽  
Vol 188 (13) ◽  
pp. 4861-4870 ◽  
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.

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

2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
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.

Nanostructured Selenium for Preventing Biofilm Formation on Medical Devices

2012 ◽  
Vol 1415 ◽  
Author(s):  
Qi Wang ◽  
Thomas J. Webster
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Device ◽  
Medical Devices ◽  
Biofilm Formation ◽  
In Vitro Study ◽  
Common Cause ◽  
Persistent Infections ◽  
Wide Range ◽  
Novel Material

ABSTRACTBiofilms are a common cause of persistent infections on medical devices as they are easy to form and hard to treat. Selenium and its compounds are considered to be a novel material for a wide range of applications including anticancer applications and antibacterial applications. The objective of this study was to coat selenium nanoparticles on the surface of polycarbonate medical devices and examine their effectiveness at preventing biofilm formation. The results of this in vitro study showed that the selenium coating significantly inhibited Staphylococcus aureus growth on the surface of polycarbonate after 24 hours. Thus, this study suggests that coating polymers with nanostructured selenium is a fast and effective way to reduce bacteria functions leading to medical device infections.

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

2009 ◽  
Vol 76 (1) ◽  
pp. 150-160 ◽  
Author(s):  
Jonathan Baker ◽  
Sutthirat Sitthisak ◽  
Mrittika Sengupta ◽  
Miranda Johnson ◽  
R. K. Jayaswal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Transcriptional Profiling ◽  
Resistance Mechanism ◽  
Growth Conditions ◽  
Copper Resistance ◽  
Transcriptional Analysis ◽  
Copper Stress ◽  
High Copper

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.

scholarly journals A Novel Staphylococcus aureus Biofilm Phenotype Mediated by the Fibronectin-Binding Proteins, FnBPA and FnBPB

2008 ◽  
Vol 190 (11) ◽  
pp. 3835-3850 ◽  
Author(s):  
Eoghan O'Neill ◽  
Clarissa Pozzi ◽  
Patrick Houston ◽  
Hilary Humphreys ◽  
D. Ashley Robinson ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Binding Proteins ◽  
Clinical Problem ◽  
Growth Conditions ◽  
Surface Proteins ◽  
Fibrinogen Binding ◽  
Fibronectin Binding ◽  
Mrsa Strains ◽  
Biofilm Development

ABSTRACT Device-associated infections involving biofilm remain a persistent clinical problem. We recently reported that four methicillin-resistant Staphylococcus aureus (MRSA) strains formed biofilm independently of the icaADBC-encoded exopolysaccharide. Here, we report that MRSA biofilm development was promoted under mildly acidic growth conditions triggered by the addition of glucose to the growth medium. Loss of sortase, which anchors LPXTG-containing proteins to peptidoglycan, reduced the MRSA biofilm phenotype. Furthermore introduction of mutations in fnbA and fnbB, which encode the LPXTG-anchored multifunctional fibrinogen and fibronectin-binding proteins, FnBPA and FnBPB, reduced biofilm formation by several MRSA strains. However, these mutations had no effect on biofilm formation by methicillin-sensitive S. aureus strains. FnBP-promoted biofilm occurred at the level of intercellular accumulation and not primary attachment. Mutation of fnbA or fnbB alone did not substantially affect biofilm, and expression of either gene alone from a complementing plasmid in fnbA fnbB mutants restored biofilm formation. FnBP-promoted biofilm was dependent on the integrity of SarA but not through effects on fnbA or fnbB transcription. Using plasmid constructs lacking regions of FnBPA to complement an fnbAB mutant revealed that the A domain alone and not the domain required for fibronectin binding could promote biofilm. Additionally, an A-domain N304A substitution that abolished fibrinogen binding did not affect biofilm. These data identify a novel S. aureus biofilm phenotype promoted by FnBPA and FnBPB which is apparently independent of the known ligand-binding activities of these multifunctional surface proteins.

