What common flora is seen in the nervous system?

The central nervous system (CNS) is normally sterile, and the presence of any bacteria or fungi is considered abnormal and indicative of infection. However, the peripheral nervous system (PNS) can be colonized by various bacteria and fungi, which are collectively referred to as the "normal flora" of the nervous system. These organisms are usually non-pathogenic and do not cause any harm to the host.

Here are some common flora that can be found in the peripheral nervous system:

1. Staphylococcus epidermidis: This is a Gram-positive bacterium that is commonly found on the skin and mucous membranes. It can occasionally colonize the peripheral nerves, especially after trauma or surgery.

2. Propionibacterium acnes: This is another Gram-positive bacterium that is commonly found on the skin. It can also colonize the peripheral nerves and may be associated with certain nerve disorders, such as neuropathy.

3. Corynebacterium species: These are Gram-positive bacteria that are commonly found on the skin and in the respiratory tract. They can occasionally colonize the peripheral nerves and may be associated with nerve infections.

4. Bacillus species: These are Gram-positive bacteria that are commonly found in the environment. They can occasionally colonize the peripheral nerves and may be associated with nerve infections.

5. Candida species: These are fungi that are commonly found on the skin and mucous membranes. They can occasionally colonize the peripheral nerves and may be associated with nerve infections, especially in immunocompromised individuals.

It's important to note that the presence of these organisms in the peripheral nervous system does not always indicate an infection. In most cases, they are harmless and do not cause any harm to the host. However, if there are signs or symptoms of nerve infection, such as pain, swelling, or loss of function, it is important to seek medical evaluation to rule out any underlying infection or other medical conditions.