Caeruleus aegrus

Caeruleus aegrus (from the Latin for 'the blue sickness') is a fungal and bacterial manifestation in white dairy or yeast-based foods.

Originally thought to be a Mucoralean mold caused by cross contamination, Caeruleus Aegrus is actually the result of the interruption of the germination process by asexual spores from other bacteria. Cyanobacteria often associated with plants or algae inhibits the growth of sporangia but ruins the food product in the process

Caeruleus Aegrus is most commonly found in uncovered milk or bread products that are refrigerated in desanitized spaces, particularly those which may include food products already molded. It sometimes occurs accidentally in the pasteurization of milk .

The most common manifestation results in a blue or brown hue diffusing through the cheese, milk or bread, although the discoloring is occasionally green. The taste of the product is not initially affected, but consumption can result in severe digestive discomfort and diarrhea.