Nonfermenters under the influence: ethanol disinfection of a saline dispenser caused misidentification by the Vitek 2 system using the new GN cards.

摘要

Because we suspected that residual ethanol in or on parts of the dispenser interfered with bacterial identification, we took samples from a bottle of saline solution to culture them for contaminants and to test them for the presence of ethanol. This bottle had been in use for 2 days, meaning that on two consecutive mornings it had been connected to the freshly rinsed dispenser. No contaminants could be demonstrated in the saline. However, ethanol was detected in a concentration of 0.4 g/liter (0.4 promille), which is consistent with 250 muul of 80 ethanol in a 500-ml saline bottle (5 to 6 drops). We subsequently inoculated GN cards with four different strains of P. aeruginosa and three different strains of A. baumannii from suspensions containing concentrations of ethanol ranging from 0 to 0.4 g/liter.