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Robert J Sherertz - One of the best experts on this subject based on the ideXlab platform.
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Pathogenesis of Vascular Catheter Infection
Infections Associated with Indwelling Medical Devices, 2014Co-Authors: Robert J SherertzAbstract:The pathogenesis of vascular Catheter Infections has recently been extensively reviewed. This chapter summarizes existing understandings and presents details of new work published on vascular Catheter Infections since the recent reviews. Many factors have been shown to affect the risk of Catheters becoming infected. These include the unique abilities of certain organisms, Staphylococcus epidermidis, Staphylococcus aureus, and Candida albicans, to cause Catheter-related Infections. Molecular typing studies increasingly are improving our understanding of the pathogenesis of S. epidermidis/CoNS Catheter-related Infection. Recent studies with isogenic S. epidermidis mutants increasingly suggest that production of a polysaccharide adhesin is crucial to the pathogenesis of foreign-body Infection. This polysaccharide, first named PS/A, was initially described as a virulence factor in association with work examining the pathogenesis of endocarditis. Two additional findings of relevance to the pathogenesis of endocarditis and possibly vascular Catheter Infections are that binding to platelets facilitates endocarditis and S. aureus strains causing endocarditis are much more likely to be resistant to platelet microbicidal proteins. The pathogenesis of Catheter-related thrombosis has been studied in greater depth in recent years. With peripheral Catheters, ultrasonographic imaging has shown that early thrombus formation ( 24 h after insertion) occurs near the Catheter tip. Recent in vitro studies have shown that surface manipulations of polyurethane can lead to differences in protein and platelet deposition with associated differences in bacterial adherence.
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Prolonged Antimicrobial Activity of a Catheter Containing Chlorhexidine-Silver Sulfadiazine Extends Protection against Catheter Infections In Vivo
Antimicrobial agents and chemotherapy, 2001Co-Authors: Stefano Bassetti, Ralph B. D'agostino, Robert J SherertzAbstract:The present study evaluated in vitro and in vivo a new chlorhexidine (C)-silver sulfadiazine (S) vascular Catheter (the CS2 Catheter) characterized by a higher C content and by the extended release of the surface-bound antimicrobials. The CS2 Catheter was compared with a first-generation, commercially available CS Catheter (the CS1 Catheter). The CS2 Catheter produced slightly smaller zones of inhibition (mean difference, 0.9 mm [ P Staphylococcus aureus and five other microorganisms by several different methodologies. However, in a rabbit model, both CS Catheters were similarly efficacious in preventing a Catheter Infection when the rabbits were inoculated with 10 4 to 10 7 CFU of S. aureus at the time of Catheter insertion. The CS2 Catheter retained its antimicrobial activity significantly longer in vitro and in vivo (half-lifes exceeded 34 and 7 days, respectively) and was also significantly more efficacious in preventing a Catheter Infection when 10 6 CFU of S. aureus was inoculated 2 days after Catheter implantation ( P
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education of physicians in training can decrease the risk for vascular Catheter Infection
Annals of Internal Medicine, 2000Co-Authors: Robert J Sherertz, Wesley E Ely, Debi M Westbrook, Kate S Gledhill, Stephen A Streed, Betty Kiger, Lenora Flynn, Stewart Hayes, Sallie Strong, Julia M CruzAbstract:Physicians-in-training participated in a course designed to standardize Infection control practices. This course proved to be cost-effective and was associated with improved sterile technique and a...
