Candida auris–Associated Candidemia, South Africa

To the Editor: We noted the report by Chowdhary et al. (1) and report Candida auris as a causative agent of candidemia in South Africa, with an estimated prevalence of 0.3% (N.P. Govender et al., unpub. data). First isolated in 2009, C. auris is an emerging species associated with clinical disease (2–6). We analyzed 4 isolates submitted to the National Institute for Communicable Diseases (Johannesburg, South Africa) from 4 patients with candidemia who had been admitted to different public- and private-sector hospitals from October 2012 through October 2013.

Identification of the isolates was undertaken by using ChromAgar Candida medium (Mast Diagnostics, Merseyside, UK), Vitek-2 YST (bioMérieux, Marcy ľEtoile, France), API 20C AUX (bioMérieux), and sequencing of internal transcribed spacer (ITS) and D1/D2 domains of the ribosomal RNA gene (7), followed by microbroth dilution susceptibility testing (8). All isolates were misidentified as C. haemulonii and Rhodotorula glutinis by Vitek-2 YST and API 20C AUX assays, respectively (Table).

Table. Identification and antifungal susceptibility results of 4 Candida auris isolates from 4 male patients with candidemia, South Africa, October 2012–October 2013*.

Isolate ID	Patient age, y	Hospital unit	Vitek-2 YST†	API 20C AUX†	DNA sequence analysis‡	MIC
						AMB	FLX	VRC	POS	ITC	5FC	CAS	MFG	AFG
208	85	High-care	C. haemulonii	Rhodotorula glutinis	C. auris	1	>256	0.5	0.03	0.12	0.12	0.25	0.06	0.25
209	60	Medical ICU	C. haemulonii	R. glutinis	C. auris	0.5	>256	1	0.06	0.12	0.12	0.12	0.06	0.12
224	73	Burn	C. haemulonii	R. glutinis	C. auris	1	>256	2	0.06	0.25	0.12	0.25	0.12	0.25
293	27	Trauma ICU	C. haemulonii	R. glutinis	C. auris	1	64	0.25	0.015	0.06	0.06	0.03	0.06	0.06

*AMB, amphotericin B; FLX, fluconazole; VRC, voriconazole; POS, posaconazole; ITC, itraconazole; 5FC, flucytosine; CAS, caspofungin; MFG, micafungin; AFG, anidulafungin.
†bioMérieux, Marcy ľEtoile, France.
‡Sequence data for the 4 isolates have been deposited in GenBank, accession nos. KJ1236762–KJ126765 and KJ126758–KJ126761 for the internal transcribed spacer and D1/D2 regions, respectively.

Similar to the findings of Chowdhary et al., all isolates assimilated N-acetyl-glucosamine (1). With the use of the CBS-KNAW database, pairwise sequence alignment of ITS region showed 99% sequence homology to Kuwait isolates, and alignment of D1/D2 domain showed 98% homology to the Kuwait/India isolates (9). In a neighbor-joining phylogenetic tree based on ITS sequences, South Africa isolates formed a cluster with India and Kuwait isolates (Technical Appendix Figure).

Fluconazole MICs were high for all isolates (Table). Isolates 209 and 224 showed reduced voriconazole susceptibility with MICs of 1 μg/mL and 2 μg/mL, respectively, which is above the epidemiologic cutoff value for 11 Candida species (10). Isolates were susceptible to amphotericin B and echinocandins at low MICs Clinical data were available for 1 patient (Technical Appendix Table). Two C. haemulonii isolates were identified during laboratory-based sentinel surveillance for candidemia in South Africa; the ITS region of one isolate was sequenced and the isolate identified as C. auris (N.P. Govender, pers. comm.). In this study, C. auris was misidentified by routinely used tests and was accurately identified by sequencing, in keeping with previous findings (1,3,4,6).

Technical Appendix

Phylogenetic relatedness of internal transcribed spacer region of the ribosomal RNA gene of Candida auris with closely related Candida species and clinical characteristics of a patient with candidemia caused by C. auris, South Africa.