Microorganism "a wonderful wand"

Serratia marcescens used to be called Bacterium prodigiosum or "a wonderful wand". The appearance of this sufficiently safe microorganism for human beings on foodstuffs, icons, altars caused panic. The fact is that this microbe synthesizes a blood-red pigment, and the appearance of icons that weep with bloody tears, or bread with blood-red spots, was perceived by people as a terrible sign.

There is an ancient legend that during the siege of Tire in the army of Alexander the Great, panic arose because of the "blood stains" on the bread. But the sage reassured the soldiers, explaining the "bloody stains" by the fact that a bloody massacre of the enemy is expected.