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diagnosis of triple lumen Catheter Infection comparison of roll plate sonication and flushing methodologies
Journal of Clinical Microbiology, 1997Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I RaadAbstract:In a recent clinical trial, 248 triple-lumen Catheters were removed from patients in an intensive care unit, and their tip and subcutaneous segments were cultured by both the sonication and roll plate methods; for 191 of these Catheters, flush cultures of all three Catheter lumens were also performed. Previously published quantitative endpoints were used to define significant Catheter colonization. By using a composite index as a definition of colonization (any of the seven types of cultures meeting quantitative criteria), sonication of the subcutaneous segment was the most sensitive at detecting colonization (58%), followed by sonication of the Catheter tip (53%). Sonication of both the subcutaneous and tip segments was 20% more sensitive than sonication of an adjacent Catheter segment by the roll plate method (P < 0.05). The greater sensitivity of the sonication method could be attributed to its greater ability than the roll plate method to detect Catheter lumen colonization (82 versus 57%, respectively; P = 0.01). A greater number of positive Catheter segment cultures were found for colonized Catheters from patients with associated bacteremia than for colonized Catheters from patients without bacteremia (57 versus 37%; P = 0.004), making any culture method more likely to identify them. For Catheters with significant colonization of only one site, the localization was as follows: 36.7% subcutaneous segment, 36.7% Catheter lumen, and 26.6% tip segment. These findings suggest that the current practice of culturing a single segment of a central vascular Catheter is inadequate and needs to be reexamined. They further suggest that initial colonization of the Catheter lumen and tip segments may be more important than previously thought and may require a change in thinking of strategies designed to prevent Catheter Infection.
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Gamma radiation-sterilized, triple-lumen Catheters coated with a low concentration of chlorhexidine were not efficacious at preventing Catheter Infections in intensive care unit patients.
Antimicrobial agents and chemotherapy, 1996Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I Raad, Lane Gentry, David L. Bowton, Phillip E. Scuderi, William A. Carruth, Bhagyalaxmi Satishchandra, Judith PepeAbstract:In a randomized, double-blind trial, gamma radiation-sterilized, chlorhexidine-coated triple-lumen Catheters were compared with uncoated control Catheters for their ability to prevent Catheter Infection in 254 intensive care unit patients. The chlorhexidine coating was not efficacious, and a rabbit model demonstrated that reduction of chlorhexidine activity by gamma radiation sterilization was the likely explanation for the failure.
Samuel D Smith - One of the best experts on this subject based on the ideXlab platform.
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fibrin sheath enhances central venous Catheter Infection
Critical Care Medicine, 2002Co-Authors: John R Mehall, Daniel A Saltzman, Richard J Jackson, Samuel D SmithAbstract:OBJECTIVE: To determine whether fibrin-coated central venous Catheters have a higher Infection rate, and spawn more septic emboli, than uncoated Catheters after exposure to bacteremia. DESIGN: Animal study comparing Catheter Infection and blood cultures of fibrin-coated and uncoated Catheters exposed to bacteremia. SETTING: Animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: A total of 210 rats had Catheters placed with the proximal end buried subcutaneously. Rats were divided into three groups: tail vein bacterial injection on day 0 (no fibrin group) or on day 10 (fibrin group), or no injection/saline injection (control, n = 40). Bacterial injections were 1 x 108 colony forming units of either Staphylococcus epidermidis (n = 100) or Enterobacter cloacae (n = 60). Animals were killed 3 days after injection. Blood cultures were obtained via cardiac puncture, and Catheters were removed via the chest. Half of the Catheter was rolled onto agar and the other half was placed in trypticase soy broth. Plates and broth were incubated at 37 degrees C for 48 hrs. The presence of >15 colonies on roll plates, or growth in broth, was accepted as a positive sign of Infection. Microscopy was performed on day 20-10 Catheters. Thirty animals without Catheters had bacterial injections and underwent blood culture 3 days after injection. MEASUREMENTS AND MAIN RESULTS: Catheter Infection with S. epidermidis occurred in 32% of roll plates and 80% of broth from the fibrin group vs. 4% and 20% from the no fibrin group (p <.01 for each). Catheter Infection with E. cloacae occurred in 50% of roll plates and 80% of broth from the fibrin group vs. 0% and 12% from the no fibrin group (p <.01 for each). Positive blood cultures occurred in 47 of 68 animals from the fibrin group vs. 8 of 68 from the no fibrin group (p <.01). Microscopy showed a fibrin sheath on 20 of 20 Catheters. Without Catheters, 30 of 30 blood cultures were negative. CONCLUSION: The fibrin sheath significantly enhanced Catheter-related Infection and persistent bacteremia.
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Fibrin sheath enhances central venous Catheter Infection.
