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NAME: Clostridium spp. (excluding C. botulinum, C. difficile, C. perfingens, C. tetani)

SYNONYM OR CROSS REFERENCE: Common Clostridium pathogens include: Clostridium novyi Footnote 1, Footnote 2, C. septicum, C. sordellii, C. baratii, C. carnis, C. fallax, C. haemolyticum, C. histolyticum, C. limosum, C. bifermentans, C. clostridioforme, C. ramosum, C. sporogenes, C. tertium Footnote 3, C. innocum, C. paraputificum, C. subterminale, clostridial bacteremia Footnote 4, clostridial myonecrosis Footnote 5.

CHARACTERISTICS: Clostridium is a genus of gram-positive, spore-forming bacteria belonging to the family Clostridiaceae. Vegetative cells are rod shaped and arranged in pairs or short chains. The majority of species are obligate anaerobes; however, some species can grow under aerobic conditions or are aerotolerant. There are close to 200 species of Clostridium, with only a few species being pathogenic to humans. Several species produce toxins Footnote 1, Footnote 3.


PATHOGENICITY/TOXICITY: Pathogenic species are not invasive; however, certain strains of Clostridium produce toxins that cause symptoms and lesions associated with infection, such as tissue necrosis (C. novyi, C. septicum, S. sordellii) or botulism (C. baratii) Footnote 6. Unique strains of C. baratii and C. butyricum can, in addition to C. botulinum and C. argentinense (formerly C. botulinum type G) produce botulinum neurotoxin Footnote 3.

Illnesses primarily associated with Clostridium spp. are:

Clostridial bacteremia: Symptoms can vary greatly but will typically include fever, chills, and leukocytosis Footnote 4. The fatality rate ranges from 25-50% Footnote 2. Many Clostridium spp. can be associated with anaerobic bacteremia including C. septicum, C. ramosum, C. clostridioforme, or C. tertium Footnote 2, Footnote 7.

Clostridial Myonecrosis (Gas Gangrene): A rare but extremely fatal disease that results from the infection of muscle tissue by exotoxin producing Clostridium bacteria Footnote 5. Typical symptoms include severe pain in affected area, fever and tachycardia. Skin discoloration, appearance of haemorrhagic bullae, and subcutaneous gas appear in the late stages of infection Footnote 8. The most common cause of clostridial myonecrosis is C. perfringens Footnote 9. Approximately 70% of clostridial myonecrosis cases result from traumatic injury, and of these, about 80% are due to C. perfringensFootnote 10. Several other Clostridium spp. have been associated with cases of clostridial myonecrosis, including C. septicum, C. novyi, C. histolyticum, C. bifermentans, C. tertium, C. fallax, and C. sordellii Footnote 1, Footnote 3, Footnote 9, Footnote 10.

Necrotizing Enterocolitis (NEC): NEC is marked by ischemic necrosis of the intestinal mucosa, and is the most common gastrointestinal emergency in infants (1 to 3 cases per 1,000 live births) Footnote 4, Footnote 11. The etiology of NEC is not understood, although bacterial colonization of the gut is believed to play a role Footnote 11. Clostridium spp. have been particularly associated with more severe cases of NEC Footnote 4, Footnote 11.

Clostridium sordellii Toxic Shock Syndrome (CSTS): C. sordellii is one of the causes of toxic shock syndrome associated with gynaecological procedures, childbirth, and abortion Footnote 12. CSTS is marked by the rapid onset of severe illness with shock (edema, effusion, profound leukocytosis and hemoconcentration, followed by shock and multiorgan failure), and often occurs in previously healthy persons. The incidence of CSTS is not well characterized.

EPIDEMIOLOGY: Clostridium spp. occur worldwide and are widespread in the environment; commonly found in soil, feces, sewage, and marine sediments Footnote 3. Clostridial bacteremia and myonecrosis are relatively rare; people with underlying medical conditions and the elderly have an increased risk of developing infections Footnote 2, Footnote 3, Footnote 7, Footnote 13. Outbreaks of clostridial myonecrosis have been reported among injection drug users Footnote 14, Footnote 15.

HOST RANGE: Can inhabit the gastrointestinal tract of vertebrates and invertebrates Footnote 1, Footnote 3.


MODE OF TRANSMISSION: Contamination of wound sites and breaches in gastrointestinal tract; spontaneous cases can also occur Footnote 8.

INCUBATION PERIOD: 6 hours to 3 days for clostridial myonecrosis Footnote 5.

COMMUNICABILITY: Not directly transmitted from person-to-person.


RESERVOIR: Clostridium spp. are ubiquitous Footnote 1: humans, animals and the environment Footnote 1, Footnote 3.

ZOONOSIS: No, there is no evidence that Clostridium spp. can be transmitted directly from animals to humans Footnote 16.



DRUG SUSCEPTIBILITY/RESISTANCE: Antibiotic susceptibility for Clostridium spp. can vary Footnote 3, Footnote 4; however, most species are susceptible to penicillin, clindamycin, chloramphenicol, piperacillin, metronidazole, imipenem, and combinations of b-lactams with b-lactamase inhibitors Footnote 3, Footnote 9, Footnote 12.

