Journal of mycology and infection

Images in Mycology

Macroscopic Findings of Talaromyces scorteus

Jeongsoo Lee,Nuri Na,Joonsoo Park
10.17966/JMI.2019.24.3.89 Epub 2019 October 02

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Abstract

Keywords

Laboratory contaminants Talaromyces scorteus

Talaromyces scorteus is a species of the genus Talaromyces, family Trichocomaceae, order Eurotiales, class Eurotiomycetes, division Ascomycota¹. The genus Talaromyces was described by Benjamin in 1955 as a sexual state of Penicillium that produces soft walled ascomata covered with interwoven hyphae³. It is a mold in the environment and a yeast in the tissues at 37℃². The yeast divides by septation and not budding in contrast to most other dimorphic fungi³. It is endemic in rural areas in most South Eastern Asian countries¹.

On Saboraud Dextrose Agar after incubation at 25℃ for 2 weeks, T. scorteus colonies mature rapidly and are flat, white colored, and texture ranges from wooly to cottony. The colonies become "Mugwort" color to dark green colored with age (Figure 1A). The color of the colony is white initially but darkens to dark green with maturity on the reverse side (Figure 1B). There was no exudates and soluble pigment.

This specimen came from patient who is diagnosed malassezia folliculitis. To identify the exact strain of fungus, sequencing was performed with internal transcribed spacer region isolated from the colonies. This sequence was 100% identical with T. scorteus. Basic Local Alignment Search Tool (BLAST) search showed that the most similar strain was T. scorteus.

Talaromyces species are commonly considered nonpathogenic laboratory contaminants that are widely found in nature¹. If these fungi were shown on patient's specimen, several cultures and exact identification should be done.

Figure 1. (A) On Saboraud Dextrose Agar after incubation at 25℃ for 2 weeks, T. scorteus colonies mature rapidly and are flat, white colored, and texture ranges from wooly to cottony. (B) The color of the colony is white initially but darkens to dark green with maturity on the reverse side.

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