The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
S. Lugauer - One of the best experts on this subject based on the ideXlab platform.
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Catheter-associated infections in urology: possible use of silver-impregnated Catheters and the Erlanger silver Catheter.
Infection, 1999Co-Authors: W. Rösch, S. LugauerAbstract:Indwelling urinary Catheters play a very important part in urology. However, their use is accompanied by a considerable increase in the risk of nosocomial urinary tract infections. The pathophysiological cause is ascribed to pathogens that adhere to the Catheter Surface, proliferate and produce a biofilm. In addition to aseptic techniques, modification of the Catheter material to confer antimicrobial activity plays an essential part in the prevention of Catheter-related urinary tract infections. The antimicrobial efficacy of silver against gram-positive and gram-negative bacteria is well known and amply shownin vitro. The efficacy of silver-impregnated Catheters is critically dependent on both the chemical structure of the incorporated silver and the way the silver has been combined with the basic Catheter material. Hence, clinical studies on silver-modified Catheters have so far given inconsistent results. The new technology of the Erlanger silver Catheter offers the opportunity of an effective reduction in Catheter-related infections.
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Catheter-associated infections in urology: possible use of silver-impregnated Catheters and the Erlanger silver Catheter.
Infection, 1999Co-Authors: W. Rösch, S. LugauerAbstract:Indwelling urinary Catheters play a very important part in urology. However, their use is accompanied by a considerable increase in the risk of nosocomial urinary tract infections. The pathophysiological cause is ascribed to pathogens that adhere to the Catheter Surface, proliferate and produce a biofilm. In addition to aseptic techniques, modification of the Catheter material to confer antimicrobial activity plays an essential part in the prevention of Catheter-related urinary tract infections. The antimicrobial efficacy of silver against gram-positive and gram-negative bacteria is well known and amply shownin vitro. The efficacy of silver-impregnated Catheters is critically dependent on both the chemical structure of the incorporated silver and the way the silver has been combined with the basic Catheter material. Hence, clinical studies on silver-modified Catheters have so far given inconsistent results. The new technology of the Erlanger silver Catheter offers the opportunity of an effective reduction in Catheter-related infections.
Donavon J Hess - One of the best experts on this subject based on the ideXlab platform.
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role of staphylococcus aureus protein a in adherence to silastic Catheters
Journal of Surgical Research, 2011Co-Authors: Michelle J Henrystanley, Melody M Shepherd, Carol L Wells, Donavon J HessAbstract:Background Communities of bacteria, termed biofilms, frequently develop on central venous Catheters, and bacterial contamination of central venous Catheters is the most common cause of nosocomial bloodstream infections. Little is known about the initial events in bacterial adherence to the Catheter Surface, and experiments were designed to clarify the role of staphylococcal protein A, serum, and immunoglobulin in adherence of Staphylococcus aureus to silastic Catheters. We hypothesized that S. aureus protein A in the presence of serum and immunoglobulin would alter S. aureus adherence to silastic Catheters. Materials and Methods Three strains of S. aureus with varying expression of staphylococcal protein A were incubated 15 min at room temperature with silastic Catheters, and bacterial adherence to the Catheter Surface was quantified. In addition, the effects of serum, albumin, and purified IgG on bacterial adherence were assessed. Results Both serum and albumin had an inhibitory effect on S. aureus adherence to the Catheter Surface, and protein A expression did not appreciably modulate these effects. Purified serum IgG also inhibited S. aureus adherence, with IgG having a greater inhibitory effect on the adherence of an S. aureus strain deficient in protein A compared with an S. aureus strain expressing high levels of protein A. Conclusion S. aureus adherence to silastic Catheters was inhibited by whole serum, albumin, and purified IgG. Expression of staphylococcal protein A interfered with IgG mediated inhibition of bacterial binding to the Catheter Surface. Protein A altered S. aureus adherence to silastic Catheters in the presence of immunoglobulin, but not in the presence of serum or albumin.