Critical care medicine, 2002Co-Authors: John R Mehall, Daniel A Saltzman, Richard J Jackson, Samuel D SmithAbstract:OBJECTIVE: To determine whether fibrin-coated central venous Catheters have a higher Infection rate, and spawn more septic emboli, than uncoated Catheters after exposure to bacteremia. DESIGN: Animal study comparing Catheter Infection and blood cultures of fibrin-coated and uncoated Catheters exposed to bacteremia. SETTING: Animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: A total of 210 rats had Catheters placed with the proximal end buried subcutaneously. Rats were divided into three groups: tail vein bacterial injection on day 0 (no fibrin group) or on day 10 (fibrin group), or no injection/saline injection (control, n = 40). Bacterial injections were 1 x 108 colony forming units of either Staphylococcus epidermidis (n = 100) or Enterobacter cloacae (n = 60). Animals were killed 3 days after injection. Blood cultures were obtained via cardiac puncture, and Catheters were removed via the chest. Half of the Catheter was rolled onto agar and the other half was placed in trypticase soy broth. Plates and broth were incubated at 37 degrees C for 48 hrs. The presence of >15 colonies on roll plates, or growth in broth, was accepted as a positive sign of Infection. Microscopy was performed on day 20-10 Catheters. Thirty animals without Catheters had bacterial injections and underwent blood culture 3 days after injection. MEASUREMENTS AND MAIN RESULTS: Catheter Infection with S. epidermidis occurred in 32% of roll plates and 80% of broth from the fibrin group vs. 4% and 20% from the no fibrin group (p
Issam I Raad - One of the best experts on this subject based on the ideXlab platform.
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a prospective crossover randomized trial of novobiocin and rifampin prophylaxis for the prevention of intravascular Catheter Infections in cancer patients treated with interleukin 2
Cancer, 1998Co-Authors: Issam I Raad, Y Ray M D Hachem, Dima Abisaid, V Kenneth M D Rolston, M Estella D Whimbey, C Antonio M D Buzaid, M Sewa D LeghaAbstract:BACKGROUND The aim of this study was to determine the efficacy of novobiocin and rifampin as oral antibiotic prophylaxis for the prevention of Catheter-related Infection in melanoma patients treated with interleukin-2 (IL-2) plus interferon-α and chemotherapy (biochemotherapy). METHODS Patients with advanced melanoma who were treated with biochemotherapy at the University of Texas M. D. Anderson Cancer Center were randomized in a crossover study to receive either oral antibiotic prophylaxis consisting of novobiocin and rifampin or observation alone over a 35-day course period. Patients were subsequently "crossed over" to the opposite arm of the study for an additional 35-day period, with each serving as his or her own control. RESULTS Twenty-six patients were enrolled. Nine patients (35%) failed to tolerate oral antibiotics because of severe nausea and vomiting; 17 patients (65%) were crossed over and considered evaluable. During the control patient courses, 71% of evaluable patients had infectious complications, 41% had a Catheter-associated bacteremia, and 53% had a local Catheter Infection. In contrast, of the patients treated with antibiotic prophylaxis, only 12% had an infectious complication (P = 0.001), 12% had a local Catheter Infection (P = 0.008), and 6% had Catheter-associated bacteremias (P = 0.04). Thirty-six episodes of Catheter Infections occurred during the 17 control courses, whereas only 3 episodes occurred during antibiotic prophylaxis (P < 0.001). CONCLUSIONS Although more than one-third of patients receiving IL-2 treatment with biochemotherapy failed to tolerate novobiocin and rifampin, this oral antibiotic regimen was efficacious in preventing the infectious complications, especially those associated with vascular Catheters, in this high risk patient population. Cancer 1998;82:403-11. © 1998 American Cancer Society.
