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C. W. Keevil - One of the best experts on this subject based on the ideXlab platform.
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Journal of Hospital Infection A cold water, ultrasonic activated stream efficiently removes proteins and prion-associated amyloid from Surgical Stainless Steel
Journal of Hospital Infection, 2020Co-Authors: T.j. Secker, R. Hervé, Timothy G. Leighton, Douglas G. Offin, Peter R. Birkin, C. W. KeevilAbstract:Summary Background Sterile Service Department decontamination procedures for Surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which utilises a low pressure ultrasonic activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants. Aim To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from Surgical Stainless Steel (SS) surfaces. Methods Test surfaces were contaminated with 22L, ME7 or 263K prion infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 seconds. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream. Findings Efficient removal of the different prion strains from the Surgical SS surfaces was observed, and reduced levels of protease sensitive and resistant prion protein was detected in recovered supernatant. Conclusions This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital acquired infections.
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Cold water cleaning of brain proteins, biofilm and bone – harnessing an ultrasonically activated stream
Physical Chemistry Chemical Physics, 2015Co-Authors: Peter R. Birkin, T.j. Secker, R. Hervé, Douglas G. Offin, Christopher J. B. Vian, Robert P. Howlin, Jonathan I. Dawson, Paul Stoodley, Richard O.c. Oreffo, C. W. KeevilAbstract:In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from Surgical Stainless Steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications.
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Efficacy of humidity retention bags for the reduced adsorption and improved cleaning of tissue proteins including prion-associated amyloid to Surgical Stainless Steel surfaces
Biofouling, 2015Co-Authors: T.j. Secker, H.e. Pinchin, R. Hervé, C. W. KeevilAbstract:Increasing drying time adversely affects attachment of tissue proteins and prion-associated amyloid to Surgical Stainless Steel, and reduces the efficacy of commercial cleaning chemistries. This study tested the efficacy of commercial humidity retention bags to reduce biofouling on Surgical Stainless Steel and to improve subsequent cleaning. Surgical Stainless Steel surfaces were contaminated with ME7-infected brain homogenates and left to dry for 15 to 1,440 min either in air, in dry polythene bags or within humidity retention bags. Residual contamination pre/post cleaning was analysed using Thioflavin T/SYPRO Ruby dual staining and microscope analysis. An increase in biofouling was observed with increased drying time in air or in sealed dry bags. Humidity retention bags kept both protein and prion-associated amyloid minimal across the drying times both pre- and post-cleaning. Therefore, humidity bags demonstrate a cheap, easy to implement solution to improve Surgical instrument reprocessing and to potentially reduce associated hospital acquired infections.
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Adsorption of prion and tissue proteins to Surgical Stainless Steel surfaces and the efficacy of decontamination following dry and wet storage conditions
Journal of Hospital Infection, 2011Co-Authors: T.j. Secker, R. Hervé, C. W. KeevilAbstract:Summary Iatrogenic transmission of the infectious prion protein (PrP Sc ) is a potential threat due to its resistance to many chemical and enzymatic decontamination protocols and its strong adhesive properties to Stainless Steel. The conditions in which Surgical instruments are handled during and after surgery may affect the level of tissue protein, prion attachment and the efficacy of subsequent decontamination regimes. This study investigated the adhesion of tissue protein and prion-associated amyloid to Surgical Stainless Steel with respect to time and various storage conditions, and the subsequent outcome on the efficacy of enzymatic cleaning chemistries. Surfaces were contaminated with ME7-infected brain homogenate and left to dry between 0 and 120 min at room temperature or 24 h, in dry or moist conditions. Residual contamination before and after cleaning was visualised using sensitive fluorescent staining and episcopic differential interference contrast/epifluorescence microscopy. Longer drying times increased both protein and prion amyloid adsorption and affected the efficacy of the cleaning chemistries tested. A moist environment post-contamination significantly reduced the attachment of both protein and prion amyloid to the Surgical Stainless Steel surface. Maintaining moist conditions could potentially improve the subsequent decontamination of reusable Surgical instruments, also reducing process time and cost.
