|  | Public Health Safety | Public Health

Description of Enterobacter Aerogenes

Enterobacter aerogenes is a bacterium of the family Enterobacteriaceae commonly found in the human digestive tract, as well as in waste materials, hygienic chemicals, and contaminated soil and water samples. The bacterium can cause infections and even death in humans. Although most Enterobacter infections are opportunistic, occurring in the very young, elderly or hospitalized patients. The bacterium can also cause food spoilage, particularly in syrups.

  1. The Bacterium

    • Bacteria

      Enterobacter aerogenes is a microscopic rod-shaped bacterium. The species is Gram-negative, meaning that samples do not retain crystal violet dye during staining in the lab. More importantly, Gram-negative bacteria have a complex outer membrane with a lipid layer that allows them to resist dyes and antibiotics, and causes a toxic infection when introduced into the bloodstream. The species is also catalase-positive, containing a common enzyme that allows the organism to break down hydrogen peroxide into water and oxygen. Thus, scientists can use a simple test, adding hydrogen peroxide and watching for bubbles, to verify the presence in a sample of catalase-positive bacteria like Enterobacter aerogenes.

    Pathology

    • As Enterobacter aerogenes is a common digestive bacterium in the human body, the species rarely causes infections in healthy individuals. Nonetheless, in neo-natal wards, geriatric care facilities, and among patients with debilitated immune systems, Enterobacter aerogenes can cause lower respiratory tract infections, skin and internal soft tissue infections, urinary tract infections (UTIs), septic arthritis, and bacteremia. In rare cases, acute infections can be contagious, causing community-acquired infections.

    Frequency and Mortality

    • Hospital

      According to the EMedicine site, Enterobacter infections were found by the U.S. Surveillance and Control of Pathogens of Epidemiological Importance (SCOPE) project to be the second most common gram-negative bacterial cause of nosocomial, hospital-acquired infections, accounting for 4.7 percent of blood infections in Intensive Care Units (ICUs) and 3.1 percent of infections outside of the ICU. Most at-risk were patients receiving sustained antibiotic treatments, invasive surgery or catheters, as well as those hospitalized for more than 2 weeks.

      Enterobacter infections, which usually take hold when the immune system is already weak, are rarely the direct cause of death, but can accelerate the deterioration of underlying or secondary conditions.

    Symptoms

    • Symptoms for respiratory, urinary or skin infections caused by Enterobacter bacteria are similar to the general symptoms of these conditions when caused by other bacterial infections.

      Bacteremia caused by Enterobacter infection often causes an increased heart rate, rapid breathing and fever. Extreme cases can involve hypertension, shock and even death.

    Prevention

    • Washing hands

      Enterobacter is harmless for most individuals with healthy immune systems. Yet, basic prevention behaviors, as with all bacterial infections, are important. These include good hygiene and proper cleaning or disposal of any material that may have come into contact with human waste. These preventive measures are especially important in environments such as hospitals with populations of individuals with immune deficiencies. Additionally, overuse of antibiotics can also increase susceptibility to Enterobacter infection.

    Food Spoilage

    • Enterobacter aerogenes releases hydrogen gas during fermentation, which can spoil syrups and molasses. The bacterium, however, has rarely been found on food samples, especially when the food has been hygienically prepared.

Public Health - Related Articles