Effect of extracellular polysaccharide substances on Staphylococcus epidermidis biofilm infections in the invertebrate host model Caenorhabditis elegans

2016 ◽  
Author(s):  
Birthe Kjellerup
Keyword(s):  
Caenorhabditis Elegans ◽  
Staphylococcus Epidermidis ◽  
Extracellular Polysaccharide ◽  
Invertebrate Host ◽  
Extracellular Polysaccharide Substances

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.

scholarly journals Effects of Allicin on the Formation of Pseudomonas aeruginosa Biofilm and the Production of Quorum-Sensing Controlled Virulence Factors

2013 ◽  
Vol 62 (3) ◽  
pp. 243-251 ◽  
Author(s):  
LIN LIHUA ◽  
WANG JIANHUI ◽  
YU JIALIN ◽  
LI YAYIN ◽  
LIU GUANXIN
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Bacterial Pathogen ◽  
Organosulfur Compound ◽  
Extracellular Polysaccharide ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Extracellular Polysaccharide Substances ◽  
Multiple Antibiotics

The Gram-negative Pseudomonas aeruginosa bacterial pathogen is reputed for its resistance to multiple antibiotics, and this property is strongly associated with the development of biofilms. Bacterial biofilms form by aggregation of microorganisms on a solid surface and secretion of an extracellular polysaccharide substances that acts as a physical protection barrier for the encased bacteria. In addition, the P aeruginosa quorum-sensing system contributes to antibiotic resistance by regulating the expression of several virulence factors, including exotoxin A, elastase, pyoverdin and rhamnolipid. The organosulfur compound allicin, derived from garlic, has been shown to inhibit both surface-adherence of bacteria and production of virulence factors. In this study, the effects of allicin on P aeruginosa biofilm formation and the production of quorum-sensing controlled virulence factors were investigated. The results demonstrated that allicin could inhibit early bacterial adhesion, reduce EPS secretion, and down-regulate virulence factors' production. Collectively, these findings suggest the potential of allicin as a therapeutic agent for controlling P aeruginosa biofilm.

scholarly journals Selective retention in saline ice of extracellular polysaccharides produced by the cold-adapted marine bacteriumColwellia psychrerythraeastrain 34H

2011 ◽  
Vol 52 (57) ◽  
pp. 111-117 ◽  
Author(s):  
Marcela Ewert ◽  
Jody W. Deming
Keyword(s):  
Sea Water ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Cold Finger ◽  
Cold Adapted ◽  
Potential Habitat ◽  
Colwellia Psychrerythraea ◽  
Heat Treated ◽  
Selective Retention ◽  
Extracellular Polysaccharide Substances

AbstractThe retention of salts in laboratory-grown ice was compared to the retention of extracellular polysaccharide substances (EPS) produced by the cold-adapted marine gammaproteobacterium,Colwellia psychrerythraeastrain 34H. Saline ice was formed, by means of a cold-finger apparatus, from artificial sea-water solutions containing either native dissolved EPS from strain 34H, the same EPS but heat-treated, or dissolved EPS from the uninoculated growth medium. Results indicated that only the native (unheated) EPS of strain 34H was retained preferentially in the ice. Temperature and volumetric measurements of the ice further suggested a link between the heat-labile fraction of this EPS of marine bacterial origin and potential habitat alteration. Bacterial EPS may join algal EPS in our understanding of how extracellular polymers help to establish and sustain the microbial community that inhabits sea ice.

scholarly journals Characterization of the growth dynamics and biofilm formation of Staphylococcus epidermidis strains isolated from contaminated platelet units

2014 ◽  
Vol 63 (6) ◽  
pp. 884-891 ◽  
Author(s):  
Hamza Ali ◽  
Valerie S. Greco-Stewart ◽  
Michael R. Jacobs ◽  
Roslyn A. Yomtovian ◽  
Ineke G. H. Rood ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Growth Dynamics ◽  
Extracellular Polysaccharide ◽  
Lag Phase ◽  
Infectious Risk ◽  
Slow Growing ◽  
Growth Experiments ◽  
Slow Grower

Bacterial contamination of platelet concentrates (PCs) poses the highest transfusion-associated infectious risk, with Staphylococcus epidermidis being a predominant contaminant. Herein, the growth dynamics of 20 S. epidermidis strains in PCs and regular media were characterized. Strains were categorized as fast (short lag phase) or slow (long lag phase) growers in PCs. All strains were evaluated for the presence of the biofilm-associated icaAD genes by PCR, their capability to produce extracellular polysaccharide (slime) on Congo red agar plates and their ability to form surface-attached aggregates (biofilms) in glucose-supplemented trypticase soy broth (TSBg) using a crystal violet staining assay. A subset of four strains (two slow growers and two fast growers) was further examined for the ability for biofilm formation in PCs. Two of these strains carried the icAD genes, formed slime and produced biofilms in TSBg and PCs, while the other two strains, which did not carry icaAD, did not produce slime or form biofilms in TSBg. Although the two ica-negative slime-negative strains did not form biofilms in media, they displayed a biofilm-positive phenotype in PCs. Although all four strains formed biofilms in PCs, the two slow growers formed significantly more biofilms than the fast growers. Furthermore, growth experiments of the two ica-positive strains in plasma-conditioned platelet bags containing TSBg revealed that a slow grower isolate was more likely to escape culture-based screening than a fast grower strain. Therefore, this study provides novel evidence that links S. epidermidis biofilm formation with slow growth in PCs and suggests that slow-growing biofilm-positive S. epidermidis would be more likely to be missed with automate culture.