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ASSOCIATION FOR ACADEMIC SURGERY Role of Staphylococcus aureus Protein A in Adherence to Silastic Catheters 1
2011Co-Authors: Michelle J. Henry-stanley, Melody M Shepherd, Carol L Wells, Donavon J HessAbstract:Background. Communities of bacteria, termed biofilms, frequently develop on central venous Catheters, and bacterial contamination of central venous Catheters is the most common cause of nosocomial bloodstream infections. Little is known about the initial events in bacterial adherence to the Catheter Surface, and experiments were designed to clarify the role of staphylococcal protein A, serum, and immunoglobulin in adherence of Staphylococcus aureus to silastic Catheters. We hypothesized that S. aureus protein A in the presence of serum and immunoglobulin would alter S. aureus adherence to silastic Catheters. Materials and Methods. Three strains of S. aureus with varying expression of staphylococcal protein A were incubated 15 min at room temperature with silastic Catheters, and bacterial adherence to the Catheter Surface was quantified. In addition, the effects of serum, albumin, and purified IgG on bacterial adherence were assessed. Results. Both serum and albumin had an inhibitory effect on S. aureus adherence to the Catheter Surface, and protein A expression did not appreciably modulate these effects. Purified serum IgG also inhibited S. aureus adherence, with IgG having a greater inhibitory effect on the adherence of an S. aureus strain deficient in protein A compared with an S. aureus strain expressing high levels of protein A. Conclusion. S. aureus adherence to silastic Catheters was inhibited by whole serum, albumin, and purified IgG. Expression of staphylococcal protein A interfered with IgG mediated inhibition of bacterial binding to the Catheter Surface. Protein A altered S. aureus adherence to silastic Catheters in the presence of immunoglobulin, but not in the presence of se
Sean P. Gorman - One of the best experts on this subject based on the ideXlab platform.
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Relationship between biomedical Catheter Surface properties and lubricity as determined using textural analysis and multiple regression analysis.
Biomaterials, 2004Co-Authors: David S. Jones, Clare P. Garvin, Sean P. GormanAbstract:In this study, the Surface properties of and work required to remove 12 commercially available and developmental Catheters from a model biological medium (agar), a measure of Catheter lubricity, were characterised and the relationships between these properties were examined using multiple regression and correlation analysis. The work required for removal of Catheter sections (7 cm) from a model biological medium (1% w/w agar) were examined using tensile analysis. The water wettability of the Catheters were characterised using dynamic contact angle analysis, whereas Surface roughness was determined using atomic force microscopy. Significant differences in the ease of removal were observed between the various Catheters, with the silicone-based materials generally exhibiting the greatest ease of removal. Similarly, the Catheters exhibited a range of advancing and receding contact angles that were dependent on the chemical nature of each Catheter. Finally, whilst the microrugosities of the various Catheters differed, no specific relationship to the chemical nature of the biomaterial was apparent. Using multiple regression analysis, the relationship between ease of removal, receding contact angle and Surface roughness was defined as: Work done (N mm)=17.18+0.055 Rugosity (nm)-0.52 Receding contact angle ( degrees ) (r=0.49). Interestingly, whilst the relationship between ease of removal and Surface roughness was significant (r=0.48, p=0.0005), in which Catheter lubricity increased as the Surface roughness decreased, this was not the case with the relationship between ease of removal and receding contact angle (r=-0.18, p>0.05). This study has therefore uniquely defined the contributions of each of these Surface properties to Catheter lubricity. Accordingly, in the design of urethral Catheters, it is recommended that due consideration should be directed towards biomaterial Surface roughness to ensure maximal ease of Catheter removal. Furthermore, using the method described in this study, differences in the lubricity of the various Catheters were observed that may be apparent in their clinical use.
