Candida haemulonii was originally described from a
strain obtained from the gut of a blue-striped grunt
(Haemulon sciurus) in 1962 (17). Lavarde et al. (6)
reported the first clinical isolation of this microorganism
from the blood of a patient in 1984. Subsequently, this
fungus has been isolated from the nails and toes of
patients in the United States (3). Clinical isolates iden-
tified as C. haemulonii can be divided into types I and II
based on their isoenzyme and protein profiles, and this
division was supported by a DNA-DNA hybridization
study by Lehmann et al. (7). Type I includes the type
strain of this microorganism. Although the type II
strain should be treated as a new species, the new taxon
remains to be established. At present, the name “C.
haemulonii types I and II” is used in the field of yeast
taxonomy. During a taxonomic investigation of clinical
isolates from Thai patients, we found a strain that was
resistant to amphotericin B and azoles in a patient’s
blood. The clinical isolate was phylogenetically similar
to C. haemulonii, which is also resistant to ampho-
tericin B. In this paper, we propose a new species, C.
pseudohaemulonii, for the isolate.
Strain DMST 17134 was isolated from the blood of a
Thai patient at Mae Sot Hospital. The Candida haemu-
lonii type I and II strains were purchased from the Cen-
traalbureau voor Schimmelcultures and were studied for
comparison (Table 1).
Fungal DNA was extracted using the method of
Makimura et al. (8). The internal transcribed spacer
(ITS) and D1/D2 regions of the 26S rDNA of the rRNA
gene were amplified using the primer pairs pITS-F (5'
GTCGTAACAAGGTTAACCTGCGG) and pITS-R (5'
TCCTCCGCTTATTGATATGC) (13) and NL1 (5'
GCATATCAATAAGCGGAGGAAAAG) and NL4 (5'
GGTCCGTGTTTCAAGACGG) (5), respectively. The
PCR products were sequenced using the same four
primers. The sequences were aligned using Clustal W
software (15). For the neighbor-joining analysis (12),
the distances between sequences were calculated using
Kimura’s two-parameter model (4). A bootstrap analy-
sis was conducted with 100 replications (1). Figure 1
shows the tree constructed using the D1/D2 26S rDNA
Candida pseudohaemulonii Sp. Nov.,
an Amphotericin B- and Azole-Resistant Yeast
Species, Isolated from the Blood of a Patient from
Takashi Sugita*, 1, Masako Takashima2, Natteewan Poonwan3, and Nanthawan Mekha3
1Department of Microbiology, Meiji Pharmaceutical University, Kiyose, Tokyo 204–8588, Japan, 2Microbe Division, Japan
Collection of Microorganisms, RIKEN BioResource Center, Wako, Saitama 351–0198, Japan, and 3Mycology Section,
National Institute of Health, Department of Medical Sciences, Nonthaburi, 11000 Thailand
Received February 28, 2006; in revised form, March 9, 2006. Accepted March 13, 2006
Abstract: Candida haemulonii (types I and II) is rarely isolated from clinical specimens. We isolated a
strain that is phylogenetically close to C. haemulonii from the blood of a Thai patient, and named it C.
pseudohaemulonii sp. nov. (CBS 10099T?JCM 12453T?DMST 17134T). The new species and C. haemu-
lonii types I and II were resistant to amphotericin B and azole agents but were susceptible to a 1,3-?-D-glu-
can synthetase inhibitor, micafungin, and 5-flucytosine. The species were easily distinguished using an
ID32 yeast identification kit. The taxonomic description of C. pseudohaemulonii sp. nov. is presented.
Key words: Candida haemulonii, New species, Amphotericin B, Azole
Microbiol. Immunol., 50(6), 469–473, 2006
Abbreviations: CBS, Centraalbureau voor Schimmelcultures,
Utrecht, The Netherlands; DDBJ, DNA Data Bank of Japan;
DMST, National Institute of Health, Department of Medical Sci-
ences, Nonthaburi, Thailand; ITS, internal transcribed spacer;
JCM, Japan Collection of Microorganisms, RIKEN, Japan;
NRRL, Agricultural Research Service Culture Collection,
National Center for Agricultural Utilization Research, Peoria, Ill.,
*Address correspondence to Dr. Takashi Sugita, Department
of Microbiology, Meiji Pharmaceutical University, 2–522–1
Noshio, Kiyose, Tokyo 204–8588, Japan. Fax: ?81–424–95–8762.