In many households, a pinkish residue often appears in bathrooms, particularly around drains, shower curtains, and tile grout.

While it might be mistaken for mold, this discoloration is actually caused by the bacterium Serratia marcescens.

This microorganism thrives in moist environments and feeds on fatty substances found in soap and shampoo residues.

Dr. Karan Raj, a National Health Service (NHS) surgeon, highlighted this issue, stating: “If you’ve seen this pink slime lurking in your bathroom, it’s not mold—it’s bacteria.”

He further explained that Serratia marcescens “loves damp, moist places, and enjoys munching on fatty deposits like those found in soaps and shampoos; hence why it likes to hang out in your bathroom.”

Little-known mistakes and bloopers in Little House on the Praire
Read More
Little-known mistakes and bloopers in Little House on the Praire
While generally harmless to healthy individuals, Serratia marcescens can pose health risks to certain populations. Infectious Disease Advisor notes that this bacterium “can be found in soil, water, plants, and animals,” and in homes, it “may be found in the corner of wet showers or wash basins, where it is visible due to the red-colored pigment (prodigiosin) it produces.”