Objective: Invasive candidiasis (IC), a life-threatening fungal infection prevalent among hospitalized patients, has highly variable regional epidemiology. We conducted a multicenter surveillance study to investigate recent trends in species distribution and antifungal susceptibility patterns among IC-associated Candida  spp. in Beijing, China, from 2016 to 2017.
Materials and Methods: A total of 1496 non-duplicate Candida  isolates, recovered from blood and other sterile body fluids of IC patients, were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry combined with ribosomal DNA internal transcribed spacer (ITS) region sequencing. Broth microdilution-based susceptibility testing using six antifungal agents was also conducted.
Results: Candida albicans  was the most frequently isolated species (49.9%), followed by Candida tropicalis  (15.5%), Candida glabrata  (14.7%) and Candida parapsilosis  (14.2%). No significant differences in species distribution were observed when compared with a 2012– 2013 dataset. Overall, the rates of susceptibility to fluconazole and voriconazole were high among C. albicans  (98% and 97.2%, respectively) and C. parapsilosis  species complex (91.1% and 92%, respectively) isolates but low among C. tropicalis  (81.5% and 81.1%, respectively) isolates. In addition, the rate of azole resistance among C. tropicalis  isolates increased significantly (1.8-fold, P < 0.05) compared with that observed in 2012– 2013, while micafungin resistance rates were < 5% for all tested Candida  species.
Conclusion: Our results suggest that species distribution has remained stable among IC-associated Candida  isolates in Beijing. Resistance to micafungin was rare, but increased azole resistance among C. tropicalis  isolates was noted. Our study provides information on local epidemiology that will be important for the selection of empirical antifungal agents and contributes to global assessments of antifungal resistance.
Keywords: invasive fungal infections, Candida , species distribution, antifungal resistance, surveillance, Beijing