Biocompatibilidad de osteoblastos e inhibición de adhesión bacteriana a la aleación Ti6Al4V tratada térmica y químicamente

2021 ◽  
Vol 57 (4) ◽  
pp. e208
Author(s):  
Greta Tavarez-Martínez ◽  
Belén Criado ◽  
M. Coronada Fernández-Calderón ◽  
Edgar Onofre-Bustamante ◽  
Ciro Pérez-Giraldo ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis

El objetivo de este trabajo ha sido estudiar si los tratamientos térmicos y de conversión química mejoran la biocompatibilidad de la aleación TiAlV y reducen el crecimiento bacteriano. En primer lugar, se modificó la aleación de TiAlV mediante tratamiento térmico a 650 ºC durante 1 hour. Luego, se llevó a cabo la conversión química en una solución de CeCl3 para generar óxido de cerio. Las superficies modificadas se caracterizaron utilizando AFM y SEM-EDX. La adhesión de osteoblastos y la formación de biopelículas microbianas se midieron in vitro con la línea celular de osteoblastos MC3T3-E1 y Staphylococcus epidermidis ATCC 35983, respectivamente. La viabilidad bacteriana se cuantificó a través del contenido en trifosfato de adenosina (ATP) como medida de la actividad metabólica. La morfología y la proliferación en superficies modificadas se analizaron mediante SEM-EDX. Los resultados revelaron que el TiAlV tratado térmicamente mostró una mayor proliferación osteoblástica asociada con una mayor rugosidad y estructura cristalina del rutilo. Las superficies modificadas no causaron efecto bactericida, pero las superficies de TiAlV con ceria mostraron una disminución en la adhesión bacteriana, es decir, menos proliferación bacteriana y por tanto disminución en la colonización bacteriana.

Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters

1985 ◽  
Vol 43 ◽  
pp. 520-521
Author(s):  
William J. Lamoreaux ◽  
David L. Smalley ◽  
Larry M. Baddour ◽  
Alfred P. Kraus
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Staphylococcus Epidermidis ◽  
Sterile Saline ◽  
Intravascular Devices ◽  
Capd Patient ◽  
Scanning Electron

Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.

Investigating Non-Therapeutic Pharmaceutical Substances for Improving In-Vitro Efficacy of Clindamycin Phosphate Against MRSA and Staphylococcus Epidermidis

2020 ◽  
Vol 18 (2) ◽  
pp. 63-72
Author(s):  
Mohd Aftab Alam ◽  
Fahad I. Al-Jenoobi ◽  
Khaled A. Alzahrani ◽  
Mohammad H. Al-Agamy ◽  
Abdullah M. Al-Mohizea
Keyword(s):  
Fusidic Acid ◽  
Staphylococcus Epidermidis ◽  
Sorbic Acid ◽  
Tween 80 ◽  
Lauryl Sulfate ◽  
Individual Substance ◽  
Dependent Effect ◽  
Pharmaceutical Excipients ◽  
Active Substances

The aim of present study was to investigate the effect of pharmaceutical excipients and other active substances on antimicrobial efficacy of standard antibiotic against resistant and susceptible microorganisms. Pharmaceutical excipients (sodium lauryl sulfate [SLS], Tween-80, citric acid, NaOH, NaCl) and active substances (fusidic acid, sorbic acid) were investigated to check in-vitro efficacy and their effect on the efficacy of standard antibiotic. Clindamycin was selected as standard antibiotic. Clindamycin was found to be ineffective against methicillin-resistant Staphylococcus aureus (MRSA). Fusidic acid and SLS showed concentration dependent effect against MRSA. Other tested substances were also ineffective against MRSA, and also failed to improve the susceptibility of MRSA towards clindamycin. The clindamycin + fusidic acid (0.05 µg, 0.1 µg), and clindamycin + SLS (0.5 mg, 1 mg) showed concentration dependent effect on Staphylococcus epidermidis (S. epidermidis). Clindamycin combinations with fusidic acid or SLS showed better inhibition of S. epidermidis, than individual substance. At lower concentration of clindamycin (2 µg), the sorbic acid (25 µg) improves its effectiveness. SLS (0.5 mg, 1 mg) and clindamycin (4 µg, 10 µg) showed almost equal zone of inhibition against S. epidermidis, respectively. Present findings showed that certain pharmaceutical excipients (e.g. SLS) are effective against resistant and susceptible microbes, and suggested that more excipients should be screened for their antimicrobial potential and their ability to improve the efficacy of standard antibiotics.