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Current risk of iatrogenic Creutzfeld–Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neuroSurgical instruments
Journal of Hospital Infection, 2010Co-Authors: R. Hervé, T.j. Secker, C. W. KeevilAbstract:The initial cleaning of reusable Surgical devices is critical to ensure the efficacy of the subsequent sterilisation process. Transmissible spongiform encephalopathies (TSEs) are incurable and fatal neurodegenerative diseases apparently transmitted simply by the absorption or ingestion of self-aggregating protease-resistant prions (PrP(Sc)), which are very resilient to most standard cleaning chemistries and heat-based decontamination techniques. Therefore there is a risk of iatrogenic transmission from reusable Surgical devices if these are allowed to retain potentially infectious material after standard reprocessing through sterile service departments (SSDs). We aimed to assess the current state of Surgical instrument decontamination with the collaboration of anonymous SSDs. Surgical Stainless Steel surfaces were spiked with prion-infected brain homogenates, and episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy was applied to quantify the amount of residual prion amyloid and other proteins remaining after decontamination with enzymatic cleaners currently employed by SSDs. Reusable instruments deemed 'clean and ready to use' were also stained for comparison with our findings in the laboratory. All cleaning chemistries were only partially effective under the recommended conditions. More importantly, PrP(Sc) constituted the main fraction of the remaining contamination left on these surfaces. The neurosurgery instruments also harboured amyloid and general protein contamination. This study shows that currently marketed cleaning chemistries and recent decontamination protocols do not completely suppress the threat from iatrogenic CJD. These findings should be taken into account for risk assessment purposes and re-evaluating instrument handling and decontamination practices.
T.j. Secker - One of the best experts on this subject based on the ideXlab platform.
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Journal of Hospital Infection A cold water, ultrasonic activated stream efficiently removes proteins and prion-associated amyloid from Surgical Stainless Steel
Journal of Hospital Infection, 2020Co-Authors: T.j. Secker, R. Hervé, Timothy G. Leighton, Douglas G. Offin, Peter R. Birkin, C. W. KeevilAbstract:Summary Background Sterile Service Department decontamination procedures for Surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which utilises a low pressure ultrasonic activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants. Aim To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from Surgical Stainless Steel (SS) surfaces. Methods Test surfaces were contaminated with 22L, ME7 or 263K prion infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 seconds. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream. Findings Efficient removal of the different prion strains from the Surgical SS surfaces was observed, and reduced levels of protease sensitive and resistant prion protein was detected in recovered supernatant. Conclusions This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital acquired infections.
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Cold water cleaning of brain proteins, biofilm and bone – harnessing an ultrasonically activated stream
Physical Chemistry Chemical Physics, 2015Co-Authors: Peter R. Birkin, T.j. Secker, R. Hervé, Douglas G. Offin, Christopher J. B. Vian, Robert P. Howlin, Jonathan I. Dawson, Paul Stoodley, Richard O.c. Oreffo, C. W. KeevilAbstract:In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from Surgical Stainless Steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications.
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Efficacy of humidity retention bags for the reduced adsorption and improved cleaning of tissue proteins including prion-associated amyloid to Surgical Stainless Steel surfaces
Biofouling, 2015Co-Authors: T.j. Secker, H.e. Pinchin, R. Hervé, C. W. KeevilAbstract:Increasing drying time adversely affects attachment of tissue proteins and prion-associated amyloid to Surgical Stainless Steel, and reduces the efficacy of commercial cleaning chemistries. This study tested the efficacy of commercial humidity retention bags to reduce biofouling on Surgical Stainless Steel and to improve subsequent cleaning. Surgical Stainless Steel surfaces were contaminated with ME7-infected brain homogenates and left to dry for 15 to 1,440 min either in air, in dry polythene bags or within humidity retention bags. Residual contamination pre/post cleaning was analysed using Thioflavin T/SYPRO Ruby dual staining and microscope analysis. An increase in biofouling was observed with increased drying time in air or in sealed dry bags. Humidity retention bags kept both protein and prion-associated amyloid minimal across the drying times both pre- and post-cleaning. Therefore, humidity bags demonstrate a cheap, easy to implement solution to improve Surgical instrument reprocessing and to potentially reduce associated hospital acquired infections.
