Serratia marcesans is a rod-shaped gram-negative bacterium. It is an anaerobic bacterium that reproduces by binary fission. It grows in moist conditions with a pH range of five to nine. S. marcesans are widespread in the atmosphere, but are not a common constituent of the human fecal flora. They’re capable of flourishing in various environments, including water, soil, and the digestive tracts of various animals. A couple of strains of S. marcesans are capable of producing a pigment called prodigiosin, which ranges in color from dark red to pale pink, depending on the age of the colonies. This bacterium has been known to cause a number of infections, such as pneumonia, meningitis, respiratory and urinary tract infections, etc. S. marcesans are