Due to its abundant presence in the environment, and its preference for damp conditions, S. marcescens is commonly found growing in bathrooms (especially on tile grout, shower corners, toilet water lines, and basins), where it manifests as a pink, pink-orange, or orange discoloration and slimy film feeding off phosphorus-containing materials or fatty substances such as soap and shampoo residue.

Rinsing and drying surfaces after use can also prevent the establishment of the bacterium by removing its food source and making the environment less hospitable.

Due to this, and because S. marcescens produces a reddish-orange tripyrrole dye called prodigiosin, it may cause staining of the teeth.

It is differentiated from other Gram-negative bacteria by its ability to perform casein hydrolysis, which allows it to produce extracellular metalloproteinases which are believed to function in cell-to-extracellular matrix interactions.

[23] S. marcescens was discovered in 1819 by Venetian pharmacist Bartolomeo Bizio, as the cause of an episode of blood-red discoloration of polenta in the city of Padua.

[24] Bizio named the organism four years later in honor of Serafino Serrati, a physicist who developed an early steamboat; the epithet marcescens (Latin for 'decaying') was chosen because of the dyestuff's rapid deterioration (Bizio's observations led him to believe that the organism decayed into a mucilage-like substance upon reaching maturity).

Although the Navy later claimed the bacteria were harmless, beginning on September 29, 11 patients at a local hospital developed very rare, serious urinary tract infections.

[31] The bacterium was also combined with phenol and an anthrax simulant and sprayed across south Dorset by US and UK military scientists as part of the DICE trials which ran from 1971 to 1975.

In early 2008, the U.S. Food and Drug Administration issued a nationwide recall of one lot of Pre-Filled Heparin Lock Flush Solution USP.

[34] All of the patients involved were receiving total parenteral nutrition at the time; the two pharmacists responsible for formulating the solution were criminally charged.

[35] Because of its ability to be grown on agar plates into even, well coloured lawns, and the existence of a phage specific to S. marscecens, it has been used to trace water flows in karst limestone systems.

However, recent clinical data has shown declining efficacy for gentamicin and tobramycin, part of a trend towards increasing resistance and a narrowing of treatment options.

In 2017, the World Health Organization (WHO) listed Serratia as among the most critical group of bacteria for which new antibiotics are urgently needed due to its resistance to multiple drugs and threat to hospitals, nursing homes, and patients who use ventilators and blood catheters.

[38][39] S. marcescens skin infections are uncommon, but may be suspected in cases of cellulitis in immunocompromised individuals, particularly when conventional antibiotics are ineffective.