Analysis of a Candida auris Outbreak Provides New Insights into an Emerging Pathogen

Abstract

Candida auris is an emerging human fungal pathogen that is being increasingly linked to outbreaks. It is concerning to health care workers because of its high mortality rate, due primarily to its antifungal resistance. Among the tools being developed to study this yeast are large cohorts of regional isolates, which can be useful for studying epidemiology, antifungal susceptibility patterns, and diagnostic methods. In this issue of the Journal of Clinical Microbiology, Y. Zhu, B. O’Brien, L. Leach, A. Clarke, et al. (J Clin Microbiol 58:e01503-19, 2020, https://doi.org/10.1128/JCM.01503-19) describe the laboratory findings of a collection of isolates from a large outbreak of C. auris obtained from numerous health care facilities in the New York area. Real-time PCR was used as a screening tool with great accuracy, while internal transcribed spacer (ITS) and D1/D2 sequencing were successfully employed for isolate clade assignment. South Asia clade I was identified as the major genotype, while South American clade IV was a minor genotype. Surveillance isolates from patients confirmed axilla/groin and nare colonization; however, results of quantitative analysis of fungal burdens showed that when the nares are colonized, burdens are significantly higher than for axilla/groin colonization. Antifungal susceptibility testing was in agreement with past studies. High levels of fluconazole resistance were detected, while few isolates were resistant to echinocandins. Resistance to multiple antifungals was frequent, and three isolates were recovered that appeared to be pan-resistant. This type of study is yet another useful tool for investigating C. auris, which is becoming an increasingly important human fungal pathogen that should be monitored very closely.

Optimizing a real-time PCR assay for rapid detection of Candida auris in nasal and axillary/groin samples

“…Rapidly identifying patients with C. auris colonization in healthcare facilities is critical for implementation of proper infection-control measures to contain the spread. Swabs of nares, axilla and groin were identified as the high-yield body sites for identifying C. auris-colonized patients [6]. A realtime PCR assay testing for C. auris in patient surveillance samples has been reported.…”

“…Investigation of C. auris hospital outbreaks revealed that patients infected with C. auris harboured the organism at multiple body sites, including nares, groin, axilla and rectum 1 to 3 months after initial detection of C. auris, and persistence of the organism in the patient room could be detected 3 months after patient discharge [5]. Nares, axilla and groin were identified as high-yield body sites for identifying colonized patients [6]. Assays for C. auris surveillance need to work with a common sample transportation medium for patient and environmental sampling.…”

Ibrexafungerp: A Novel Oral Triterpenoid Antifungal in Development for the Treatment of Candida auris Infections

“…Candida auris is an emerging fungal pathogen reported on all continents except Antarctica, in at least 39 countries worldwide [ 1 ], as well as in 20 states of the United States [ 2 , 3 , 4 , 5 ]. Five distinct clades of C. auris were identified with well-defined geographic distributions (South America, Africa, South Asia, East Asia, and West Asia), as well as antifungal resistance patterns and mechanisms that are both distinct and unique [ 1 , 6 , 7 , 8 ]. Infections due to C. auris are most often nosocomial, with easy transmission from patient-to-environment and environment-to-patient [ 6 , 9 ].…”

“…Timely and accurate diagnosis of invasive candidiasis are important for early initiation of antifungal therapy, while species identification is critical to ensure implementation of infection control measures [ 1 , 6 , 10 , 11 ]. Acceptable standard diagnostic methods for C. auris identification include matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) and VITEK2™ with the appropriate updated databases and DNA sequencing [ 7 , 12 ].…”

Echinocandins as Biotechnological Tools for Treating Candida auris Infections

“…C. auris is a multidrug-resistant pathogen that has been identified in 39 countries and has spread across five continents, with a mortality rate of ~78% [ 3 ]. Furthermore, risk factors that aggravate C. auris infections include conditions such as diabetes mellitus, cardiovascular surgical interventions and gastrointestinal pathologies, hematological malignancies and even corticosteroid therapy [ 4 ].…”