Microbial contamination of disinfectants used for intermittent self-catheterization.

We investigated the microbial contamination of 0.02% benzalkonium chloride solution used in catheter kits for intermittent self-catheterization. Of 20 samples examined, 12 (60.0%) were contaminated with 8.8 x 10(2)-3.1 x 10(6) colony-forming units (cfu)/mL. The contaminants were Pseudomonas fluorescens, Burkholderia cepacia, and Aeromonas spp. These results showed that 0.02% benzalkonium chloride solution used for the lubrication/disinfection of catheters for self-catheterization is susceptible to contamination. Therefore, the lubricant/disinfectant for catheters for self-catheterization was changed from 0.02% benzalkonium chloride solution to 84-87% glycerin containing 0.02% benzalkonium chloride, and microbial contamination of the latter in catheter kits for self-catheterization was reinvestigated. Of 42 samples, 5 (11.9%) were contaminated with 20-2.0 x 10(4) cfu/mL. However, the rate of contamination of 84-87% glycerin containing 0.02% benzalkonium chloride was significantly lower than that of 0.02% benzalkonium chloride solution (P<0.0001). The contaminant of 84-87% glycerin containing 0.02% benzalkonium chloride was Bacillus spp. in all contaminated samples. In this survey, neither contaminants of 0.02% benzalkonium chloride solution nor the contaminant of 84-87% glycerin containing 0.02% benzalkonium chloride were the causative microbial species of urinary tract infection.