Below is an instruction from Human. Write a response.
    ### Instruction:
    What to do for Pyelonephritis: Kidney Infection ?
    ### Response:
    - Pyelonephritis is a type of urinary tract infection that affects one or both kidneys.  - Pyelonephritis is caused by a bacterium or virus infecting the kidneys. Though many bacteria and viruses can cause pyelonephritis, the bacterium Escherichia coli is often the cause.
    