scholarly journals The bactericidal effect of vancomycin is not altered by tranexamic acid, adrenalin, dexamethasone, or lidocaine in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christiane Schwerdt ◽  
Eric Röhner ◽  
Sabrina Böhle ◽  
Benjamin Jacob ◽  
Georg Matziolis
Keyword(s):  
Staphylococcus Aureus ◽  
Tranexamic Acid ◽  
Total Joint Arthroplasty ◽  
Staphylococcus Epidermidis ◽  
Joint Infection ◽  
Bactericidal Effect ◽  
Joint Arthroplasty ◽  
Zone Of Inhibition ◽  
Agar Diffusion Test

AbstractOne of the most challenging complications of total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). There is growing evidence of a good anti-infective effect of intrawound vancomycin powder in total joint arthroplasty. At the same time, various different locally applied substances have become popular in total joint arthroplasty. The objective of this study was therefore to investigate a possible inhibition of the bactericidal effect of vancomycin by tranexamic acid, adrenalin, lidocaine, or dexamethasone. The bactericidal effect of vancomycin was quantified using the established method of the agar diffusion test. The plates were incubated with Staphylococcus aureus or Staphylococcus epidermidis and four wells were stamped out. The wells were filled with vancomycin alone, the tested substance alone or a mixture of the two. The fourth well remained empty as a control. The plates were incubated overnight at 37 °C and the zone of inhibition in each field was measured on the next day. All tests were run three times for each pathogen and mean values and standard deviations of the measurements were calculated. Differences between the substances were tested using the t-test at a level of significance of 0.05. The bacterial growth was homogeneous on all plates. The baseline value for the zone of inhibition of vancomycin was on average 6.2 ± 0.4 mm for Staphylococcus aureus and 12 ± 0.3 mm for Staphylococcus epidermidis. In all other substances, no inhibition was detected around the well. The combination of vancomycin and each other substance did not show any different result compared to vancomycin alone. The bactericidal effect of vancomycin on staphylococci is not altered by tranexamic acid, adrenalin, dexamethasone, or lidocaine in vitro.

scholarly journals Synthesis, Characterization and Testing of Antimicrobial Activity of Composites of Unsaturated Polyester Resins with Wood Flour and Silver Nanoparticles

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1122
Author(s):  
Przemysław Pączkowski ◽  
Andrzej Puszka ◽  
Malgorzata Miazga-Karska ◽  
Grażyna Ginalska ◽  
Barbara Gawdzik
Keyword(s):  
Silver Nanoparticles ◽  
Staphylococcus Epidermidis ◽  
Polyester Resin ◽  
Wood Flour ◽  
Unsaturated Polyester ◽  
Thermomechanical Properties ◽  
Resin Composites ◽  
Polyester Resins ◽  
Before And After

This paper presents the properties of the wood-resin composites. For improving their antibacterial character, silver nanoparticles were incorporated into their structures. The properties of the obtained materials were analyzed in vitro for their anti-biofilm potency in contact with aerobic Gram-positive Staphylococcus aureus and Staphylococcus epidermidis; and aerobic Gram-negative Escherichia coli and Pseudomonas aeruginosa. These pathogens are responsible for various infections, including those associated with healthcare. The effect of silver nanoparticles incorporation on mechanical and thermomechanical properties as well as gloss were investigated for the samples of composites before and after accelerating aging tests. The results show that bacteria can colonize in various wrinkles and cracks on the composites with wood flour but also the surface of the cross-linked unsaturated polyester resin. The addition of nanosilver causes the death of bacteria. It also positively influences mechanical and thermomechanical properties as well as gloss of the resin.

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

2014 ◽  
Vol 21 (9) ◽  
pp. 1206-1214 ◽  
Author(s):  
Lin Yan ◽  
Lei Zhang ◽  
Hongyan Ma ◽  
David Chiu ◽  
James D. Bryers
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Porous Scaffold ◽  
The United States ◽  
Protein Vaccine ◽  
Weight Changes ◽  
Biofilm Inhibition ◽  
Content Type ◽  
Accumulation Associated Protein

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.

