Candida auris: A pathogen difficult to identify, treat, and eradicate and its characteristics in Japanese strains

Candida auris is a multidrug-resistant and emergent pathogen that has caused healthcare-associated infection outbreaks. Recently, C. auris has spread worldwide; nevertheless, it was unexpectedly rare before 2009. Based on the molecular epidemiological analysis, C. auris may independently emerge at specific areas at first and recently may be transmitted to other continents. As C. auris cannot be detected using conventional methods, internally transcribed spacers, D1/D2 regions of the 26S rDNA sequencing, and/or matrix-assisted laser desorption ionization time-of-flight mass spectrometry method can be selected as comparatively accessible choices. Thus, detection of C. auris using the conventional method might be underestimated. In Japan, all C. auris strains were isolated from ear specimen and not from invasive mycoses. Japan strains were classified as an East Asian clade under a single clone. Although colonization, virulence, and infection pattern are almost the same as with other Candida species, its antifungal resistance is different. Fluconazole resistance is notably common, but resistance to all three classes of antifungals (azole, polyene, and echinocandin) rarely exists. Once C. auris is detected, screening, emphasis on hand hygiene adherence, use of single-patient room isolation, contact precaution, surveillance, and eradication from the environment and patients are appropriately required for infection control.