Candida haemulonii and closely related species at 5 university hospitals in Korea: identification, antifungal susceptibility, and clinical features.
Background. Candida haemulonii, a yeast species that often exhibits antifungal resistance, rarely causes human infection. During 2004-2006, unusual yeast isolates with phenotypic similarity to C. haemulonii were recovered from 23 patients (8 patients with fungemia and 15 patients with chronic otitis media) in 5 hospitals in Korea. Methods. Isolates were characterized using D1/D2 domain and ITS gene sequencing, and the susceptibility of the isolates to 6 antifungal agents was tested in vitro. Results. Gene sequencing of the blood isolates confirmed C. haemulonii group I (in 1 patient) and Candida pseudohaemulonii (in 7 patients), whereas all isolates recovered from the ear were a novel species of which C. haemulonii is its closest relative. The minimum inhibitory concentration (MIC) ranges of amphotericin B, fluconazole, itraconazole, and voriconazole for all isolates were 0.5-32 microg/mL (MIC(50), 1 microg/mL), 2-128 microg/mL (MIC(50), 4 microg/mL), 0.125-4 microg/mL (MIC(50), 0.25 microg/mL), and 0.03-2 microg/mL (MIC(50), 0.06 microg/mL), respectively. All isolates were susceptible to caspofungin (MIC, 0.125-0.25 microg/mL) and micafungin (MIC, 0.03-0.06 microg/mL). All cases of fungemia occurred in patients with severe underlying diseases who had central venous catheters. Three patients developed breakthrough fungemia while receiving antifungal therapy, and amphotericin B therapeutic failure, which was associated with a high MIC of amphotericin B (32 microg/mL), was observed in 2 patients. Conclusions. Candida species that are closely related to C. haemulonii are emerging sources of infection in Korea. These species show variable patterns of susceptibility to amphotericin B and azole antifungal agents.
Kim
Mi-Na
MN
Department of Laboratory Medicine, Ulsan University College of Medicine, Seoul, Republic of Korea.
Shin
Jong Hee
JH
Sung
Heungsup
H
Lee
Kyungwon
K
Kim
Eui-Chong
EC
Ryoo
Namhee
N
Lee
Jin-Sol
JS
Jung
Sook-In
SI
Park
Kyung Hwa
KH
Kee
Seung Jung
SJ
Kim
Soo Hyun
SH
Shin
Myung Geun
MG
Suh
Soon Pal
SP
Ryang
Dong Wook
DW
D000368:Aged; D000935:Antifungal Agents / Q000494:pharmacology*; D001769:Blood / Q000382:microbiology; D002175:Candida / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification; D002177:Candidiasis / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology / Q000503:physiopathology; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007223:Infant; D007723:Korea / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
D000935:Antifungal Agents; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer