Chapter 6: Plastic Surgery. - Famona Site

AetiologyThe causative organism responsible for gas gangrene can be any of the 150 speciesof Clostridia. Clostridia are gram-positive, spore-forming, encapsulated, obligate anaerobebacilli which can be motile or non-motile, depending on the species. Most are soil or foreignmaterial contaminants but the organism has also been isolated from the gallbladder, stomach,small intestine, colon, vagina and occasionally, the skin of normal healthy individuals.Although Clostridium species thrive under anaerobic conditions, some are reasonablyaerotolerant. Some strains of Clostridium perfringens can survive exposure to oxygen for aslong as 72 hours. This is important when therapy is planned.Clostridia are gram-positive organisms, but many species appear to be gram-negative,especially in clinical material or in late cultures. For this reason the staining characteristicsshould not be an absolute guideline in diagnosis.Clostridium perfringens has been implicated, either alone or in combination with otherorganisms, in the majority of gas gangrene infections. The clostridial species reported ascausative agents of gas gangrene are listed in table 6.4.1.Table 6.4.1. Clostridial species causing or associated with gas gangreneC. perfringensC. septicumC. novyiC. histolyticumC. bifermentansC. sporogenesC. fallaxC. tertiumC. butyricumC. paraputricumC. sartagoforumC. sordelliC. capitovalesGroup I Toxogenic and ProteolyticGroup II ProteolyticGroup III Contaminant- Group I includes the species that cause the classical syndrome. They have toxogenicand proteolytic capabilities.- Group II augment an infection by their proteolytic capabilities, but are not toxogenic.- Group III are wound contaminants only.33