Penicillium Mold Allergy Should Not be Confused with Penicillin Allergy

Penicillium vs Penicillin

Sometimes allergy skin tests show a positive indication for the mold Penicillium. This does not mean that the patient is also allergic to Penicillin, the antibiotic.

The mold Penicillium chrysogenum (also known as Penicillium notatum) secretes the antibiotic Penicillin into the space outside its cells. The goal is to kill ordinary bacteria around the mold, because they compete with the mold for food and water. This can be seen as a clear space when Penicillium is grown in a culture dish. Alexander Fleming first noticed this in 1928.

Fleming shown with culture - penicillium vs penicillinThe discovery of penicillin was really a lucky set of coincidences. Fleming went away for a weekend but neglected to clean up his bacterial experiments with Staphylococcus aureus, leaving the petri dishes out on the lab bench. Back from vacation, Fleming was sorting through the long unattended stacks to determine which ones could be salvaged. While picking up one particular dish, Fleming noticed something strange about it. While he had been away, a mold had grown on the dish. That in itself was not strange. However, this particular mold seemed to have killed the Staphylococcus aureus that had been growing in the dish. Fleming realized that this mold had potential. The area around the ring-shaped mold was free of the staphyloccus bacteria. The mold was penicillium notatum. Fleming realized the bacteria had been killed by something coming from the mold.

Fleming conducted additional research on the mold. He tested it against other bacteria on small animals. He noted there were no side effects. Ten years later, two Oxford University researchers, Earnest Chain and Howard Florey isolated the substance in the mold that killed bacteria. It was penicillin.

Not all strains of Penicillium chrysogenum ( P. notatum) produce penicillin. It can be any of various bluish-green fungi that grow as molds on decaying fruits and ripening cheese. Some species are used in food production, for example Penicillium camemberti that is used to make Brie and Camembert cheeses. Some species have been tentatively linked to disease in humans, most notably in immunocompromised patients. Other species of Penicillium are toxic, producing the carcinogenic toxin ochratoxin.

Penicillium is a common indoor mold and allergy to this fungus is unrelated to a penicillin allergy. Symptoms tend to occur in a seasonal pattern, as spore production by molds tends to increase and decrease with changes in seasons. The specific symptoms that can result can vary amongst patients. The symptoms may include: respiratory problems, skin rash, sneezing, itchy eyes and other asthma-like symptoms. See Black Mold Symptoms for more information.

If you have questions about Penicillin or Penicillium allergies, ask your doctor.