Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Necrotizing fasciitis ?
    ### Response:
    What causes necrotizing fasciitis? Bacteria that can cause necrotizing fasciitis (NF) include the following: Klebsiella, Clostridium, and Escherichia coli; group A Streptococcus is the most common cause. Anyone can develop NF. Approximately 50% of necrotizing fasciitis cases caused by streptococcal bacteria occur in young and otherwise healthy individuals.
    