Onygenaceae

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Onygenaceae
Kingdom:	Fungi
Phylum:
Class:	Eurotiomycetes
Order:	Onygenales
Family:	Onygenaceae

Onygenaceae is a family of fungi within the order Onygenales, class Eurotiomycetes, and division Ascomycota. This family is notable for including several genera that are pathogenic to humans and animals, causing diseases such as dermatophytosis and histoplasmosis.

Description

Members of the Onygenaceae family are primarily saprophytic, meaning they feed on dead or decaying organic matter. However, some species are keratinophilic, which allows them to degrade keratin, a protein found in skin, hair, and nails. This ability is particularly significant in the context of pathogenic species that infect humans and animals.

The fungi in this family typically produce ascomata, which are fruiting bodies that contain the asci and ascospores. The ascomata can vary in form, from simple structures to more complex, enclosed forms. The asci are usually cylindrical and contain eight ascospores.

Pathogenic Genera

Several genera within the Onygenaceae family are of medical importance due to their pathogenic nature:

• Trichophyton: This genus includes species that cause dermatophytosis, commonly known as ringworm, affecting skin, hair, and nails.
• Microsporum: Another genus responsible for dermatophytosis, particularly in children.
• Histoplasma: Known for causing histoplasmosis, a respiratory disease that can become systemic, especially in immunocompromised individuals.
• Coccidioides: Causes coccidioidomycosis, also known as Valley fever, which can lead to severe respiratory illness.

Ecology

Onygenaceae fungi are found worldwide, with some species adapted to specific ecological niches. They are commonly isolated from soil, decaying organic matter, and animal remains. The keratinophilic species are often found in environments rich in keratinous material, such as animal shelters, farms, and areas with high human activity.

Clinical Significance

The pathogenic species within Onygenaceae are significant in clinical mycology. Dermatophytes like Trichophyton and Microsporum are responsible for superficial infections, while systemic infections caused by Histoplasma and Coccidioides can be life-threatening. Diagnosis typically involves culture, microscopy, and molecular techniques to identify the specific fungal species.

Treatment

Treatment of infections caused by Onygenaceae fungi depends on the specific pathogen and the severity of the infection. Superficial infections are often treated with topical antifungal agents, while systemic infections may require oral or intravenous antifungal medications such as itraconazole, fluconazole, or amphotericin B.

Also see

• Dermatophyte
• Ascomycota
• Fungal infection
• Histoplasmosis
• Coccidioidomycosis