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Relationship between biomedical Catheter Surface properties and lubricity as determined using textural analysis and multiple regression analysis
Biomaterials, 2003Co-Authors: David S. Jones, Clare P. Garvin, Sean P. GormanAbstract:Abstract In this study, the Surface properties of and work required to remove 12 commercially available and developmental Catheters from a model biological medium (agar), a measure of Catheter lubricity, were characterised and the relationships between these properties were examined using multiple regression and correlation analysis. The work required for removal of Catheter sections (7 cm) from a model biological medium (1% w/w agar) were examined using tensile analysis. The water wettability of the Catheters were characterised using dynamic contact angle analysis, whereas Surface roughness was determined using atomic force microscopy. Significant differences in the ease of removal were observed between the various Catheters, with the silicone-based materials generally exhibiting the greatest ease of removal. Similarly, the Catheters exhibited a range of advancing and receding contact angles that were dependent on the chemical nature of each Catheter. Finally, whilst the microrugosities of the various Catheters differed, no specific relationship to the chemical nature of the biomaterial was apparent. Using multiple regression analysis, the relationship between ease of removal, receding contact angle and Surface roughness was defined as: Work done (N mm)=17.18+0.055 Rugosity (nm)−0.52 Receding contact angle (°) (r=0.49). Interestingly, whilst the relationship between ease of removal and Surface roughness was significant (r=0.48, p=0.0005), in which Catheter lubricity increased as the Surface roughness decreased, this was not the case with the relationship between ease of removal and receding contact angle (r=−0.18, p>0.05). This study has therefore uniquely defined the contributions of each of these Surface properties to Catheter lubricity. Accordingly, in the design of urethral Catheters, it is recommended that due consideration should be directed towards biomaterial Surface roughness to ensure maximal ease of Catheter removal. Furthermore, using the method described in this study, differences in the lubricity of the various Catheters were observed that may be apparent in their clinical use.
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Confocal laser scanning microscopy of peritoneal Catheter Surfaces.
Journal of medical microbiology, 1993Co-Authors: Sean P. Gorman, W. M. Mawhinney, Colin G. Adair, M. IssouckisAbstract:Summary. Surface topography of used (in situ > 12 months) and unused CAPD Catheters was studied by scanning electronmicroscopy (SEM) and confocal laser scanning microscopy (CLSM). Microbial biofilm was observed on all used Catheters. Disruption and removal of the attached biofilm revealed extensive pitting of the Catheter Surface and scoring within the Catheter pores. Similar, though less extensive, Surface defects were present in unused Catheters. Examination by CLSM, with software specific to the determination of Surface topography, showed used Catheters to have a Surface microrugosity greater than that of unused Catheters (p < 0·0005). Adherence studies with radiolabelled Staphylococcus epidermidis demonstrated increased adherence to used than to unused Catheters (p < 0·0005) after 48 h. However, when Catheters were pre-treated with spent dialysate there was a substantial reduction in bacterial adherence to either Catheter and no significant difference in adherence to used and unused Catheters. Surface microrugosity of CAPD Catheters increases during use but is unlikely to be an important factor in bacterial adherence in vivo.
Rabih O. Darouiche - One of the best experts on this subject based on the ideXlab platform.
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new strategies to prevent Catheter associated urinary tract infections
Nature Reviews Urology, 2012Co-Authors: Danish M Siddiq, Rabih O. DarouicheAbstract:Catheter-associated urinary tract infection (CAUTI) is the most common healthcare-associated infection worldwide. Here, Siddiq and Darouiche discuss the various methods of CAUTI prevention, including criteria for appropriate placement and early removal and strategies focusing on biocompatible Catheter materials that cause minimal host inflammatory response and retard biofilm formation. Catheter-associated urinary tract infection (CAUTI) is the most common health-care-associated infection worldwide. Although not all cases of bacteriuria result in clinical infection, several hundred thousand episodes of CAUTI occur each year in the USA alone. The milieu in which the Catheter is placed is highly conducive to bacterial colonization, biofilm formation on the Catheter Surface, and inevitable Catheter-associated bacteriuria. A multitude of novel methods of CAUTI prevention have been described, including established approaches that are routinely recommended, such as the use of a secured, closed, silicone urinary Catheter drainage system that mimics normal voiding, and newer strategies focusing on biocompatible Catheter materials that cause minimal host inflammatory response and retard biofilm formation. Much recent research has focused on modification of the Catheter Surface by either coating or impregnation with antimicrobials or antiseptics. However, clinical trials that analyse cost-effectiveness and rates of antimicrobial resistance are awaited. More recently, innovative use of iontophoresis, vibroacoustic stimulation, bacterial interference and bacteriophage cocktails has been reported.
