NP-006 Prevention measures against<i>candida auris</i>diffusion in nocosomial settings

<h3>Background and Importance </h3> <i>Candida auris (C. </i><i>auris)</i> is a multiresistant yeast, which can colonise immunocompromised patients, causing invasive infections. Assuming its natural propension into developing biofilm, it can rapidly adapt to inert surfaces in hospital environments. <h3>Aim and Objectives</h3> Our objective is to identify proper prevention measures to be applied in nosocomial settings in order to counteract its diffusion, finding the most efficient disinfectants and creating guidelines to contrast <i>C. auris</i> related infective emergencies. <h3>Materials and Methods</h3> The sensitivity of the following disinfectants was evaluated in vitro on clinical and environmental strains of<i> C. auris</i>: 1) quaternary ammonium in ethyl alcohol; 2) polyesanide; 3) sodium hypochlorite, sodium hydroxide, sodium carbonate and sodium chloride; 4) phenols. Disinfectants have been used following manufacturer instructions. Molecules efficacy was tested by agar well diffusion method. In particular, 90 mm diameter dish containing agarose soil with Sabouraud were contaminated with<i> C. auris</i> strains isolated from a colonised patient, the environment and American Type Culture Collection (ATCC) standard strain. Then, on the seeded soils, 100 μl of each disinfectant was added to 10 mm diameter discs. After incubation at 37°C for 24/48 hours, the diameters of inhibition growth zones were measured. A growth zone of &gt;14 mm diameter was interpreted as effective. <h3>Results</h3> All the tested disinfectants were efficient, with a significant growth decrease of <i>C. auris</i> with the following results: 1) quaternary ammonium: sensitive - inhibition diameter of 26 mm; 2) polyhexanide: sensitive - inhibition diameter of 17 mm; 3) sodium hypochlorite, sodium hydroxide, sodium carbonate and sodium chloride: sensitive – inhibition diameter of 50 mm; 4) phenols: sensitive – inhibition diameter of 26 mm. No significant difference was found in the sensibility between the clinical strain and the environmental one. <h3>Conclusions and Relevance</h3> The highest inhibition was achieved with the hypochlorite disinfectant, followed by quaternary ammonium salt. These results showed the availability of many effective molecules on <i>C. auris</i> strains, simplifying the periodic disinfectant replacement to prevent resistance from genetically predisposed strains. <h3>References and/or Acknowledgements</h3> Preda M, Chivu RD, Ditu LM, Popescu O, Manolescu LSC. Pathogenesis, Prophylaxis, and Treatment of Candida auris. <i>Biomedicines</i> 2024;<b>12</b>(3):561. Kriegl L, Egger M, Boyer J, Hoenigl M, Krause R. New treatment options for critically important WHO fungal priority pathogens. <i>Clin Microbiol</i> Infect 2024. <h3>Conflict of Interest</h3> No conflict of interest.