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diagnosis of triple lumen Catheter Infection comparison of roll plate sonication and flushing methodologies
Journal of Clinical Microbiology, 1997Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I RaadAbstract:In a recent clinical trial, 248 triple-lumen Catheters were removed from patients in an intensive care unit, and their tip and subcutaneous segments were cultured by both the sonication and roll plate methods; for 191 of these Catheters, flush cultures of all three Catheter lumens were also performed. Previously published quantitative endpoints were used to define significant Catheter colonization. By using a composite index as a definition of colonization (any of the seven types of cultures meeting quantitative criteria), sonication of the subcutaneous segment was the most sensitive at detecting colonization (58%), followed by sonication of the Catheter tip (53%). Sonication of both the subcutaneous and tip segments was 20% more sensitive than sonication of an adjacent Catheter segment by the roll plate method (P < 0.05). The greater sensitivity of the sonication method could be attributed to its greater ability than the roll plate method to detect Catheter lumen colonization (82 versus 57%, respectively; P = 0.01). A greater number of positive Catheter segment cultures were found for colonized Catheters from patients with associated bacteremia than for colonized Catheters from patients without bacteremia (57 versus 37%; P = 0.004), making any culture method more likely to identify them. For Catheters with significant colonization of only one site, the localization was as follows: 36.7% subcutaneous segment, 36.7% Catheter lumen, and 26.6% tip segment. These findings suggest that the current practice of culturing a single segment of a central vascular Catheter is inadequate and needs to be reexamined. They further suggest that initial colonization of the Catheter lumen and tip segments may be more important than previously thought and may require a change in thinking of strategies designed to prevent Catheter Infection.
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Gamma radiation-sterilized, triple-lumen Catheters coated with a low concentration of chlorhexidine were not efficacious at preventing Catheter Infections in intensive care unit patients.
Antimicrobial agents and chemotherapy, 1996Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I Raad, Lane Gentry, David L. Bowton, Phillip E. Scuderi, William A. Carruth, Bhagyalaxmi Satishchandra, Judith PepeAbstract:In a randomized, double-blind trial, gamma radiation-sterilized, chlorhexidine-coated triple-lumen Catheters were compared with uncoated control Catheters for their ability to prevent Catheter Infection in 254 intensive care unit patients. The chlorhexidine coating was not efficacious, and a rabbit model demonstrated that reduction of chlorhexidine activity by gamma radiation sterilization was the likely explanation for the failure.
John R Mehall - One of the best experts on this subject based on the ideXlab platform.
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fibrin sheath enhances central venous Catheter Infection
Critical Care Medicine, 2002Co-Authors: John R Mehall, Daniel A Saltzman, Richard J Jackson, Samuel D SmithAbstract:OBJECTIVE: To determine whether fibrin-coated central venous Catheters have a higher Infection rate, and spawn more septic emboli, than uncoated Catheters after exposure to bacteremia. DESIGN: Animal study comparing Catheter Infection and blood cultures of fibrin-coated and uncoated Catheters exposed to bacteremia. SETTING: Animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: A total of 210 rats had Catheters placed with the proximal end buried subcutaneously. Rats were divided into three groups: tail vein bacterial injection on day 0 (no fibrin group) or on day 10 (fibrin group), or no injection/saline injection (control, n = 40). Bacterial injections were 1 x 108 colony forming units of either Staphylococcus epidermidis (n = 100) or Enterobacter cloacae (n = 60). Animals were killed 3 days after injection. Blood cultures were obtained via cardiac puncture, and Catheters were removed via the chest. Half of the Catheter was rolled onto agar and the other half was placed in trypticase soy broth. Plates and broth were incubated at 37 degrees C for 48 hrs. The presence of >15 colonies on roll plates, or growth in broth, was accepted as a positive sign of Infection. Microscopy was performed on day 20-10 Catheters. Thirty animals without Catheters had bacterial injections and underwent blood culture 3 days after injection. MEASUREMENTS AND MAIN RESULTS: Catheter Infection with S. epidermidis occurred in 32% of roll plates and 80% of broth from the fibrin group vs. 4% and 20% from the no fibrin group (p <.01 for each). Catheter Infection with E. cloacae occurred in 50% of roll plates and 80% of broth from the fibrin group vs. 0% and 12% from the no fibrin group (p <.01 for each). Positive blood cultures occurred in 47 of 68 animals from the fibrin group vs. 8 of 68 from the no fibrin group (p <.01). Microscopy showed a fibrin sheath on 20 of 20 Catheters. Without Catheters, 30 of 30 blood cultures were negative. CONCLUSION: The fibrin sheath significantly enhanced Catheter-related Infection and persistent bacteremia.
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Fibrin sheath enhances central venous Catheter Infection.