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Adsorption of prion and tissue proteins to Surgical Stainless Steel surfaces and the efficacy of decontamination following dry and wet storage conditions
Journal of Hospital Infection, 2011Co-Authors: T.j. Secker, R. Hervé, C. W. KeevilAbstract:Summary Iatrogenic transmission of the infectious prion protein (PrP Sc ) is a potential threat due to its resistance to many chemical and enzymatic decontamination protocols and its strong adhesive properties to Stainless Steel. The conditions in which Surgical instruments are handled during and after surgery may affect the level of tissue protein, prion attachment and the efficacy of subsequent decontamination regimes. This study investigated the adhesion of tissue protein and prion-associated amyloid to Surgical Stainless Steel with respect to time and various storage conditions, and the subsequent outcome on the efficacy of enzymatic cleaning chemistries. Surfaces were contaminated with ME7-infected brain homogenate and left to dry between 0 and 120 min at room temperature or 24 h, in dry or moist conditions. Residual contamination before and after cleaning was visualised using sensitive fluorescent staining and episcopic differential interference contrast/epifluorescence microscopy. Longer drying times increased both protein and prion amyloid adsorption and affected the efficacy of the cleaning chemistries tested. A moist environment post-contamination significantly reduced the attachment of both protein and prion amyloid to the Surgical Stainless Steel surface. Maintaining moist conditions could potentially improve the subsequent decontamination of reusable Surgical instruments, also reducing process time and cost.
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Current risk of iatrogenic Creutzfeld–Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neuroSurgical instruments
Journal of Hospital Infection, 2010Co-Authors: R. Hervé, T.j. Secker, C. W. KeevilAbstract:The initial cleaning of reusable Surgical devices is critical to ensure the efficacy of the subsequent sterilisation process. Transmissible spongiform encephalopathies (TSEs) are incurable and fatal neurodegenerative diseases apparently transmitted simply by the absorption or ingestion of self-aggregating protease-resistant prions (PrP(Sc)), which are very resilient to most standard cleaning chemistries and heat-based decontamination techniques. Therefore there is a risk of iatrogenic transmission from reusable Surgical devices if these are allowed to retain potentially infectious material after standard reprocessing through sterile service departments (SSDs). We aimed to assess the current state of Surgical instrument decontamination with the collaboration of anonymous SSDs. Surgical Stainless Steel surfaces were spiked with prion-infected brain homogenates, and episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy was applied to quantify the amount of residual prion amyloid and other proteins remaining after decontamination with enzymatic cleaners currently employed by SSDs. Reusable instruments deemed 'clean and ready to use' were also stained for comparison with our findings in the laboratory. All cleaning chemistries were only partially effective under the recommended conditions. More importantly, PrP(Sc) constituted the main fraction of the remaining contamination left on these surfaces. The neurosurgery instruments also harboured amyloid and general protein contamination. This study shows that currently marketed cleaning chemistries and recent decontamination protocols do not completely suppress the threat from iatrogenic CJD. These findings should be taken into account for risk assessment purposes and re-evaluating instrument handling and decontamination practices.
R. Hervé - One of the best experts on this subject based on the ideXlab platform.
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Journal of Hospital Infection A cold water, ultrasonic activated stream efficiently removes proteins and prion-associated amyloid from Surgical Stainless Steel
Journal of Hospital Infection, 2020Co-Authors: T.j. Secker, R. Hervé, Timothy G. Leighton, Douglas G. Offin, Peter R. Birkin, C. W. KeevilAbstract:Summary Background Sterile Service Department decontamination procedures for Surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which utilises a low pressure ultrasonic activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants. Aim To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from Surgical Stainless Steel (SS) surfaces. Methods Test surfaces were contaminated with 22L, ME7 or 263K prion infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 seconds. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream. Findings Efficient removal of the different prion strains from the Surgical SS surfaces was observed, and reduced levels of protease sensitive and resistant prion protein was detected in recovered supernatant. Conclusions This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital acquired infections.
