title: Use of scanning electron microscopy to investigate the prophylactic efficacy of rifampin-impregnated CSF shunt catheters.
abstract: Infection continues to be one of the major complications of cerebrospinal fluid (CSF) shunting procedures, and is caused mainly by skin-derived bacteria. Production of an extracellular biofilm plays an important role in the pathogenesis of shunt-associated infections by protecting bacteria from immune mechanisms and antibiotics. So far, removal of the original shunt and implantation of a new shunting device has been the only successful treatment for most patients. As an alternative strategy to prevent CSF infections, a rifampin-impregnated silicone catheter was designed to provide high initial and long-lasting (>60 days) release of bactericidal drug. To investigate the pathophysiological mechanism of its function, this new device was investigated both in vitro and in a rodent model of CSF infection by scanning electron microscopy (SEM) and bacterial culture. Staphylococcus epidermidis (10(8) cfu/ml) and S. aureus (10(4) cfu/ml) served as test strains. SEM demonstrated that, in contrast to the unloaded catheters, initial bacterial adherence on the catheter surface could be reduced to a few single cells, which did not show visible signs of proliferation. Bacterial cultures obtained simultaneously were all sterile, showing that adherent bacteria were killed immediately by the rifampin released from the catheter. Although rifampin incorporation into silicone polymers was not able to prevent initial bacterial adhesion completely, subsequent colonisation could be prevented.
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: R A
authors.initials: RA
authors.lastname: Kockro
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: J A
authors.initials: JA
authors.lastname: Hampl
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Jansen
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Peters
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Scheihing
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Giacomelli
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kunze
authors.affiliation: *Department of Neurosurgery, University of Heidelberg, †Department of Hygiene and Environmental Medicine, University of Mainz and ‡Institute of Medical Microbiology, University of Münster, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Aschoff
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D001422:Bacterial Adhesion; D001424:Bacterial Infections / Q000517:prevention & control*; D018441:Biofilms; D002408:Catheters, Indwelling / Q000382:microbiology* / Q000592:standards; D002557:Cerebrospinal Fluid Shunts / Q000592:standards*; D008855:Microscopy, Electron, Scanning; D011817:Rabbits; D011897:Random Allocation; D012293:Rifampin; D012826:Silicone Elastomers; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000648:ultrastructure; D013212:Staphylococcus epidermidis / Q000302:isolation & purification / Q000648:ultrastructure
chemical_list: D000900:Anti-Bacterial Agents; D012826:Silicone Elastomers; D012293:Rifampin