A bacterium that is part of the normal flora of the intestinal tract of many healthy people causes a Serratia infection. Other closely related infections include Klebsiella and Enterobacter. These infections are most common in people living in long-term care facilities, according to the Merck Manual, Consumer Version.
Serratia infections sometimes affect the urinary or respiratory tract of the patient, warns the Merck Manual Consumer Version. Such infections sometimes lead to pneumonia, bladder infections and kidney infections. The infection may also occur in burns or in openings made by medical personnel, such as surgical wounds and intravenous catheters.
If the bacterial infection enters the bloodstream, it may cause bacteremia and sepsis, according to the Merck Manual, Consumer Version. The blood is normally sterile, and the body has the ability to filter any bacteria that finds its way into it. When the body removes the bacteria on its own, there are generally no symptoms. However, if the bacteria continue to grow, the immune system triggers a bodywide response, resulting in fever, a rapid respiratory rate and heartbeat, and an increase in the number of white blood cells.
Treatment for any of these three bacterial infections usually involves intravenous antibiotics. Infections from the general community usually respond to treatment. However, infections from health care facilities are more difficult to treat because they are often antibiotic resistant, according to the Merck Manual, Consumer Version.