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Cold water cleaning of brain proteins, biofilm and bone – harnessing an ultrasonically activated stream
Physical Chemistry Chemical Physics, 2015Co-Authors: Peter R. Birkin, T.j. Secker, R. Hervé, Douglas G. Offin, Christopher J. B. Vian, Robert P. Howlin, Jonathan I. Dawson, Paul Stoodley, Richard O.c. Oreffo, C. W. KeevilAbstract:In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from Surgical Stainless Steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications.
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Efficacy of humidity retention bags for the reduced adsorption and improved cleaning of tissue proteins including prion-associated amyloid to Surgical Stainless Steel surfaces
Biofouling, 2015Co-Authors: T.j. Secker, H.e. Pinchin, R. Hervé, C. W. KeevilAbstract:Increasing drying time adversely affects attachment of tissue proteins and prion-associated amyloid to Surgical Stainless Steel, and reduces the efficacy of commercial cleaning chemistries. This study tested the efficacy of commercial humidity retention bags to reduce biofouling on Surgical Stainless Steel and to improve subsequent cleaning. Surgical Stainless Steel surfaces were contaminated with ME7-infected brain homogenates and left to dry for 15 to 1,440 min either in air, in dry polythene bags or within humidity retention bags. Residual contamination pre/post cleaning was analysed using Thioflavin T/SYPRO Ruby dual staining and microscope analysis. An increase in biofouling was observed with increased drying time in air or in sealed dry bags. Humidity retention bags kept both protein and prion-associated amyloid minimal across the drying times both pre- and post-cleaning. Therefore, humidity bags demonstrate a cheap, easy to implement solution to improve Surgical instrument reprocessing and to potentially reduce associated hospital acquired infections.
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Adsorption of prion and tissue proteins to Surgical Stainless Steel surfaces and the efficacy of decontamination following dry and wet storage conditions
Journal of Hospital Infection, 2011Co-Authors: T.j. Secker, R. Hervé, C. W. KeevilAbstract:Summary Iatrogenic transmission of the infectious prion protein (PrP Sc ) is a potential threat due to its resistance to many chemical and enzymatic decontamination protocols and its strong adhesive properties to Stainless Steel. The conditions in which Surgical instruments are handled during and after surgery may affect the level of tissue protein, prion attachment and the efficacy of subsequent decontamination regimes. This study investigated the adhesion of tissue protein and prion-associated amyloid to Surgical Stainless Steel with respect to time and various storage conditions, and the subsequent outcome on the efficacy of enzymatic cleaning chemistries. Surfaces were contaminated with ME7-infected brain homogenate and left to dry between 0 and 120 min at room temperature or 24 h, in dry or moist conditions. Residual contamination before and after cleaning was visualised using sensitive fluorescent staining and episcopic differential interference contrast/epifluorescence microscopy. Longer drying times increased both protein and prion amyloid adsorption and affected the efficacy of the cleaning chemistries tested. A moist environment post-contamination significantly reduced the attachment of both protein and prion amyloid to the Surgical Stainless Steel surface. Maintaining moist conditions could potentially improve the subsequent decontamination of reusable Surgical instruments, also reducing process time and cost.
