Serratia marcescens has an interesting and many-faceted history. The presence of the red pigmented organism on starchy food products long had been noted and was thought to be blood; its presence on consecrated wafers was thought to be the blood of Christ. It was not until 1819 that Bizio, a pharmacist, demonstrated that a microorganism was responsible for the red pigment. He named this microorganism Serratia marcescens; Serratia in honor of Serafino Serrati, an Italian physicist who invented the steamboat and marcescens from the Latin, “to decay.”
Because of the pigment production and because Serratia marcescens was believed to be a benign, saprophytic organism, it was used widely as a biological marker from 1906 to 1968. This use has been controversial in regard to experiments conducted by the US Army involving biological warfare techniques. In addition, the recognition in the 1950s of the ability of this organism to cause nosocomial infections has curtailed its use as a biological marker. Serratia marcescens is now recognized as a cause of serious infections in man. It has been implicated in practically every kind of infection and is a particularly serious problem with nosocomial infections.