Acremonium

Acremonium' is a genus of fungi that encompasses a wide range of species, previously classified under the genus Cephalosporium. Acremonium species are characterized by their filamentous growth, producing slender, hyaline (transparent), and septate hyphae. These fungi are cosmopolitan, found in soil, plant debris, and indoor environments, contributing to the decomposition of organic matter. However, some species have been identified as opportunistic pathogens in humans, causing infections known as hyalohyphomycosis, a term referring to infections by fungi with hyaline hyphae.

Characteristics

Acremonium species produce conidiophores that are simple or sparingly branched, bearing at their tips slim phialides from which conidia are produced. The conidia are usually one-celled, hyaline, and accumulate in slimy droplets at the tips of the phialides. Morphologically, the identification of Acremonium species can be challenging due to their similarity with other filamentous fungi.

Habitat and Ecology

Acremonium fungi are ubiquitous, thriving in a variety of environments including soil, plant matter, and indoor environments where moisture is present. They play a significant role in the ecosystem by decomposing organic material. However, their presence in indoor environments, such as damp or water-damaged buildings, can contribute to poor indoor air quality and pose health risks to individuals with compromised immune systems.

Pathogenicity

While most Acremonium species are harmless saprophytes, a few have been implicated in human and animal diseases. In humans, Acremonium species can cause a range of infections, including keratitis (infection of the cornea), onychomycosis (fungal nail infections), and more severe systemic infections in immunocompromised individuals. These infections are often difficult to treat due to the resistance of Acremonium species to many conventional antifungal drugs.

Diagnosis and Treatment

Diagnosis of Acremonium infections involves clinical assessment, imaging, and laboratory tests, including fungal culture and histopathological examination. Treatment typically involves the use of systemic antifungal medications, but the efficacy varies depending on the species of Acremonium and the site of infection. Surgical intervention may be necessary in cases of localized infections, such as keratitis or onychomycosis.

Prevention

Preventing Acremonium infections involves controlling moisture and humidity in indoor environments to inhibit the growth of mold and fungi. Regular maintenance and prompt repair of water damage in buildings can significantly reduce the risk of exposure to Acremonium and other opportunistic pathogens.

See Also

• Mycology
• Fungal infection
• Immunocompromised host

External Links

• CDC - Fungal Diseases
• WHO - Mycetoma