Clostridium spp

Gram Stain

• Gram positive bacilli (anaerobic)

Clinical Significance

These organisms are found in the environment (soil) and in the gastrointestinal tract. 

Clostridium spp. are encountered in a wide variety of clinical settings ranging from contamination of wounds to cellulitis, bacteremia, abscesses, intra-abdominal sepsis, gangrene, myonecrosis, and septicemia.  Gas gangrene is toxin mediated and caused most frequently by C. perfringens, but also by C. novyi, C. septicum, C. haemolyticum, C. sordellii, C histolyticum, and C. bifermentans. 

Other toxin mediated clostridial infections include botulism (C. botulinum), food poisoning (C. perfringens), and tetanus (C. tetani). 

Clostridium spp. are usually involved in polymicrobial infections including intra-abdominal, pelvic, pleuropulmonary, central nervous system, and skin/soft tissue infections.

C. septicum – over 50% of patients with bacteremia have gastrointestinal abnormality such as diverticular disease or malignancy.

Usual Susceptibility Pattern

C. perfringens is typically susceptible to most anti-anaerobic agents including penicillins, carbapenems, and metronidazole.

Penicillin susceptibility is variable for non C. perfringens species (C. clostridioforme, C. ramosum, C. butyricum, C. glycolicum) due to beta-lactamase production or decreased affinity to penicillin binding proteins.

Susceptibility to clindamycin is variable. 

Cephalosporins (including cefoxitin), and quinolones (including moxifloxacin) do not have reliable activity against Clostridium spp. 

These organisms are susceptible to vancomycin (except C. inocuum).

Note:  C. tertium is aerotolerant and may exhibit resistance to beta lactam antibiotics, clindamycin, and metronidazole.  It tends to be susceptible to vancomycin.