Related Experiment Videos
The first isolation of Hortaea werneckii from a household guinea pig
Shahana Sharmin1, Kumiko Haritani, Reiko Tanaka
1Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan.
Abstract:
Hortaea werneckii, a black yeast and the causative agent of tinea nigra (a superficial type of dermatomycosis), is a human pathogen and is also found in the environment. It is not highly pathogenic but in the last fifteen to twenty years has been isolated from various human and environmental sources in Japan. As far as we know, there has been no report on the isolation of H. werneckii from animals. Recently, we found a case of a guinea pig with dark superficial lesions on the palm and dorsal areas. Cultural and morphological studies of scrapings from the lesion showed that the causative agent was a black yeast, which was identified as H. werneckii by morphological study and molecular biological screening. D1/D2 region of the 26S large subunit rDNA gene of this isolate was identical to those of 11 other H. werneckii isolates used as reference strains in this study. This is the first case recorded of tinea nigra caused by H. werneckii in a guinea pig.
Insights
This study reports the first documented case of tinea nigra in a guinea pig, caused by the black yeast Hortaea werneckii. This finding expands the known host range for this superficial fungal infection.
Area of Science:
- Medical Mycology
- Veterinary Dermatology
- Fungal Pathogenesis
Background:
- Hortaea werneckii is an environmental black yeast and the causative agent of tinea nigra, a superficial fungal infection in humans.
- While H. werneckii is found in various environmental and human sources, its isolation from animals has not been previously reported.
- Recent isolations of H. werneckii in Japan highlight its presence in diverse ecological niches.
Observation:
- A guinea pig presented with superficial, dark lesions on its palm and dorsal areas.
- Diagnostic procedures included cultural and morphological examination of scrapings from the affected skin.
- The observed lesions were consistent with a superficial dermatomycosis.
Findings:
- Microscopic and cultural analyses identified the causative agent as a black yeast.
- Morphological studies and molecular screening confirmed the yeast as Hortaea werneckii.
- Genetic analysis of the D1/D2 region of the 26S large subunit rDNA gene showed identity with known H. werneckii reference strains.
- This marks the first recorded instance of tinea nigra in a guinea pig attributed to H. werneckii.
Implications:
- This case expands the known host spectrum of Hortaea werneckii, indicating it can infect non-human mammals.
- The findings suggest a potential role for domestic animals, like guinea pigs, in the transmission or reservoir of H. werneckii.
- Further research is warranted to understand the epidemiology and transmission dynamics of H. werneckii in animal populations and its zoonotic potential.