A Single B-Repeat of Staphylococcus epidermidis Accumulation-Associated Protein Induces Protective Immune Responses in an Experimental Biomaterial-Associated Infection Mouse Model

ABSTRACTNosocomial infections are the fourth leading cause of morbidity and mortality in the United States, resulting in 2 million infections and ∼100,000 deaths each year. More than 60% of these infections are associated with some type of biomedical device.Staphylococcus epidermidisis a commensal bacterium of the human skin and is the most common nosocomial pathogen infecting implanted medical devices, especially those in the cardiovasculature.S. epidermidisantibiotic resistance and biofilm formation on inert surfaces make these infections hard to treat. Accumulation-associated protein (Aap), a cell wall-anchored protein ofS. epidermidis, is considered one of the most important proteins involved in the formation ofS. epidermidisbiofilm. A small recombinant protein vaccine comprising a single B-repeat domain (Brpt1.0) ofS. epidermidisRP62A Aap was developed, and the vaccine's efficacy was evaluatedin vitrowith a biofilm inhibition assay andin vivoin a murine model of biomaterial-associated infection. A high IgG antibody response againstS. epidermidisRP62A was detected in the sera of the mice after two subcutaneous immunizations with Brpt1.0 coadministered with Freund's adjuvant. Sera from Brpt1.0-immunized mice inhibitedin vitroS. epidermidisRP62A biofilm formation in a dose-dependent pattern. After receiving two immunizations, each mouse was surgically implanted with a porous scaffold disk containing 5 × 106CFU ofS. epidermidisRP62A. Weight changes, inflammatory markers, and histological assay results after challenge withS. epidermidisindicated that the mice immunized with Brpt1.0 exhibited significantly higher resistance toS. epidermidisRP62A implant infection than the control mice. Day 8 postchallenge, there was a significantly lower number of bacteria in scaffold sections and surrounding tissues and a lower residual inflammatory response to the infected scaffold disks for the Brpt1.0-immunized mice than for of the ovalbumin (Ova)-immunized mice.

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Accumulation-Associated Protein Enhances Staphylococcus epidermidis Biofilm Formation under Dynamic Conditions and Is Required for Infection in a Rat Catheter Model

Infection and Immunity ◽

10.1128/iai.02177-14 ◽

2014 ◽

Vol 83 (1) ◽

pp. 214-226 ◽

Cited By ~ 63

Author(s):

Carolyn R. Schaeffer ◽

Keith M. Woods ◽

G. Matt Longo ◽

Megan R. Kiedrowski ◽

Alexandra E. Paharik ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Host Cells ◽

Content Type ◽

Microtiter Plates ◽

Allelic Replacement ◽

Abiotic Surfaces ◽

Cell Accumulation ◽

Accumulation Associated Protein

Biofilm formation is the primary virulence factor ofStaphylococcus epidermidis.S. epidermidisbiofilms preferentially form on abiotic surfaces and may contain multiple matrix components, including proteins such as accumulation-associated protein (Aap). Following proteolytic cleavage of the A domain, which has been shown to enhance binding to host cells, B domain homotypic interactions support cell accumulation and biofilm formation. To further define the contribution of Aap to biofilm formation and infection, we constructed anaapallelic replacement mutant and anicaADBC aapdouble mutant. When subjected to fluid shear, strains deficient in Aap production produced significantly less biofilm than Aap-positive strains. To examine thein vivorelevance of our findings, we modified our previously described rat jugular catheter model and validated the importance of immunosuppression and the presence of a foreign body to the establishment of infection. The use of our allelic replacement mutants in the model revealed a significant decrease in bacterial recovery from the catheter and the blood in the absence of Aap, regardless of the production of polysaccharide intercellular adhesin (PIA), a well-characterized, robust matrix molecule. Complementation of theaapmutant with full-length Aap (containing the A domain), but not the B domain alone, increased initial attachment to microtiter plates, as did intransexpression of the A domain in adhesion-deficientStaphylococcus carnosus. These results demonstrate Aap contributes toS. epidermidisinfection, which may in part be due to A domain-mediated attachment to abiotic surfaces.

