Comparison of the efficacies of antibiotic-impregnated and silver-impregnated ventricular catheters on the prevention of infections. An in vitro laboratory study

Infection of the cerebrospinal fluid is a life-threatening condition which is usually treated with systemic antibiotics and continued ventricular drainage in children. The aim of this study was to analyze the antimicrobial activities of two antimicrobial-agent-impregnated ventricular catheters and to compare their efficacies on the bacterial cultures. Antibiotic-impregnated (clindamycin and rifampicin), silver-impregnated, and standard ventricular catheters were used in this study. The experiment was performed in 2 steps. In the first step, small pieces of the catheters were cut and incubated. Then, they were washed and placed in agar medium. Finally, the number of colonies was counted. In the second step, the pieces of catheters were placed on agar plates containing Staphylococcus aureus,Staphylococcus epidermidis, and Pseudomonas aeruginosa. The plates were incubated, and then, the inhibition zone for each catheter was measured. An inhibition zone was observed only in the plates for antibiotic-impregnated catheters. In the other plates, no inhibition zone was detected. The number of colonies was lowest in the plate with the silver-impregnated catheter, followed by the antibiotic-impregnated and standard catheters. The antibiotic-impregnated catheter seems more effective for antimicrobial treatment. Although no inhibition zone was found in the plates for silver-impregnated catheters, these catheters allow the lowest bacterial colonization in agar.