scholarly journals AraC-Type Regulator Rbf Controls the Staphylococcus epidermidis Biofilm Phenotype by Negatively Regulating theicaADBCRepressor SarR

2016 ◽  
Vol 198 (21) ◽  
pp. 2914-2924 ◽  
Author(s):  
Sarah E. Rowe ◽  
Christopher Campbell ◽  
Colm Lowry ◽  
Sinead T. O'Donnell ◽  
Michael E. Olson ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Brain Heart Infusion ◽  
Transcriptional Regulator ◽  
Extracellular Polysaccharide ◽  
Opportunistic Pathogen ◽  
Fine Tuning ◽  
Rt Pcr ◽  
Mobility Shift ◽  
Content Type ◽  
Negative Effect

ABSTRACTRegulation oficaADBC-encoded polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosasmine (PNAG) production in staphylococci plays an important role in biofilm-associated medical-device-related infections. Here, we report that the AraC-type transcriptional regulator Rbf activatesicaADBCoperon transcription and PIA production inStaphylococcus epidermidis. Purified recombinant Rbf did not bind to theicaoperon promoter region in electrophoretic mobility shift assays (EMSAs), indicating that Rbf regulatesicatranscription indirectly. To identify the putative transcription factor(s) involved in Rbf-mediatedicaADBCregulation, the ability of recombinant Rbf to interact with the promoter sequences of knownicaADBCregulators was investigated. Recombinant Rbf bound to thesarRpromoter and not thesarX,sarA,sarZ,spx, andsrrApromoters. Reverse transcription (RT)-PCR demonstrated that Rbf acts as a repressor ofsarRtranscription. PIA expression and biofilm production were restored to wild-type levels in anrbf sarRdouble mutant grown in brain heart infusion (BHI) medium supplemented with NaCl, which is known to activate theicalocus, but not in BHI medium alone. RT-PCR further demonstrated that although Rbf does not bind thesarXpromoter, it nevertheless exerted a negative effect onsarXexpression. Apparently, direct downregulation of the SarR repressor by Rbf has a dominant effect over indirect repression of the SarX activator by Rbf in the control ofS. epidermidisPIA production and biofilm formation.IMPORTANCEThe importance ofStaphylococcus epidermidisas an opportunistic pathogen in hospital patients with implanted medical devices derives largely from its capacity to form biofilm. Expression of theicaADBC-encoded extracellular polysaccharide is the predominant biofilm mechanism inS. epidermidisclinical isolates and is tightly regulated. Here, we report that the transcriptional regulator Rbf promotesicaADBCexpression by negatively regulating expression ofsarR, which encodes anicaoperon repressor. Furthermore, Rbf indirectly represses theicaoperon activator, SarX. The data reveal complicated interplay between Rbf and two Sar family proteins in fine-tuning regulation of the biofilm phenotype and indicate that in the hierarchy of biofilm regulators, IcaR is dominant over the Rbf-SarR-SarX axis.

The role of extracellular polysaccharide substance produced by Staphylococcus epidermidis in miliaria

1995 ◽  
Vol 33 (5) ◽  
pp. 729-733 ◽  
Author(s):  
Christen M Mowad ◽  
Kenneth J McGinley ◽  
Arlene Foglia ◽  
James J Leyden
Keyword(s):  
Staphylococcus Epidermidis ◽  
Extracellular Polysaccharide

Production of cryoprotectant extracellular polysaccharide substances (EPS) by the marine psychrophilic bacteriumColwellia psychrerythraeastrain 34H under extreme conditionsThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology.

2009 ◽  
Vol 55 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Joseph G. Marx ◽  
Shelly D. Carpenter ◽  
Jody W. Deming
Keyword(s):  
Deep Sea ◽  
Extreme Environments ◽  
Extracellular Polysaccharide ◽  
Special Issue ◽  
Deep Freezing ◽  
Colwellia Psychrerythraea ◽  
Free Growth ◽  
Effects Of Temperature ◽  
Extracellular Polysaccharide Substances ◽  
Selection Of

Extracellular polysaccharide substances (EPS) play critical roles in microbial ecology, including the colonization of extreme environments in the ocean, from sea ice to the deep sea. After first developing a sugar-free growth medium, we examined the relative effects of temperature, pressure, and salinity on EPS production (on a per cell basis) by the obligately marine and psychrophilic γ-proteobacterium, Colwellia psychrerythraea strain 34H. Over growth-permissive temperatures of ~10 to –4 °C, EPS production did not change, but from –8 to –14 °C when samples froze, EPS production rose dramatically. Similarly, at growth-permissive hydrostatic pressures of 1–200 atm (1 atm = 101.325 kPa) (at –1 and 8 °C), EPS production was unchanged, but at higher pressures of 400 and 600 atm EPS production rose markedly. In salinity tests at 10‰–100‰ (and –1 and 5 °C), EPS production increased at the freshest salinity tested. Extreme environmental conditions thus appear to stimulate EPS production by this strain. Furthermore, strain 34H recovered best from deep-freezing to –80 °C (not found for Earthly environments) if first supplemented with a preparation of its own EPS, rather than other cryoprotectants like glycerol, suggesting EPS production as both a survival strategy and source of compounds with potentially novel properties for biotechnological and other applications.

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