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Oral Administration of the Broad-Spectrum Antibiofilm Compound Toremifene Inhibits Candida albicans and Staphylococcus aureus Biofilm FormationIn Vivo

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03869-14 ◽

2014 ◽

Vol 58 (12) ◽

pp. 7606-7610 ◽

Cited By ~ 16

Author(s):

Kaat De Cremer ◽

Nicolas Delattin ◽

Katrijn De Brucker ◽

Annelies Peeters ◽

Soña Kucharíková ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Candida Albicans ◽

Broad Spectrum ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Candida Krusei ◽

Content Type ◽

And Staphylococcus Aureus

ABSTRACTWe here report on thein vitroactivity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, includingCandida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Pseudomonas aeruginosa,Staphylococcus aureus, andStaphylococcus epidermidis. We validated thein vivoefficacy of orally administered toremifene againstC. albicans and S. aureusbiofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound.

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Study of the impact of cultivation conditions and peg surface modification on the in vitro biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis in a system analogous to the Calgary biofilm device

Journal of Medical Microbiology ◽

10.1099/jmm.0.001371 ◽

2021 ◽

Vol 70 (5) ◽

Author(s):

Adéla Diepoltová ◽

Klára Konečná ◽

Ondřej Janďourek ◽

Petr Nachtigal

Keyword(s):

Staphylococcus Aureus ◽

Surface Modification ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Type Species ◽

Cultivation Conditions ◽

Content Type ◽

Link Type ◽

The Impact

Introduction. Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) are the most common pathogens from the genus Staphylococcus causing biofilm-associated infections. Generally, biofilm-associated infections represent a clinical challenge. Bacteria in biofilms are difficult to eradicate due to their resistance and serve as a reservoir for recurring persistent infections. Gap Statement. A variety of protocols for in vitro drug activity testing against staphylococcal biofilms have been introduced. However, there are often fundamental differences. All these differences in methodical approaches can then be reflected in the form of discrepancies between results. Aim. In this study, we aimed to develop optimal conditions for staphylococcal biofilm formation on pegs. The impact of peg surface modification was also studied. Methodology. The impact of tryptic soy broth alone or supplemented with foetal bovine serum (FBS) or human plasma (HP), together with the impact of the inoculum density of bacterial suspensions and the shaking versus the static mode of cultivation, on total biofilm biomass production in SA and SE reference strains was studied. The surface of pegs was modified with FBS, HP, or poly-l-lysine (PLL). The impact on total biofilm biomass was evaluated using the crystal violet staining method and statistical data analysis. Results. Tryptic soy broth supplemented with HP together with the shaking mode led to crucial potentiation of biofilm formation on pegs in SA strains. The SE strain did not produce biofilm biomass under the same conditions on pegs. Preconditioning of peg surfaces with FBS and HP led to a statistically significant increase in biofilm biomass formation in the SE strain. Conclusion. Optimal cultivation conditions for robust staphylococcal biofilm formation in vitro might differ among different bacterial strains and methodical approaches. The shaking mode and supplementation of cultivation medium with HP was beneficial for biofilm formation on pegs for SA (ATCC 29213) and methicillin-resistant SA (ATCC 43300). Peg conditioning with HP and PLL had no impact on biofilm formation in either of these strains. Peg coating with FBS showed an adverse effect on the biofilm formation of these strains. By contrast, there was a statistically significant increase in biofilm biomass production on pegs coated with FBS and HP for SE (ATCC 35983).

