Figure 4.

Field testing of disinfectants in gnotobiotic isolators. (A) Ten agar plates freshly inoculated with E. coli were placed inside a gnotobiotic isolator in different locations: 6 on the floor (nos. 1 through 6), 2 on the sides (nos. 7 and 8), and 2 on the ceiling (nos. 9 and 10). The plates on the sides and ceiling contained sterilized metal washers in the agar and were held in place by magnets applied from the outside of the isolator. (B) Isolators were closed, inflated, and fogged for various times (1.5 to 6 min) by using different concentrations of the indicated disinfectants. After a 5-min incubation period without fogging and an additional 5-min exhaust period, plates were removed from the isolators and incubated overnight to promote growth of any remaining live bacteria. Disinfectant effectiveness is shown as the percentage of the plates in an isolator that showed bacterial growth. Each data point represents 1 experiment. Lines indicate the mean of each respective condition and disinfectant.