Biofilm-related infections of cerebrospinal fluid shunts

Abstract

Cerebrospinal fluid (CSF) shunts carry a high risk of complications. Infections represent a major cause of shunt failure. Diagnosis and therapy of such infections are complicated by the formation of bacterial biofilms attached to shunt surfaces. This study correlated the pathophysiology and clinical course of biofilm infections with microscopical findings on the respective shunts. Surface irregularities, an important risk-factor for shunt colonisation with bacteria, were found to increase over time because of silicone degradation. Scanning electron-microscopy (SEM) documented residual biological material (dead biofilm), which can further promote extant bacterial adhesion, on newly manufactured shunts. Clinical course and SEM both documented bacterial dissemination against CSF flow and the monodirectional valve. In all cases, biofilms grew on both the inner and outer surfaces of the shunts. Microscopy and conventional culture detected all bacterial shunt infections. Analyses of 16S rDNA sequences using conserved primers identified bacteria in only one of three cases, probably because of previous formalin fixation of the samples.

Biofilm-Infected Intracerebroventricular Shunts Elicit Inflammation within the Central Nervous System

“…aureus, mimicking what is seen in humans with ventricular shunt infections (14). Mice implanted with infected catheters demonstrated more pronounced innate immune cell infiltrates and elevated proinflammatory cytokine and chemokine levels compared to those implanted with sterile catheters.…”

“…Unfortunately, 30 to 40% of all CSF shunts in pediatric patients fail within the first year, resulting in a shunt revision to primary placement ratio of 3:1 in many health care centers (14,29). One of the most common causes of shunt failure is infection, reported in 5 to 30% of cases (14).…”

“…Unfortunately, 30 to 40% of all CSF shunts in pediatric patients fail within the first year, resulting in a shunt revision to primary placement ratio of 3:1 in many health care centers (14,29). One of the most common causes of shunt failure is infection, reported in 5 to 30% of cases (14). In addition to causing shunt failure, these catheter infections are associated with a higher risk of seizures, decreased intellectual performance, and a 2-fold increase in long-term mortality (14).…”

“…One of the most common causes of shunt failure is infection, reported in 5 to 30% of cases (14). In addition to causing shunt failure, these catheter infections are associated with a higher risk of seizures, decreased intellectual performance, and a 2-fold increase in long-term mortality (14). Therefore, studies designed to advance our understanding as to how bacteria colonize these catheters and evade antimicrobial killing in the central nervous system could have a dramatic impact on the development of treatment modalities for these serious infections.…”

“…The most common organisms responsible for central nervous system catheter infections, Staphylococcus epidermidis and Staphylococcus aureus, are both known to form biofilms (14,25). Biofilms are organized communities of bacteria that attach and aggregate on the catheter surface.…”