Microwave sterilization: a method for home sterilization of urinary catheters

A standard microwave oven has been used to sterilize catheters used for intermittent self-catheterization. Catheters were incubated for 60 minutes in a suspension of microorganisms isolated from the urine of patients with urinary tract infections. Each catheter was removed from the suspension, placed in a paper bag and microwaved for 0 to 30 minutes. A control catheter was not microwaved. We tested 42 strains of microorganisms to determine the minimum microwaving time needed to sterilize the catheters. Representative urinary isolates of Escherichia coli, and Klebsiella, Proteus, Enterobacter, Pseudomonas, Staphylococcus, Streptococcus and Candida species were tested. Mean sterilization time for all strains was 13.0 minutes (standard deviation +/- 5.7 minutes), with a range of 4.0 to 28.6 minutes. Repeat sterilization in the microwave oven did not affect the integrity of the catheter. A water heat sink of constant volume was required. A home microwave oven may be used as a method to sterilize red rubber catheters for reuse. This technique makes aseptic intermittent self-catheterization a practical possibility.