Removal of Listeria monocytogenes Biofilms with Bacteriophage P100†

2010 ◽  
Vol 73 (8) ◽  
pp. 1519-1524 ◽  
Author(s):  
KAMLESH A. SONI ◽  
RAMAKRISHNA NANNAPANENI
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Foodborne Pathogen ◽  
Growth Conditions ◽  
Cell Populations ◽  
Wide Range ◽  
Serotype 1 ◽  
Stainless Steel Coupon ◽  
Steel Coupon

Listeria monocytogenes is an important foodborne pathogen with a persistent ability to form biofilm matrices in the food processing environments. In this study, we have determined the ability of bacteriophage P100 to reduce L. monocytogenes cell populations under biofilm conditions by using 21 L. monocytogenes strains representing 13 different serotypes. There were considerable differences in the ability of various strains of L. monocytogenes to form biofilms, with strains of serotype 1/2a showing maximum biofilm formation. Irrespective of the serotype, growth conditions, or biofilm levels, the phage P100 treatment significantly reduced L. monocytogenes cell populations under biofilm conditions. On the stainless steel coupon surface, there was a 3.5- to 5.4-log/cm2 reduction in L. monocytogenes cells by phage treatment. These findings illustrate that phage P100 is active against a wide range of L. monocytogenes strains in biofilm conditions.

scholarly journals Global Gene Expression in Staphylococcus aureus Biofilms

2004 ◽  
Vol 186 (14) ◽  
pp. 4665-4684 ◽  
Author(s):  
Karen E. Beenken ◽  
Paul M. Dunman ◽  
Fionnuala McAleese ◽  
Daphne Macapagal ◽  
Ellen Murphy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Adaptive Response ◽  
Biofilm Formation ◽  
Global Gene Expression ◽  
Growth Conditions ◽  
Anaerobic Growth ◽  
Over Expression ◽  
Custom Made

ABSTRACT We previously demonstrated that mutation of the staphylococcal accessory regulator (sarA) in a clinical isolate of Staphylococcus aureus (UAMS-1) results in an impaired capacity to form a biofilm in vitro (K. E. Beenken, J. S. Blevins, and M. S. Smeltzer, Infect. Immun. 71:4206-4211, 2003). In this report, we used a murine model of catheter-based biofilm formation to demonstrate that a UAMS-1 sarA mutant also has a reduced capacity to form a biofilm in vivo. Surprisingly, mutation of the UAMS-1 ica locus had little impact on biofilm formation in vitro or in vivo. In an effort to identify additional loci that might be relevant to biofilm formation and/or the adaptive response required for persistence of S. aureus within a biofilm, we isolated total cellular RNA from UAMS-1 harvested from a biofilm grown in a flow cell and compared the transcriptional profile of this RNA to RNA isolated from both exponential- and stationary-phase planktonic cultures. Comparisons were done using a custom-made Affymetrix GeneChip representing the genomic complement of six strains of S. aureus (COL, N315, Mu50, NCTC 8325, EMRSA-16 [strain 252], and MSSA-476). The results confirm that the sessile lifestyle associated with persistence within a biofilm is distinct by comparison to the lifestyles of both the exponential and postexponential phases of planktonic culture. Indeed, we identified 48 genes in which expression was induced at least twofold in biofilms over expression under both planktonic conditions. Similarly, we identified 84 genes in which expression was repressed by a factor of at least 2 compared to expression under both planktonic conditions. A primary theme that emerged from the analysis of these genes is that persistence within a biofilm requires an adaptive response that limits the deleterious effects of the reduced pH associated with anaerobic growth conditions.

scholarly journals Molecular Cloning and Analysis of a Putative Siderophore ABC Transporter from Staphylococcus aureus

2000 ◽  
Vol 68 (11) ◽  
pp. 6281-6288 ◽  
Author(s):  
Julie A. Morrissey ◽  
Alan Cockayne ◽  
Philip J. Hill ◽  
Paul Williams
Keyword(s):  
Staphylococcus Aureus ◽  
Abc Transporter ◽  
Growth Conditions ◽  
Expression Library ◽  
Phase Partitioning ◽  
Wide Range ◽  
Monospecific Antisera ◽  
Triton X

ABSTRACT From a mass-excised Staphylococcus aureus λZapII expression library, we cloned an operon encoding a novel ABC transporter with significant homology to bacterial siderophore transporter systems. The operon encodes four genes designatedsstA, -B, -C, and -Dencoding two putative cytoplasmic membrane proteins (sstAand sstB), an ATPase (sstC), and a membrane-bound 38-kDa lipoprotein (sstD). Thesst operon is preceded by two putative Fur boxes, which indicated that expression of the sst operon was likely to be iron dependent. SstD was overexpressed inEscherichia coli, purified by Triton X-114 phase partitioning, and used to generate monospecific antisera in rats. Immunoblotting studies located SstD in the membrane fraction ofS. aureus and showed that expression of the lipoprotein was reduced under iron-rich growth conditions. Triton X-114 partitioning studies on isolated membranes provided additional biochemical evidence that SstD in S. aureus is a lipoprotein. Immunoreactive polypeptides of approximately 38 kDa were detected in a wide range of staphylococcal species, but no antigenic homolog was detected inBacillus subtilis. Expression of SstD in vivo was confirmed by immunoblotting studies with S. aureus recovered from a rat intraperitoneal chamber implant model. To further define the contribution of SstD in promoting growth of S. aureus in vitro and in vivo, we used antisense RNA technology to modulate expression of SstD. Expression of antisense sstD RNA inS. aureus resulted in a decrease in SstD expression under both iron-rich and iron-restricted growth conditions. However, this reduction in SstD levels did not affect the growth of S. aureus in vitro in an iron-limited growth medium or when grown in an intraperitoneal rat chamber implant model in vivo.