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Vaccination with SesC Decreases Staphylococcus epidermidis Biofilm Formation

Infection and Immunity ◽

10.1128/iai.00104-12 ◽

2012 ◽

Vol 80 (10) ◽

pp. 3660-3668 ◽

Cited By ~ 37

Author(s):

Mohammad Shahrooei ◽

Vishal Hira ◽

Laleh Khodaparast ◽

Ladan Khodaparast ◽

Benoit Stijlemans ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Inhibitory Effect ◽

Antigenic Determinants ◽

Infection Model ◽

Content Type ◽

Protein Size ◽

Promising Target

ABSTRACTThe increased use of medical implants has resulted in a concomitant rise in device-related infections. The majority of these infections are caused byStaphylococcus epidermidisbiofilms. Immunoprophylaxis and immunotherapy targetingin vivo-expressed, biofilm-associated, bacterial cell surface-exposed proteins are promising new approaches to prevent and treat biofilm-related infections, respectively. Using anin silicoprocedure, we identified 64 proteins that are predicted to beS.epidermidissurface exposed (Ses), of which 36 were annotated as (conserved) hypothetical. Of these 36 proteins, 5 proteins—3 LPXTG motif-containing proteins (SesL, SesB, and SesC) and 2 of the largest ABC transporters (SesK and SesM)—were selected for evaluation as vaccine candidates. This choice was based on protein size, number of antigenic determinants, or the established role inS. epidermidisbiofilm formation of the protein family to which the candidate protein belongs. Anti-SesC antibodies exhibited the greatest inhibitory effect onS. epidermidisbiofilm formationin vitroand on colonization and infection in a mouse jugular vein catheter infection model that includes biofilms and organ infections. Active vaccination with a recombinant truncated SesC inhibitedS. epidermidisbiofilm formation in a rat model of subcutaneous foreign body infection. Antibodies to SesC were shown to be opsonic by anin vitroopsonophagocytosis assay. We conclude that SesC is a promising target for antibody mediated strategies againstS. epidermidisbiofilm formation.

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Fluid Flow Induces Biofilm Formation in Staphylococcus epidermidis Polysaccharide Intracellular Adhesin-Positive Clinical Isolates

Applied and Environmental Microbiology ◽

10.1128/aem.01139-12 ◽

2012 ◽

Vol 78 (16) ◽

pp. 5890-5896 ◽

Cited By ~ 35

Author(s):

Westbrook M. Weaver ◽

Vladana Milisavljevic ◽

Jeff F. Miller ◽

Dino Di Carlo

Keyword(s):

Fluid Flow ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Hospital Costs ◽

Bloodstream Infections ◽

Clinical Isolates ◽

Content Type ◽

Biofilm Structure

ABSTRACTStaphylococcus epidermidisis a common cause of catheter-related bloodstream infections, resulting in significant morbidity and mortality and increased hospital costs. The ability to form biofilms plays a crucial role in pathogenesis; however, not all clinical isolates form biofilms under normalin vitroconditions. Strains containing theicaoperon can display significant phenotypic variation with respect to polysaccharide intracellular adhesin (PIA)-based biofilm formation, including the induction of biofilms upon environmental stress. Using a parallel microfluidic approach to investigate flow as an environmental signal forS. epidermidisbiofilm formation, we demonstrate that fluid shear alone induces PIA-positive biofilms of certain clinical isolates and influences biofilm structure. These findings suggest an important role of the catheter microenvironment, particularly fluid flow, in the establishment ofS. epidermidisinfections by PIA-dependent biofilm formation.

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In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05061-11 ◽

2011 ◽

Vol 56 (1) ◽

pp. 148-153 ◽

Cited By ~ 15

Author(s):

Marisa H. Miceli ◽

Stella M. Bernardo ◽

T. S. Neil Ku ◽

Carla Walraven ◽

Samuel A. Lee

Keyword(s):

Candida Albicans ◽

Metabolic Activity ◽

Biofilm Formation ◽

High Dose ◽

Dependent Manner ◽

Planktonic Cells ◽

Content Type ◽

Heparin Sodium ◽

The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

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Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

Infection and Immunity ◽

10.1128/iai.05773-11 ◽

2011 ◽

Vol 80 (1) ◽

pp. 3-13 ◽

Cited By ~ 27

Author(s):

Chen Li ◽

Kurniyati ◽

Bo Hu ◽

Jiang Bian ◽

Jianlan Sun ◽

...