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Colicins prevent colonization of urinary Catheters
The Journal of antimicrobial chemotherapy, 2005Co-Authors: Barbara W. Trautner, Richard A. Hull, Rabih O. DarouicheAbstract:Objectives: Natural microbial defence systems, such as bacteriocins, may be a novel means to prevent Catheter-associated urinary tract infection. We investigated in vitro whether a colicin-expressing strain of Escherichia coil could prevent urinary Catheter colonization by a colicin-susceptible, uropathgenic strain of E. coli. Methods: Segments of urinary Catheter were inoculated with colicin-producing E. coli K-12 and then exposed to either colicin-susceptible E. coli(a uropathogenic clinical isolate) or colicin-resistant E. coil (derived from the susceptible clinical isolate). Catheters were then incubated overnight, rinsed and sonicated. Results: The presence of colicin-producing E. coli K-12 on the Catheter Surface completely prevented Catheter colonization by colicin-susceptible E. coli but not by resistant E. coli. The colicin-susceptible strain but not the colicin-resistant strain also disappeared from broth cultures in the presence of colicin-producing E. coil K-12. Conclusions: The observed inhibition of Catheter colonization by the uropathogenic clinical isolate of E. coil can be attributed to the presence of a colicin-producing strain of E. coli on the Catheter Surface. Bacteriocin production by a non-pathogenic organism may have clinical applicability as a means to prevent Catheter-associated urinary tract infection.
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In vitro efficacy of antimicrobial-coated bladder Catheters in inhibiting bacterial migration along Catheter Surface.
The Journal of infectious diseases, 1997Co-Authors: Rabih O. Darouiche, Hossam Safar, Issam I RaadAbstract:Most cases of Catheter-related urinary tract infection are probably caused by organisms that migrate from the urethral meatus-Catheter interface along the external Surface of the Catheter into the bladder. To examine the ability of bladder Catheters coated with minocycline and rifampin to inhibit bacterial migration along the external Surface of the Catheter, a novel in vitro bladder model was used. Compared with uncoated Catheters, antimicrobial-coated bladder Catheters significantly impeded the migration of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis, and Candida albicans (bacteriuria developed at a mean of 2-5 days vs. 9-34 days, respectively, after bacterial contamination of the Catheter). Although production of zones of inhibition by coated Catheters may provide some protection against infection, there was no correlation between the size of zones of inhibition and level of efficacy in inhibiting bacterial migration in vitro. Examination of the clinical efficacy of these antimicrobial-coated bladder Catheters is prudent.
W. Rösch - One of the best experts on this subject based on the ideXlab platform.
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Catheter-associated infections in urology: possible use of silver-impregnated Catheters and the Erlanger silver Catheter.
Infection, 1999Co-Authors: W. Rösch, S. LugauerAbstract:Indwelling urinary Catheters play a very important part in urology. However, their use is accompanied by a considerable increase in the risk of nosocomial urinary tract infections. The pathophysiological cause is ascribed to pathogens that adhere to the Catheter Surface, proliferate and produce a biofilm. In addition to aseptic techniques, modification of the Catheter material to confer antimicrobial activity plays an essential part in the prevention of Catheter-related urinary tract infections. The antimicrobial efficacy of silver against gram-positive and gram-negative bacteria is well known and amply shownin vitro. The efficacy of silver-impregnated Catheters is critically dependent on both the chemical structure of the incorporated silver and the way the silver has been combined with the basic Catheter material. Hence, clinical studies on silver-modified Catheters have so far given inconsistent results. The new technology of the Erlanger silver Catheter offers the opportunity of an effective reduction in Catheter-related infections.
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Catheter-associated infections in urology: possible use of silver-impregnated Catheters and the Erlanger silver Catheter.
Infection, 1999Co-Authors: W. Rösch, S. LugauerAbstract:Indwelling urinary Catheters play a very important part in urology. However, their use is accompanied by a considerable increase in the risk of nosocomial urinary tract infections. The pathophysiological cause is ascribed to pathogens that adhere to the Catheter Surface, proliferate and produce a biofilm. In addition to aseptic techniques, modification of the Catheter material to confer antimicrobial activity plays an essential part in the prevention of Catheter-related urinary tract infections. The antimicrobial efficacy of silver against gram-positive and gram-negative bacteria is well known and amply shownin vitro. The efficacy of silver-impregnated Catheters is critically dependent on both the chemical structure of the incorporated silver and the way the silver has been combined with the basic Catheter material. Hence, clinical studies on silver-modified Catheters have so far given inconsistent results. The new technology of the Erlanger silver Catheter offers the opportunity of an effective reduction in Catheter-related infections.