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Current risk of iatrogenic Creutzfeld–Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neuroSurgical instruments
Journal of Hospital Infection, 2010Co-Authors: R. Hervé, T.j. Secker, C. W. KeevilAbstract:The initial cleaning of reusable Surgical devices is critical to ensure the efficacy of the subsequent sterilisation process. Transmissible spongiform encephalopathies (TSEs) are incurable and fatal neurodegenerative diseases apparently transmitted simply by the absorption or ingestion of self-aggregating protease-resistant prions (PrP(Sc)), which are very resilient to most standard cleaning chemistries and heat-based decontamination techniques. Therefore there is a risk of iatrogenic transmission from reusable Surgical devices if these are allowed to retain potentially infectious material after standard reprocessing through sterile service departments (SSDs). We aimed to assess the current state of Surgical instrument decontamination with the collaboration of anonymous SSDs. Surgical Stainless Steel surfaces were spiked with prion-infected brain homogenates, and episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy was applied to quantify the amount of residual prion amyloid and other proteins remaining after decontamination with enzymatic cleaners currently employed by SSDs. Reusable instruments deemed 'clean and ready to use' were also stained for comparison with our findings in the laboratory. All cleaning chemistries were only partially effective under the recommended conditions. More importantly, PrP(Sc) constituted the main fraction of the remaining contamination left on these surfaces. The neurosurgery instruments also harboured amyloid and general protein contamination. This study shows that currently marketed cleaning chemistries and recent decontamination protocols do not completely suppress the threat from iatrogenic CJD. These findings should be taken into account for risk assessment purposes and re-evaluating instrument handling and decontamination practices.
G C Rajkumar - One of the best experts on this subject based on the ideXlab platform.
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Comparison between Stainless Steel staples and silk sutures for primary closure of skin in patients undergoing neck dissection: A comparative clinical study
Contemporary Clinical Dentistry, 2015Co-Authors: Abhishek Ghosh, Madan Nanjappa, Vaibhav Nagaraj, G C RajkumarAbstract:Introduction: Comparison between Stainless Steel staples and silk sutures for primary closure of skin in patients undergoing neck dissection, in context of rapid application, approximation of the skin edges, economy and aesthetics of the resultant scar. Aim: (1) To compare Surgical Stainless Steel staples and silk sutures for primary wound closure, with respect to presence/absence of wound infection and dehiscence (2) To compare the resultant scar following the two different methods of the closure at 3 rd month postoperatively with the help of visual analog scale and analyze the result statistically Design: This study was designed to compare skin closure using staples and silk sutures in patients undergoing neck dissection, using both methods in one-half of the same wound; thus each wound affording its own control. Materials and Methods: The study was conducted on patients requiring collar line incision (high submandibular incision) with or without a cephalad extension of midline lower lip split incision for Surgical access, who presented to the Department of Oral and Maxillo-Facial Surgery. (1) Sample size: 10 (2) Study design: Prospective Comparative study (3) Study duration: One and half years (4) Surgical Stainless Steel staples: Proximate Plus MD 35 W, Ethicon Endo Surgery (5) Sutures: 3-0 Ethiprime NW 5003, Non-Absorbable Surgical Suture, Mersilk-90 cm, Ethicon, (16 mm 3/8 circle cutting needle). Conclusion: It wass concluded that there is no significant difference between the scars observed in the regions of incision which underwent primary closure by two different methods, that is Surgical Stainless Steel staples and 3-0 Mersilk Sutures.
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Comparison between Stainless Steel staples and silk sutures for primary closure of skin in patients undergoing neck dissection: A comparative clinical study.
