Produces prodigiosin at 25°C giving a red appearance; very ubiquitous (bathrooms and water); can be a human pathogen (UTI and catheter bacteremia); 1970s US and UK tested effects by spraying; church wafer story (middle ages).
A) Serratia marcescens
B) Escherichia coli
C) Pseudomonas aeruginosa
D) Clostridium difficile
