Phonetic: Pen-uh-sill’-ee-um

A large number of organisms belong to this genus, and identification to species is difficult. Often found in aerosol samples, it is common in soil, food, cellulose, paint, grains, and compost piles. In the indoor environment it is in carpet, wallpaper, and in interior fiberglass duct insulation. Although this fungus causes fewer allergies than other molds, Penicillium is reported to be a type I & III allergen. It may cause hypersensitivity pneumonitis and allergic alveolitis in susceptible individuals. It can cause other infections such as keratitis, penicilliosis, and otomycosis. Some species can produce mycotoxins including Ochratoxin, which is damaging to the kidneys and liver and is also a suspected carcinogen; there is also evidence that impairs the immune system. It also produces Citrinin that can cause renal damage, vasodilatation, and bronchial constriction and Gliotoxin, which is immunosuppressive. Patulin is another of its mycotoxins that is believed to cause hemorrhaging in the brain and lungs and is usually associated with apple and grape spoilage. It can also cause extrinsic asthma. P. camemberti has been responsible for inducing occupational allergies among those who work with soft white cheeses on which the fungus grows (cheese washer’s lung). P. marneffei is the major pathogenic species causing infections of the lymphatic system, lungs, liver, skin, spleen, and bone, and is also the only species of the genus to have a yeast-like phase induced by temperature. Penicillium sp. are recognized by their dense brush-like spore-bearing structures. (A_w -0.78-0.86). Culture - Potato dextrose agar or Malt extract agar, 20° – 25°C, 7 – 10 days.