Affiliation:
1. Centraalbureau voor Schimmelcultures, P.O. Box 85167, NL-3508 AD Utrecht
2. Institute for Biodiversity and Ecosystem Dynamics, Amsterdam, The Netherlands
3. Department of Dermatology and Venereology, Union Hospital, Tongji Medical College, Huazhong Science and Technology University, Jiefang Dadao 1277, Wuhan, Hubei, China
4. Fungus Testing Laboratory, University of Texas Health Science Center, San Antonio, Texas
5. Audie L. Murphy Memorial Veterans' Hospital, South Texas Veterans Health Care System, San Antonio, Texas
Abstract
ABSTRACT
Numerous members of the genus
Exophiala
are potential agents of human and animal mycoses. The majority of these infections are cutaneous and superficial, but also fatal systemic infections are known. We re-identified 188 clinical isolates from the United States, which had a preliminary morphological identification of
Exophiala
species, by sequencing internal transcribed spacer (ITS) region of the rRNA. Molecular identifications of the strains were as follows, in order of frequency: 55
E. dermatitidis
(29.3%), 37
E. xenobiotica
(19.7%), 35
E. oligosperma
(18.6%), 13
E. lecanii-corni
(6.9%), 12
E. phaeomuriformis
(6.4%), 7
E. jeanselmei
(3.7%), 7
E. bergeri
(3.7%), 6
E. mesophila
(3.2%), 5
E. spinifera
(2.7%), 3
Exophiala
sp. 1 (1.6%), 3
E. attenuata
(1.6%), 3
Phialophora europaea
(1.3%), 1
E. heteromorpha
(0.5%), and 1
Exophiala
sp. 2 (0.5%) strains.
Exophiala
strains were repeatedly isolated from deep infections (39.9%) involving lung, pleural fluid, sputum, digestive organs (stomach, intestines, bile), heart, brain, spleen, bone marrow, blood, dialysis fluid, lymph node, joint, breast, middle ear, throat, and intraocular tissues. About 38.3% of the
Exophiala
spp. strains were agents of cutaneous infections including skin, mucous membranes, nail, and corneal epithelium lesions. The other strains caused superficial infections (0.5%, including hair) or subcutaneous infection (12.0%, including paranasal sinusitis, mycetoma, and subcutaneous cyst). The systemic infections were preponderantly caused by
E. dermatitidis
,
E. oligosperma
,
E. phaeomuriformis
,
E. xenobiotica
, and
E. lecanii-corni
. Strains of
E. bergeri
,
E. spinifera
,
E. jeanselmei
,
E. mesophila
, and
E. attenuata
mainly induced cutaneous and subcutaneous infections. Since relatively few unknown ITS motifs were encountered, we suppose that the list of opportunistic
Exophiala
species in temperate climates is nearing completion, but a number of species still have to be described.
Publisher
American Society for Microbiology