From the 5 different types of meningitis, each have their own different cause, some are: 

Bacterial meningitis: Acute bacterial meningitis usually occurs when bacteria enter the bloodstream and migrate to the brain and spinal cord.

Viral meningitis: A group of viruses known as enteroviruses is responsible for most viral meningitis cases

Fungal meningitis: Cryptococcal meningitis is a common fungal form of the disease that affects people with immune deficiencies, such as AIDS