title: Investigation of biofilm formation on a charged intravenous catheter relative to that on a similar but uncharged catheter.
abstract: Catheter-related blood stream infections increase morbidity, mortality, and costs. This study investigated whether Certofix(®) protect antimicrobial catheters carry a surface charge and whether this inhibits biofilm formation. The capacitance of the catheter surfaces was measured and, to determine if the catheters released ions, distilled water was passed through and current measured as a function of voltage. With probes touching the inner and outer surfaces, capacitance was not voltage-dependent, indicating surfaces were uncharged or carried a similar charge. When one probe penetrated the catheter wall, capacitance was weakly voltage-dependent, indicating the presence of a surface charge. Standard and charged catheters were also exposed to phosphate buffered saline as controls or 2×10(6) colony forming units/mL (in phosphate buffered saline) of six different microorganisms for 60 or 120 minutes. When the growth of detached bacteria was measured, biofilm formation was significantly reduced, (P<0.05), for charged catheters for all organisms.
authors.affiliation: Department of Critical Care, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa ; Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Guy A
authors.initials: GA
authors.lastname: Richards
authors.affiliation: Department of Clinical Microbiology, Ampath National Laboratory Services, Milpark Hospital, Johannesburg, South Africa.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Brink
authors.affiliation: Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Ross
authors.initials: R
authors.lastname: McIntosh
authors.affiliation: Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, University of Pretoria, Pretoria, South Africa ; National Health Laboratory Service, Pretoria, South Africa.
authors.forename: Helen C
authors.initials: HC
authors.lastname: Steel
authors.affiliation: Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, University of Pretoria, Pretoria, South Africa ; National Health Laboratory Service, Pretoria, South Africa.
authors.forename: Riana
authors.initials: R
authors.lastname: Cockeran
keywords: biofilm; central venous catheters; electrical charge