Citrobacter freundii is an infectious anaerobic bacterium that forms rod-like structures known as coccobacilli. This bacterium lives in the digestive tract and in many places in nature. The Public Health Agency of Canada identifies it as an opportunistic pathogen.
Citrobacter is responsible for infections in normally sterile sites in the human body, including the blood, urinary tract and respiratory tract. According to Wikipedia, it accounts for about 29 percent of all opportunistic diseases in humans. While infectious in humans, in the environment it plays the positive role of converting nitrates to nitrites, making the bacteria essential for completion of the nitrogen cycle.
Citrobacter infections are most common in infants under age 2 and in adults with compromised immune systems. Infections are fatal in up to 48 percent of those infected, according to the Public Health Agency of Canada. They are fatal in 30 percent of all infant cases, and survivors often experience significant damage to the central nervous system. The most common method of transfer of infections is person-to-person although there are also reported cases of hospital staff spreading the disease. Other methods include environmental and mother-to-child transmissions.
Citrobacter freundii is susceptible to disinfectants, such as phenolic disinfectants, 70 percent ethanol and 1 percent sodium hypochlorite. The Public Health Agency of Canada recommends medical personnel limit use of sharps when working with patients suspected to suffer from Citrobacter infections.