Critical care medicine, 2002Co-Authors: John R Mehall, Daniel A Saltzman, Richard J Jackson, Samuel D SmithAbstract:OBJECTIVE: To determine whether fibrin-coated central venous Catheters have a higher Infection rate, and spawn more septic emboli, than uncoated Catheters after exposure to bacteremia. DESIGN: Animal study comparing Catheter Infection and blood cultures of fibrin-coated and uncoated Catheters exposed to bacteremia. SETTING: Animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: A total of 210 rats had Catheters placed with the proximal end buried subcutaneously. Rats were divided into three groups: tail vein bacterial injection on day 0 (no fibrin group) or on day 10 (fibrin group), or no injection/saline injection (control, n = 40). Bacterial injections were 1 x 108 colony forming units of either Staphylococcus epidermidis (n = 100) or Enterobacter cloacae (n = 60). Animals were killed 3 days after injection. Blood cultures were obtained via cardiac puncture, and Catheters were removed via the chest. Half of the Catheter was rolled onto agar and the other half was placed in trypticase soy broth. Plates and broth were incubated at 37 degrees C for 48 hrs. The presence of >15 colonies on roll plates, or growth in broth, was accepted as a positive sign of Infection. Microscopy was performed on day 20-10 Catheters. Thirty animals without Catheters had bacterial injections and underwent blood culture 3 days after injection. MEASUREMENTS AND MAIN RESULTS: Catheter Infection with S. epidermidis occurred in 32% of roll plates and 80% of broth from the fibrin group vs. 4% and 20% from the no fibrin group (p
Stephen O Heard - One of the best experts on this subject based on the ideXlab platform.
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diagnosis of triple lumen Catheter Infection comparison of roll plate sonication and flushing methodologies
Journal of Clinical Microbiology, 1997Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I RaadAbstract:In a recent clinical trial, 248 triple-lumen Catheters were removed from patients in an intensive care unit, and their tip and subcutaneous segments were cultured by both the sonication and roll plate methods; for 191 of these Catheters, flush cultures of all three Catheter lumens were also performed. Previously published quantitative endpoints were used to define significant Catheter colonization. By using a composite index as a definition of colonization (any of the seven types of cultures meeting quantitative criteria), sonication of the subcutaneous segment was the most sensitive at detecting colonization (58%), followed by sonication of the Catheter tip (53%). Sonication of both the subcutaneous and tip segments was 20% more sensitive than sonication of an adjacent Catheter segment by the roll plate method (P < 0.05). The greater sensitivity of the sonication method could be attributed to its greater ability than the roll plate method to detect Catheter lumen colonization (82 versus 57%, respectively; P = 0.01). A greater number of positive Catheter segment cultures were found for colonized Catheters from patients with associated bacteremia than for colonized Catheters from patients without bacteremia (57 versus 37%; P = 0.004), making any culture method more likely to identify them. For Catheters with significant colonization of only one site, the localization was as follows: 36.7% subcutaneous segment, 36.7% Catheter lumen, and 26.6% tip segment. These findings suggest that the current practice of culturing a single segment of a central vascular Catheter is inadequate and needs to be reexamined. They further suggest that initial colonization of the Catheter lumen and tip segments may be more important than previously thought and may require a change in thinking of strategies designed to prevent Catheter Infection.
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Gamma radiation-sterilized, triple-lumen Catheters coated with a low concentration of chlorhexidine were not efficacious at preventing Catheter Infections in intensive care unit patients.
Antimicrobial agents and chemotherapy, 1996Co-Authors: Robert J Sherertz, Stephen O Heard, Issam I Raad, Lane Gentry, David L. Bowton, Phillip E. Scuderi, William A. Carruth, Bhagyalaxmi Satishchandra, Judith PepeAbstract:In a randomized, double-blind trial, gamma radiation-sterilized, chlorhexidine-coated triple-lumen Catheters were compared with uncoated control Catheters for their ability to prevent Catheter Infection in 254 intensive care unit patients. The chlorhexidine coating was not efficacious, and a rabbit model demonstrated that reduction of chlorhexidine activity by gamma radiation sterilization was the likely explanation for the failure.