Pseudomonas aeruginosa is one of the most serious hospital-acquired pathogens. A common cause of lung infections, it is also found in the intestinal tract of 20 percent of all Americans and 50 percent of hospitalized patients in the United States.
It is one of the hundreds of bacteria that colonize the human intestinal tract, usually causing no apparent harm. It might even be beneficial to its host. Once the host is weakened by an illness, surgical procedure or immunosuppressive drugs, however, P. aeruginosa can cause infection, inflammation, sepsis and death.
Why P. aeruginosa can suddenly turn on its host has eluded researchers