Microsporum

Macroconidia_Microsporum_canis.JPG

Microsporum is a genus of fungi that causes dermatophytosis (ringworm) in humans and animals. It is one of the three genera of fungi that are collectively referred to as dermatophytes, the other two being Trichophyton and Epidermophyton. Microsporum species are characterized by their ability to infect keratinized tissues such as skin, hair, and nails.

Taxonomy and Classification

Microsporum belongs to the kingdom Fungi, the phylum Ascomycota, the class Eurotiomycetes, the order Onygenales, and the family Arthrodermataceae.

Species

There are several species within the genus Microsporum, including:

• Microsporum canis
• Microsporum gypseum
• Microsporum audouinii
• Microsporum nanum

Morphology

Microsporum species produce both macroconidia and microconidia. The macroconidia are large, spindle-shaped, and multi-celled, while the microconidia are small, single-celled, and spherical or pyriform. These fungi are typically identified by their characteristic macroconidia under a microscope.

Pathogenicity

Microsporum species are known to cause tinea capitis (scalp ringworm), tinea corporis (body ringworm), and tinea pedis (athlete's foot). The infection is typically transmitted through direct contact with infected individuals or animals, or through contact with contaminated objects such as combs, brushes, and clothing.

Diagnosis

Diagnosis of Microsporum infections is usually made through clinical examination and confirmed by laboratory tests. These tests may include:

• Wood's lamp examination, where infected hairs fluoresce under ultraviolet light.
• Direct microscopic examination of skin scrapings or hair samples treated with potassium hydroxide (KOH).
• Fungal culture on Sabouraud dextrose agar.

Treatment

Treatment of Microsporum infections typically involves the use of topical or oral antifungal medications. Commonly used antifungal agents include:

• Terbinafine
• Itraconazole
• Griseofulvin
• Ketoconazole

Prevention

Preventive measures include maintaining good personal hygiene, avoiding sharing personal items, and treating infected pets. In some cases, prophylactic antifungal treatment may be recommended for individuals at high risk of infection.

See Also

• Dermatophyte
• Trichophyton
• Epidermophyton
• Tinea