Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Actinomycosis ?
    ### Response:
    Actinomycosis is a chronic bacterial infection that commonly affects the face and neck. It is usually caused by an anaerobic bacteria called Actinomyces israelii. Actinomyces are normal inhabitants of the mouth, gastrointestinal tract, and female genital tract, and do not cause an infection unless there is a break in the skin or mucosa.
    