Scientifically, a facultative anaerobic organism is one that can produce adenosine triphosphate by either fermentation or aerobic respiration depending on the availability of oxygen. Basically this process means that the organism is capable of deriving energy and replicating with or without the presence of oxygen. Most commonly these types of organisms are facultative bacteria, but other organism types such as fungi, yeasts, and aquatic invertebrates can also be classified as a facultative anaerobe. In addition, some white blood cells within the human body meet the necessary criteria and fall into the same facultative anaerobe grouping. One example of a frequent type of these organisms is brewer’s yeast. Normally it consumes oxygen, but switches to fermentable sugar when it is readily available. Common facultative bacteria pathogens are Staphylococcus, Escherichia coli, Corynebacterium, and Listeria.

Staphylococcus infections can be the cause of a varied assortment of diseases and conditions in humans, most frequently manifested as food poisoning. Other complications caused by this bacteria are zoonosis and genitourinary tract infections. Escherichia coli, or E. coli for short, is one of the leading causes of food poisoning, usually resulting from the consumption of undercooked meat or vegetables that have not been washed. While this bacteria occurs normally in the digestive tract, it can become pathogenic if it acquires certain genetic elements. In addition, several other complications can result from the bacteria, including the following conditions: gastroenteritis, neonatal meningitis, urinary tract infections, peritonitis, septicemia, mastitis, and pneumonia. Corynebacterium are relatively harmless, but can be the cause for the condition of diphtheria, a rare infection found mainly in developing countries. Listeria is found commonly in nature and can cause a rare type of food poisoning known as listeriosis due to uncooked meat and vegetable consumption. Listeriosis has a high case fatality rate of nearly 25%.

Treatment options for infections resulting from facultative sources can be widely varied depending on the specific condition that has been contracted. For food poisoning, the condition can be detected by the presence of the following symptoms: nausea, diarrhea, headaches, fevers, vomiting, and milt to severe abdominal cramping. Plenty of water should be consumed as frequent vomiting and diarrhea can leave the body severely dehydrated. Alcoholic and drinks containing caffeine or high sugar levels should be avoided. The body’s immune system can usually control the infection after a few days, but in rare cases medications may be needed to aid in a speedy recovery.

Those organisms that are able to reproduce without the aid of oxygen can be a dangerous and deadly threat when they cause diseases. However, treatment options do exist and a local physician should be consulted to determine the best course of action for treatment. While encounters with a facultative anaerobic organism are extremely common, care should be taken to properly prepare food and prevent food poisoning.