4 days after a patient received a gunshot wound of the middle third of the thigh soft tissues his condition suddenly began deteriorating. There are complaints of bursting pain in the wound; pain increases during the last 12 hours. Edema of skin and hypodermic tissue quickly grows. Body temperature is 38,2°C, heart rate is 102/min. The wound edges gape, are dull in color; the muscles, viable as of day before, now protrude into the wound, look boiled, are dull in colour, have dirty-grey coating and fall apart when being held with forceps. What infection has developed in the wound?