Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Meningococcal Infections ?
    ### Response:
    Meningococci are a type of bacteria that cause serious infections. The most common infection is meningitis, which is an inflammation of the thin tissue that surrounds the brain and spinal cord. Meningococci can also cause other problems, including a serious bloodstream infection called sepsis.
    