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 In Vitro Time-Kill of Common Ocular Pathogens with Besifloxacin Alone and in Combination with Benzalkonium Chloride

2021 ◽  
Vol 14 (6) ◽  
pp. 517
Author(s):  
Joseph Blondeau ◽  
Heleen DeCory
Keyword(s):  
Staphylococcus Epidermidis ◽  
Benzalkonium Chloride ◽  
Bacterial Species ◽  
Drug Resistant ◽  
Resistance Development ◽  
Aureus Isolate ◽  
Killing Activity ◽  
Time Kill ◽  
Variable Impact

Background: Besifloxacin ophthalmic suspension 0.6% (w/v%) contains benzalkonium chloride (BAK) as a preservative. We evaluated the in vitro time-kill activity of besifloxacin, alone and in combination with BAK, against common bacteria implicated in ophthalmic infections. Methods: The activity of besifloxacin (100 µg/mL), BAK (10, 15, 20, and 100 µg/mL), and combinations of besifloxacin and BAK were evaluated against isolates of Staphylococcus epidermidis (n = 4), Staphylococcus aureus (n = 3), Haemophilus influenzae (n = 2), and Pseudomonas aeruginosa (n = 2) in time-kill experiments of 180 min duration. With the exception of one S. aureus isolate, all of the staphylococcal isolates were methicillin- and/or ciprofloxacin-resistant; one P. aeruginosa isolate was ciprofloxacin-resistant. The reductions in the viable colony counts (log10 CFU/mL) were plotted against time, and the differences among the time–kill curves were evaluated using an analysis of variance. Areas-under-the-killing-curve (AUKCs) were also computed. Results: Besifloxacin alone demonstrated ≥3-log killing of P. aeruginosa (<5 min) and H. influenzae (<120 min), and approached 3-log kills of S. aureus. BAK alone demonstrated concentration-dependent killing of S. epidermidis, S. aureus and H. influenzae, and at 100 µg/mL produced ≥3-log kills in <5 min against these species. The addition of BAK (10, 15, and 20 µg/mL) to besifloxacin increased the rate of killing compared to besifloxacin alone, with earlier 3-log kills of all species except P. aeruginosa and a variable impact on S. aureus. The greatest reductions in AUKC were observed among H. influenzae (8-fold) and S. epidermidis (≥5-fold). Similar results were found when the isolates were evaluated individually by their resistance phenotype. Conclusions: In addition to confirming the activity of 100 µg/mL BAK as a preservative in the bottle, these data suggest that BAK may help besifloxacin to achieve faster time-kills on-eye in the immediate timeframe post-instillation before extensive dilution against bacterial species implicated in ophthalmic infections, including drug-resistant S. epidermidis. Greater killing activity may help prevent resistance development and/or help treat resistant organisms.

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

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.

Impaired Cytokine Responses to Live Staphylococcus epidermidis in Preterm Infants Precede Gram-positive, Late-onset Sepsis

2020 ◽  
Author(s):  
Tobias Strunk ◽  
Julie Hibbert ◽  
Dorota Doherty ◽  
Elizabeth Nathan ◽  
Karen Simmer ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Staphylococcus Epidermidis ◽  
Late Onset ◽  
Gram Positive ◽  
Cytokine Responses ◽  
Inflammatory Protein ◽  
Late Onset Sepsis ◽  
Immunological Mechanisms ◽  
Factor Α

Abstract Background Late-onset sepsis (LOS) with Staphylococcus epidermidis is common in preterm infants, but the immunological mechanisms underlying heightened susceptibility are poorly understood. Our aim is to characterize the ontogeny of cytokine responses to live S. epidermidis in preterm infants with and without subsequent Gram-positive LOS. Methods We conducted a prospective, observational cohort study of preterm infants (&lt;30 weeks gestational age [GA]) with blood sampling on Days 1, 7, 14, 21, and 28 of life. Cytokine responses in peripheral whole blood stimulated with live S. epidermidis were analyzed by 11-plex immunoassay. Results Of 129 infants (mean GA, 26.2 weeks; mean birth weight, 887g), 23 (17.8%) had confirmed LOS with Gram-positive organisms and 15 (11.6%) had clinical sepsis, with median onsets at 13 and 15 days, respectively. Blood cytokine responses to an in vitro S. epidermidis challenge were similar between infected and uninfected infants on Day 1, but diverged thereafter. Infants with subsequent LOS displayed broadly reduced S. epidermidis–induced responses from Day 7 onwards, compared to those who did not develop LOS. This pattern was observed with chemokines (interleukin [IL]-8, monocyte chemotactic protein–1, and macrophage inflammatory protein–1α), pro-inflammatory cytokines (IL-1, IL-6, and tumor necrosis factor–α) and the regulatory cytokine IL-10. Conclusions Cytokine responses to a live S. epidermidis challenge are impaired in infants with LOS and precede the onset of clinical illness. Quantifying pathogen-specific cytokine responses at Day 7 may identify those high-risk preterm infants at the greatest risk of LOS, and prospective replication is warranted.

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