scholarly journals Graphene Decorated Zinc Oxide and Curcumin to Disinfect the Methicillin-Resistant Staphylococcus aureus

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 1004
Author(s):  
Mohammad Oves ◽  
Mohd. Ahmar Rauf ◽  
Mohammad Omaish Ansari ◽  
Aftab Aslam Parwaz Khan ◽  
Huda A Qari ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Zinc Oxide ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Wall Structure ◽  
Resistant Bacteria ◽  
Mice Model ◽  
Zno Nps ◽  
Methicillin Resistant ◽  
Wide Range

Sometimes, life-threatening infections are initiated by the biofilm formation facilitated at the infection site by the drug-resistant bacteria Staphylococcus aureus. The aggregation of the same type of bacteria leads to biofilm formation on the delicate tissue, dental plaque, and skin. In the present investigation, a Graphene (Gr)-based nano-formulation containing Curcumin (C.C.M.) and Zinc oxide nanoparticles (ZnO-NPs) showed a wide range of anti-microbial activity against Methicillin-resistant Staphylococcus aureus (MRSA) biofilm and demonstrated the anti-microbial mechanism of action. The anti-microbial effect of GrZnO nanocomposites, i.e., GrZnO-NCs, suggests that the integrated graphene-based nanocomposites effectively suppressed both sensitive as well as MRSA ATCC 43300 and BAA-1708 isolates. The S. aureus inhibitory effect of GrZnO-NCs improved >5-fold when combined with C.C.M., and demonstrated a M.I.C. of 31.25 µg/mL contrasting with the GrZnO-NCs or C.C.M. alone having M.I.C. value of 125 µg/mL each. The combination treatment of GrZnO-NCs or C.C.M. inhibited the M.R.S.A. topical dermatitis infection in a mice model with a significant decrease in the CFU count to ~64%. Interestingly, the combination of C.C.M. and GrZnO-NCs damaged the bacterial cell wall structure, resulting in cytoplasm spillage, thereby diminishing their metabolism. Thus, owing to the ease of synthesis and highly efficient anti-microbial properties, the present graphene-based curcumin nano-formulations can cater to a new treatment methodology against M.R.S.A.

scholarly journals Iron-Regulated Biofilm Formation in Staphylococcus aureus Newman Requires ica and the Secreted Protein Emp

2008 ◽  
Vol 76 (4) ◽  
pp. 1756-1765 ◽  
Author(s):  
Miranda Johnson ◽  
Alan Cockayne ◽  
Julie A. Morrissey
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Secreted Proteins ◽  
Iron Regulation ◽  
Secreted Protein ◽  
Virulence Determinants

ABSTRACT Staphylococcus aureus biofilm formation is induced in iron-restricted growth conditions in vitro. In this study, we showed that Emp and Eap play important roles in low-iron-induced biofilm formation of S. aureus Newman. Eap and Emp are secreted proteins which are non-covalently attached to the S. aureus cell surface and have previously been implicated in a number of aspects of S. aureus pathogenesis. We showed here that the transcription of these important virulence factors is induced by growth in low-iron medium, reflective of the in vivo environment. Our results show that iron regulation of Eap and Emp is Fur independent. However, Fur is required for full induction of eap and emp expression in low-iron conditions. In this study, we demonstrated that in addition to Fur, low-iron-induced biofilm formation requires Sae, Agr, and SarA. In iron-restricted growth conditions, Sae and Agr are essential for Emp and Eap expression and hence for biofilm formation, whereas SarA appears to have a less-significant role. We also showed that expression of the ica operon is required for biofilm formation in iron-restricted growth conditions. We demonstrated that in fact, ica is required for the expression of the important multifunctional virulence determinants eap and emp.

Sign in / Sign up

Export Citation Format

Share Document