Contemporary clinical dentistry, 2015Co-Authors: Abhishek Ghosh, Madan Nanjappa, Vaibhav Nagaraj, G C RajkumarAbstract:Comparison between Stainless Steel staples and silk sutures for primary closure of skin in patients undergoing neck dissection, in context of rapid application, approximation of the skin edges, economy and aesthetics of the resultant scar. (1) To compare Surgical Stainless Steel staples and silk sutures for primary wound closure, with respect to presence/absence of wound infection and dehiscence (2) To compare the resultant scar following the two different methods of the closure at 3(rd) month postoperatively with the help of visual analog scale and analyze the result statistically This study was designed to compare skin closure using staples and silk sutures in patients undergoing neck dissection, using both methods in one-half of the same wound; thus each wound affording its own control. The study was conducted on patients requiring collar line incision (high submandibular incision) with or without a cephalad extension of midline lower lip split incision for Surgical access, who presented to the Department of Oral and Maxillo-Facial Surgery. (1) SAMPLE SIZE: 10 (2) STUDY DESIGN: Prospective Comparative study (3) Study duration: One and half years (4) Surgical Stainless Steel staples: Proximate Plus MD 35 W, Ethicon Endo Surgery (5) Sutures: 3-0 Ethiprime NW 5003, Non-Absorbable Surgical Suture, Mersilk-90 cm, Ethicon, (16 mm 3/8 circle cutting needle). It was concluded that there is no significant difference between the scars observed in the regions of incision which underwent primary closure by two different methods, that is Surgical Stainless Steel staples and 3-0 Mersilk Sutures.
Henk J. Busscher - One of the best experts on this subject based on the ideXlab platform.
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Electric block current induced detachment from Surgical Stainless Steel and decreased viability of Staphylococcus epidermidis
Biomaterials, 2005Co-Authors: Van Der Arnout Borden, H. C. Van Der Mei, Henk J. BusscherAbstract:In vitro Studies investigating the influence of electric DC current on bacterial detachment have demonstrated that continuous currents of only 25-125 mu A stimulated Staphylococcal strains to detach from Surgical Stainless Steel. However, DC Currents produce more power that has to be dissipated by the skin as compared to alternating currents. Also, an excess of ions on the Steel can Cause negative osteogenesis and fixation results. Therefore, it is the aim of this paper to examine whether detachment of Staphylococcus epidermidis from Stainless Steel Surfaces in a parallel plate flow chamber can also be Stimulated using electric block Currents. Block currents of 15, 60 and 100 mu A with different frequencies (0.1-2Hz) and duty cycles (5-50%) were applied to induce bacterial detachment. Block Currents of 100 mu A cause detachment of about 76% of adhering staphylococci from Stainless Steel, whereas in addition the remaining bacteria are less viable, as determined by culturing the remaining bacteria on agar plates. Therewith, block current-induced detachment of adhering bacteria from Stainless Steel appears to be an equally promising method to prevent infection of orthopaedic fixation pins and screws than application of DC Currents. (c) 2005 Elsevier Ltd. All rights reserved.
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ELECTRIC BLOCK CURRENT INDUCED DETACHMENT FROM Surgical Stainless Steel AND DECREASED VIABILITY OF STAPHYLOCOCCUS EPIDERMIDIS
2005Co-Authors: Van Der Arnout Borden, H. C. Van Der Mei, Henk J. BusscherAbstract:Introduction: Biomaterial implants in the human body constitute passive surfaces that are prone to bacterial adhesion as the on-set of biomaterials-associated infection. Antibiotic treatment of infected biomaterial implants is little successful clinically, because the biofilm-mode of growth protects the adhering organisms. Percutaneous implants, such as bone screws used in orthopedics or dental implants, constitute a special class of implants with infection rates exceeding the infection rate of deep body implants by far. Especially fixation frames, used in orthopedic surgery for the treatment of complicated fractures, inevitably become infected during the course of a treatment. The aim of this study is to determine whether it is possible to stimulate bacterial detachment from Surgical Stainless Steel and decrease the viability of the remaining adhering bacteria using block currents. Method: Bacteria were allowed to adhere from a flowing suspension of high ionic strength in a parallel plate flow chamber, after which the suspension was replaced by a bacterium free solution with 10 mM potassium phosphate buffer. Block currents of 15, 60 and 100 iA with different frequencies (0.1 to 2 Hz) and duty cycles (5 to 50%) were applied to induce bacterial detachment. Results: Initial detachment rate increased with increasing frequency and duty cycle, namely from 0 to 3700 cm −2 s −1 . The total detachment percentage for block currents of 100 iA with 25% to 50% duty cycle and frequencies as of 0.5 Hz are similar for all conditions. The detachment percentage in this range amounts on average 76%, whereas DC currents around 100 iA have an average of 60%, which was found to be significant lower (p=0.03). The killing capacity of these current series can be up to two log scales depending on the current. Conclusion: Current induced detachment of Staphylococcus epidermidis from Surgical Stainless Steel seems very effective, especially for a 100 iA, 50% duty cycle and 2 Hz block current. The viability of the remaining adhering bacteria decreased with 2 log scales. Clinically this could mean another way of preventing and curing pin tract infection.
