1219. Disinfection of Surfaces Contaminated with Carbapenemase Producing Acinetobacter baumannii Using Ozone Under Complex Room Conditions

BACKGROUND: Acinetobacter baumannii is an emerging multiresistant Gram-negative rod, which has caused multiple hospital outbreaks. A. baumannii can display a high ability to survive on inanimate surfaces. Therefore, cleaning and disinfection is an important part in the prevention of A. baumannii transmission. No-touch room decontamination is performed with increasing frequency to reach more standardization in hospital cleaning. In this study, we investigated the efficacy of an automated room decontamination using ozone (Sterisafe™ pro) against A. baumannii under complex room conditions. METHODS: A Carbapenemase-producing A. baumannii outbreak strain was analyzed with respect to its ability to survive on dry surfaces. The Sterisafe™ pro instrument was used in a patient room with an attached bathroom. The A. baumannii strain was dried on three different carriers (ceramic tiles, stainless steel, solid core furniture board) and placed at eight different positions in the rooms. A standard disinfection cycle (80 ppm ozone; 90 % RH; 60 minutes) was conducted in three independent experiments. RESULTS: The A. baumannii strain displayed a long-term survival on surfaces under dry conditions sufficient for further disinfection experiments. Interestingly, the mean reduction rates of A. baumannii dried on three surfaces displayed significant differences. Reduction rates greater than 5 log were reached on all stainless steel and ceramic carriers even under the complex room conditions using the standard disinfection cycle of the Sterisafe™ pro instrument. In contrast, on furniture board individual carriers displayed reduction rates of even less than 4 log. The mean reduction rate was still 5 log for A. baumannii on furniture board. CONCLUSION: A. baumannii dried on different surfaces display a differential susceptibility against automated ozone disinfection. However, the Sterisafe(TM) pro instrument displayed a sufficient reduction of A. baumannii for all tested surfaces even under complex room conditions. The individual behavior of A. baumannii on different materials indicate the necessity for the validation of automated room decontamination systems under varying conditions. DISCLOSURES: All authors: No reported disclosures.