The genus Alternaria is found worldwide and in a variety of habitats. Alternaria species are ubiquitous agents of decay, commonly recovered from plant litter, sewage, paper, textiles, food and building materials. Some species may also act as plant pathogens. Alternaria is often recovered from water damaged buildings. Alternaria spores are dispersed by air currents and are frequently isolated from outdoor air.

Health Effects
Alternaria is a common allergen. Over 70 secondary metabolites of varying toxicity have been found to be produced by species of Alternaria; as such, the occurrence of Alternaria mycotoxins in foodstuffs is becoming an increasing concern. Although Alternaria is not generally considered pathogenic to humans, cases of opportunistic infections in immuno-compromised patients (i.e. underlying autoimmune diseases such as AIDS or recent recipients of transplants) are becoming more common.

Aspergillus is a cosmopolitan fungus with a worldwide distribution. Aspergillus is often isolated from soil and plant materials, particularly in tropical and sub-tropical regions. Aspergillus spores are generally air dispersed.

Health Effects
A number of Aspergillus species have been recognized as agents in human mycoses. The most common species implicated are A. flavus and A. fumigatus. Aspergillus species are common allergenic agents and can also cause invasive disease.

Aspergillus flavus has a world-wide distribution and is mainly isolated from tropical and subtropical areas. A. flavus can be isolated from soil but more attention has been focused on its’ isolation from agricultural crops and products (ex. peanuts). In indoor environments A. flavus can be isolated from food, wood and wood products and other building materials.

Health Effects
Aspergillus flavus is known as human, insect and animal pathogen and is a common agent of mycotic sinusitis. A. flavus is a main agent of human allergic bronchial aspergillosis with symptoms like fever, vomiting, coma, and convulsions. Also can cause infection of external ear.

Aspergillus flavus can cause aspergillosis, which is most commonly an infection of the lungs and sinuses that grows throughout the mucus. Several symptoms are associated with the infection including chest pain, cough, uneasy breath control, fever, and sweating. In immunocompromised patients (ex. cancer and AIDS) aspergillosis may result in fatality. In these cases the fungus is able to grow from its origin within the lungs to blood vessels and eventually to other organs through the blood.

Produces aflatoxin-B1 as a very potent carcinogen, teratogenic and cause aflatoxicosis. Ingestion of this toxin can cause liver and lung cancer. Traumatic cases are associated with underlying diseases like diabetes.

Aspergillus Fumigatus is ubiquitous, reported from a wide range of substrates like soils, plants, seeds, sludge, wood chips, compost, cotton, and excreta of birds like penguins. Aspergillus Fumigatus is abundant on rotten plant material at higher temperatures and in air during biological waste treatment.

Health Effects
Aspergillus Fumigatus is a human and animal (pets like dogs and cats) pathogen. Some of the allergies that it may cause are the following:

• Asthma and Rhinitis and farmers lung (allergic alveolitis)
• Hypersensitive pneumonitis
• Most common cause of invasive disseminated Aspergillosis
• Frequent agent of allergic fungal sinusitis which may lead to fungal balls or become invasive and may cause cranial life - threatening complications

Aspergillus Fumigatus may also cause infections like keratitis and organ infection only to the patients with compromised immune response. Such infection can affect the skin, the eyes, the lung, or other organs or systems. It may also cause nosocomial infection in immunocompromised patients due to hygiene problems or due to construction work. Some toxins associated with Aspergillus Fumigatus are Fumitotoxin, Chanoclavine, Tryptoquivalins, Fumitrimorgins, Verrucologen, Ergot alkaloids, and Fumigatoxins.

This is one of several genera known as "black yeasts", a group of fungi characterized by dark, pasty colonies. In early stages of growth, colonies of Aureobasidium are fast growing, smooth, flat, and covered with slimy masses of conidia, cream or pink, later becoming brown or black and velvety at maturity.

Health Effects
Aureobasidium spores can act as allergens in sensitive individuals. Some species are weakly pathogenic and can cause infections in the skin, nails, and eyes; however, infections caused by Aureobasidium remain limited and uncommon.

Health Effects
Beauveria is a very common insect pathogen but a very rare human pathogen. It has been reported to be associated with keratitis and a case of pneumonia in an immunocompromised patient.