The Epidemiology and Infection Control of Candida Auris in Shanghai

Background Candida auris is a globally emerging multidrug-resistant fungus. Its dissemination is driven by patient movement and asymptomatic carriers. However, molecular epidemiological studies linking imported cases to local strains in large metropolitan areas remain limited. Objectives To analyse the molecular epidemiology and resistance mechanisms of 33 clinical isolates in Shanghai and propose an integrated infection control strategy tailored to metropolitan healthcare settings. Methods Isolates from 19 patients were identified via MALDI-TOF MS and sequencing. Antifungal susceptibility and biofilm formation were assessed. Environmental contamination was evaluated using PCR. Whole-genome sequencing (WGS) was employed to identify resistance mutations and perform phylogenetic analysis. Results All 33 isolates were fluconazole-resistant. Resistance to amphotericin B and echinocandins was observed in 9 and 4 isolates, respectively. All echinocandin-resistant strains harboured the Fks1-S639F mutation. Phylogenetic analysis revealed that Clade III (South African clade) was the dominant lineage. Colonisation was concentrated in the urinary tract and inguinal regions, while bedside tables were identified as key environmental reservoirs. All strains exhibited strong biofilm-forming capacity. Conclusions ICU patients serve as primary reservoirs, with transmission driven by interregional movement. The distinct colonisation patterns and environmental hotspots provide specific targets for screening. Integrating PCR-based environmental monitoring with culture methods constitutes an effective strategy. These findings underscore the need for a standardised protocol integrating molecular diagnostics to optimise infection control in urban hospitals.