Large gram-positive bacilli with blunt ends
May be subterminal spores evident on gram stain (suggesting C. septicum - see image above)
Rapid growth in the laboratory (mirroring what is seen clinically)
Clostridium perfringens is a large, anaerobic Gram positive rod. It produces oval spores, but these are rarely seen in clinical specimens, or when the organism is grown on artifical media. Clostridium perfringens is divided into 5 serogroups based on the production of toxins. Its major habitat is the soil and the intestines of humans and other animals. However, only type A is found in the microflora of both the soil and intestine. Clostridium perfringens is responsible for 90% of the cases of gas gangrene, a rapidly progressive infection characterized by muscle necrosis and systemic toxicity. All types produce alpha toxin, a lecithinase which cleaves lecithin to phosphoryl choline and diglyceride. It is thought to be the most important toxin in gas gangrene. Clostridium perfringens type A also produces a heat labile enterotoxin, which causes an acute, self-limited gastritis. It is a common cause of food poisoning worldwide.
Management
Prompt surgical exploration
- to define the nature of the process (gas gangrene Vs crepitant cellulitis)
- for appropriate debridement
Antimicrobial therapy
- Clindamycin (for its anti-toxin effects), penicillin plus ciprofloxacin
Hyperbaric oxygen - Role unclear. May play a role when debridemenet is difficult to achieve. e.g. extensive involvement of the trunk.
Non-clostridial (crepitant) myositis
1. Anaerobic streptococcal myonecrosis
2. Synergistic nonclostridial anaerobic myonecrosis
3. Infected vascular gangrene
4. Aeromonas hydrophila myonecrosis
