the death of muscle fibers. Progressive, or clostridial, myonecrosis is caused by the anaerobic bacteria of the genus Clostridium. Seen in deep wound infections, progressive myonecrosis is accompanied by pain, tenderness, a brown serous exudate, and a rapid accumulation of gas within the muscle tissue.The affected muscle turns a blackish green.een in deep wound infections, progressive myonecrosis is accompanied by pain, tenderness, a brown serous exudate, and a rapid accumulation of gas within the muscle tissue. The affected muscle turns a blackish green.