The reddish bacterium to blame for this year’s shortage of flu vaccine has a colorful history.
Until the 1960s, Serratia marcescens was considered harmless — so safe, in fact, that the military secretly dispersed it across U.S. cities in germ warfare studies.
Today, Serratia is blamed for urinary tract infections, infected surgical wounds and pneumonia, usually spread among hospital patients. The germ that tainted the flu vaccine at a British factory is a common contaminant in labs — and lots of other places.
Serratia is found in people’s intestines, and possibly growing as pinkish scum in the shower, too.
“Most of us carry it every day of our lives,” said Martin Blaser, chairman of medicine at the New York University School of Medicine. “A great paradox of life and health is we have all these bad organisms we carry around OK in our intestinal tracts, and if we move them over one inch to our bladder, for example, they make us sick.”
Serratia thrives in damp places, from bathroom walls to improperly sanitized medical equipment. It is partial to bread and other starchy foods, where it shows up as blood-colored splotches.
In fact, it is considered a likely scientific explanation for the “miracle of Bolsena” in 1263, when what was believed to be Christ’s blood appeared on communion bread at a church in Bolsena, Italy. Raphael later depicted the scene in a fresco in the Vatican.
It was not until 1819 that Serratia was discovered and named by an Italian pharmacist, Bartolomeo Bizio. He found it in a dish of polenta, or cornmeal mush.
Before the 2004 flu season, Serratia was most notorious for its role in germ warfare studies.
During one such test in 1950 — “Operation Sea-Spray” — Navy vessels cruised the San Francisco coast, spewing huge amounts of the bacterium into the air over the city. At least one hospital noticed an increase in pneumonia patients.
In the 1970s, when the military disclosed the tests, a San Francisco family sued over a pneumonia death they blamed on Serratia. Courts ruled the government was immune from such lawsuits.