Species/common name:

Alternaria alternate (older name: Alternaria tenuis)

Teleomorph: None

Natural habitat

It can be found in soil, air and it has also been described on normal human and animal skin and conjunctiva.

Geography

Worldwide distribution

Frequency

It is frequently associated with allergic respiratory disease. It is an infrequent case of localized and disseminated infections.

Diseases:

Alternaria alternata is able to produce the following diseases

1.     Allergic respiratory disease, including thunderstorm asthma and SAFS. (see video)

2.     Allergic fungal rhinosinusitis

3.     Opportunistic infections in immunocompromised hosts, including in skin, paranasal sinuses and lungs.

4.     Keratitis, peritonitis, osteomyelitis, sinusitis, endophthalmitis, and cutaneous and subcutaneous infections associated with a previous trauma.

Culture peculiarities

Fast growing colonies, grey to black and powderly to floccose. Microscopically, conidiophores arise from septate hyphae. Multicelled conidia are produced sympodially in chains (usually composed of more than 5 conidia). Conidia are obclavate, pyriform to ovoid or ellipsoidal up to 50 mm long and 3-12 mm wide. Brown pigmented with smooth to verrucose surface.

Antifungal resistance (intrinsic and acquired)

This species is resistant to fluconazole. Resistance to itraconazole and voriconazole have been described and some strains have shown in vitro resistance to amphotericin B.

Biosafety level 2

This fungal species may be managed in a laboratory with safety containment level 2.