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Electric current-induced detachment of Staphylococcus epidermidis biofilms from Surgical Stainless Steel.
Applied and Environmental Microbiology, 2004Co-Authors: Arnout J. Van Der Borden, Hester Van Der Werf, Henny C. Van Der Mei, Henk J. BusscherAbstract:Biomaterial-centered infections of orthopedic percutaneous implants are serious complications which can ultimately lead to osteomyelitis, with devastating effects on bone and surrounding tissues, especially since the biofilm mode of growth offers protection against antibiotics and since removal frequently is the only ultimate solution. Recently, it was demonstrated that as a possible pathway to prevent infections of percutaneous Stainless Steel implants, electric currents of 60 to 100 μA were effective at stimulating the detachment of initially adhering staphylococci from Surgical Stainless Steel. However, initially adhering bacteria are known to adhere more reversibly than bacteria growing in the later stages of biofilm formation. Hence, the aim of this study was to examine whether a growing Staphylococcus epidermidis biofilm can be stimulated to detach from Surgical Stainless Steel by the use of electric currents. In separate experiments, four currents, i.e., 60 and 100 μA of direct current (DC) and 60 and 100 μA of block current (50% duty cycle, 1 Hz), were applied for 360 min to stimulate the detachment of an S. epidermidis biofilm that had grown for 200 min. A 100-μA DC yielded 78% detachment, whereas a 100-μA block current under the same experimental conditions yielded only 31% detachment. The same trend was found for 60 μA, with 37% detachment for a DC and 24% for a block current. Bacteria remaining on the surface after the current application were less viable than they were prior to the current application, as demonstrated by confocal laser scanning microscopy. In conclusion, these results suggest that DCs are preferred for curing infections.
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Electric-current-induced detachment of Staphylococcus epidermidis strains from Surgical Stainless Steel.
Journal of Biomedical Materials Research Part B, 2004Co-Authors: Van Der Arnout Borden, Van Der Henny C. Mei, Henk J. BusscherAbstract:Infection of percutaneous biomaterials implants, such as fixation frames used for the repair of complicated fractures in orthopedics, is a major complication that almost inevitably leads to replacement of the implant. As antibiotic therapy usually has little impact on biomaterial-associated infections, it is the aim of this article to examine whether implant-associated Staphylococcus epidermidis and Staphylococcus aureus strains could be stimulated to detach from a Surgical Stainless Steel anode during application of an electric current. First, bacteria were allowed to adhere from a flowing suspension of physiological ionic strength in a parallel plate flow chamber to a Stainless-Steel surface, after which the suspension was replaced by a bacterium-free solution with a specified ionic strength (0.5-150-mM potassium phosphate). DC currents ranging from 15 to 125 microA were applied to induce bacterial detachment. Initial detachment decreased with increasing ionic strength at 100 microA. The percentage detachment achieved by application of an electric current after 2.5 h was highest (95%) in 1-mM potassium phosphate and decreased to 15% when the ionic strength exceeded 40 mM. The electric current did not significantly affect the percentage detachment, but initial detachment rates increased with increasing current from 1000 cm(-2) s(-1) at 15 microA to 7000 cm(-2) s(-1) at 125 microA. Although different isolates of S. epidermidis and S. aureus showed different patterns of current-induced detachment, all strains could be stimulated to detach. The results of this study define ionic-strength conditions and electric currents yielding staphylococcal detachment from Surgical Stainless Steel and therewith point to a pathway for the treatment and prevention of percutaneous metal-implant infection.