When a wound is infected with Mycobacterium tuberculosis, which is an acid-resistant bacterium, it causes caseous necrosis at the site of infection, resulting in an abscess. Unlike abscesses caused by other bacteria, this abscess has no redness or swelling, and is medically called a cold abscess. Patients infected with tuberculosis may also have low fever, night sweats, loss of appetite, weakness, emaciation and other conditions, and there are infectious sources, such as pulmonary or intestinal tuberculosis.