Candida haemuloniiand Closely Related Species at 5 University Hospitals in Korea: Identification, Antifungal Susceptibility, and Clinical Features

Abstract

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.

Itraconazole-resistant Candida auris with phospholipase, proteinase and hemolysin activity from a case of vulvovaginitis

“…There have been a handful of reports on C. auris as a pathogen causing fungemia [9,10] but in this case C. auris was found as the causative agent for vulvovaginitis. The increasing isolation of C. auris from various clinical specimens clearly indicates its ability to colonise, invade and cause disease with varying severity.…”

Identification and Antifungal Susceptibility Profiles of Candida haemulonii Species Complex Clinical Isolates from a Multicenter Study in China

“…haemulonii complex often exhibits antifungal resistance, with clinical failure associated with in vitro resistance to amphotericin B and reduced susceptibility to azoles (6,7,9,10,(13)(14)(15). Moreover, C. haemulonii isolates with resistance to echinocandins have been reported (11).…”

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“…Candida auris was first identified in a Japanese patient from external ear in 2009 by sequencing of nuclear rRNA 21 . Fifteen isolates of this species were reported from otitis media patients in South Korea in the same year but fungemia was rare in this series 22 . Isolates from our study were resistant to azoles and one of these was resistant to caspofungin also.…”