Keyword(s):

Porphyromonas Gingivalis ◽

Biofilm Formation ◽

Adult Population ◽

Transcriptional Analysis ◽

Wild Type ◽

Content Type ◽

Multiple Organs ◽

Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

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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.

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Impact of pH on growth of Staphylococcus epidermidis and Staphylococcus aureus in vitro

Journal of Medical Microbiology ◽

10.1099/jmm.0.001421 ◽

2021 ◽

Vol 70 (9) ◽

Author(s):

Vidula Iyer ◽

Janhavi Raut ◽

Anindya Dasgupta

Keyword(s):

Staphylococcus Aureus ◽

Growth Kinetics ◽

Staphylococcus Epidermidis ◽

Type Species ◽

Ph Dependence ◽

Skin Microbiome ◽

Content Type ◽

Link Type ◽

Kinetics Of

The pH of skin is critical for skin health and resilience and plays a key role in controlling the skin microbiome. It has been well reported that under dysbiotic conditions such as atopic dermatitis (AD), eczema, etc. there are significant aberrations of skin pH, along with a higher level of Staphylococcus aureus compared to the commensal Staphylococcus epidermidis on skin. To understand the effect of pH on the relative growth of S. epidermidis and S. aureus , we carried out simple in vitro growth kinetic studies of the individual microbes under varying pH conditions. We demonstrated that the growth kinetics of S. epidermidis is relatively insensitive to pH within the range of 5–7, while S. aureus shows a stronger pH dependence in that range. Gompertz’s model was used to fit the pH dependence of the growth kinetics of the two bacteria and showed that the equilibrium bacterial count of S. aureus was the more sensitive parameter. The switch in growth rate happens at a pH of 6.5–7. Our studies are in line with the general hypothesis that keeping the skin pH within an acidic range is advantageous in terms of keeping the skin microbiome in balance and maintaining healthy skin.

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Novel regulators of the csgD gene encoding the master regulator of biofilm formation in Escherichia coli K-12

Microbiology ◽

10.1099/mic.0.000947 ◽

2020 ◽

Vol 166 (9) ◽

pp. 880-890 ◽

Cited By ~ 1

Author(s):

Hiroshi Ogasawara ◽

Toshiyuki Ishizuka ◽

Shuhei Hotta ◽

Michiko Aoki ◽

Tomohiro Shimada ◽

...

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Cell Aggregation ◽

Master Regulator ◽

Gene Encoding ◽

Content Type ◽

Promoter Probe ◽

K 12 ◽

Specific Environmental Condition

Under stressful conditions, Escherichia coli forms biofilm for survival by sensing a variety of environmental conditions. CsgD, the master regulator of biofilm formation, controls cell aggregation by directly regulating the synthesis of Curli fimbriae. In agreement of its regulatory role, as many as 14 transcription factors (TFs) have so far been identified to participate in regulation of the csgD promoter, each monitoring a specific environmental condition or factor. In order to identify the whole set of TFs involved in this typical multi-factor promoter, we performed in this study ‘promoter-specific transcription-factor’ (PS-TF) screening in vitro using a set of 198 purified TFs (145 TFs with known functions and 53 hitherto uncharacterized TFs). A total of 48 TFs with strong binding to the csgD promoter probe were identified, including 35 known TFs and 13 uncharacterized TFs, referred to as Y-TFs. As an attempt to search for novel regulators, in this study we first analysed a total of seven Y-TFs, including YbiH, YdcI, YhjC, YiaJ, YiaU, YjgJ and YjiR. After analysis of curli fimbriae formation, LacZ-reporter assay, Northern-blot analysis and biofilm formation assay, we identified at least two novel regulators, repressor YiaJ (renamed PlaR) and activator YhjC (renamed RcdB), of the csgD promoter.

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