SUSCEPTIBILITY/RESISTANCE TO DISINFECTANTS: Spores are resistant to most disinfectants and, when susceptible, they require longer contact time Footnote 17-Footnote 19. Clostridium spores are resistant to ethyl and propyl alcohols Footnote 17. Spores of Clostridium spp. can be killed by high level disinfectants such as 2% aqueous glutaraldehyde within 3 hours, 8% formaldehyde, 20 ppm sodium hypochlorite Footnote 17, Footnote 19.

PHYSICAL INACTIVATION: Spores of the genus Clostridium are generally heat resistant Footnote 18, Footnote 20 and can withstand temperature of 116 °C for 3 hours, whereas there vegetative cells can be rapidly killed by temperatures of only 55 to 65 °C Footnote 20. Spore can, however, be killed by saturated steam under pressure of 15 pounds at 121 °C Footnote 21. Spores can also be killed by moist heat at 100 °C in 29 minutes when suspended in pH 7 and in 11 minutes when suspended in pH 10.2 or 4.1 Footnote 20.

SURVIVAL OUTSIDE HOST: Clostridium spp. are able to form resistant endospores which are ubiquitous in the environment Footnote 3.


SURVEILLANCE: Monitor for symptoms. Can be diagnosed based on clinical presentation and direct isolation of bacteria from samples Footnote 3, Footnote 13. Puncture wounds should be observed for abscess formations and gas in tissue; conditions which require rapid clinical diagnosis if present Footnote 3.

FIRST AID/TREATMENT: Antibiotic treatment and surgical removal of infected tissue in cases of clostridial myonecrosis Footnote 3, Footnote 4, Footnote 8.


PROPHYLAXIS: Cleaning any wound sites with an antiseptic; antibiotic may be prescribed Footnote 1.


LABORATORY-ACQUIRED INFECTIONS: At least six cases of laboratory-acquired infections with Clostridium spp. have been reported up to 1976 Footnote 22.

SOURCES/SPECIMENS: Blood, feces, or biopsy and/or wound samples Footnote 3, Footnote 23.

PRIMARY HAZARDS: Parenteral inoculation.



RISK GROUP CLASSIFICATION: Risk Group 2. This risk group applies to the Clostridium genus as a whole, and may not apply to every species within the genus.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for all work involving infected or potentially infected material Footnote 24. These containment requirements apply to the Clostridium genus as a whole, and may not apply to each species within the genus.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 24.

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 24.


SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up Footnote 24.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 24.

STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled Footnote 24.


UPDATED: December, 2011

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Public Health Agency of Canada, 2011


Footnote 1
Poxton, I. R. (2006). Other Clostridium spp. In S. H. Gillespie, & P. M. Hawkey (Eds.), Principles and Practice of Clinical Bacteriology (2nd ed., pp. 567-574). West Sussex: John Wiley & Sons, Ltd.

Footnote 2
Leal, J., Gregson, D. B., Ross, T., Church, D. L., & Laupland, K. B. (2008). Epidemiology of Clostridium species bacteremia in Calgary, Canada, 2000-2006. Journal of Infection, 57(3), 198-203.

Footnote 3
Johnson, E. A., Summanen, P., & Finegold, S. M. (2007). Clostridium. In P. R. Murray (Ed.), Manual of Clinical Microbiology (9th ed., pp. 889-910). Washington, D.C.: ASM Press.

Footnote 4
Brook, I. (2009). The role of anaerobic bacteria in bacteremia. Anaerobe,

Footnote 5
Dylewski, J., Drummond, R., & Rowen, J. (2007). A case of Clostridium septicum spontaneous gas gangrene. Canadian Journal of Emergency Medicine, 9(2), 133-135.

Footnote 6
Popoff, M. R., & Bouvet, P. (2009). Clostridial toxins. Future Microbiology, 4, 1021-1064. doi:10.2217/fmb.09.72

Footnote 7
Rechner, P. M., Agger, W. A., Mruz, K., & Cogbill, T. H. (2001). Clinical features of clostridial bacteremia: A review from a rural area. Clinical Infectious Diseases, 33(3), 349-353.

Footnote 8
Chipp, E., Phillips, C., & Rubin, P. (2009). Successful management of spontaneous Clostridium septicum myonecrosis. Journal of Plastic, Reconstructive and Aesthetic Surgery, 62(10), e391-e393.

Footnote 9
Onderdonk, A. B., & Garrett, W. S. (2009). Gas Gangrene and Other Clostridium-Associated Diseases. In G. L. Mandell, J. E. Bennett & R. Dolin (Eds.), Mandell, Douglas, and Bennett's Principles and Practices of Infectious Diseases (7th Edition ed., ). New York: Churchill Livingston.

Footnote 10
Stevens, D. L., & Bryant, A. (2011). Clostridium myonecrosis.

Footnote 11
Schanler, R. J. (2011). Pathology and pathogenesis of necrotizing enterocolitis in newborns.

Footnote 12
Spelman, D. (2011). Toxic shock syndrome due to Clostridium sordellii.

Footnote 13
Smith-Slatas, C. L., Bourque, M., & Salazar, J. C. (2006). Clostridium septicum infections in children: A case report and review of the literature. Pediatrics, 117(4), e796-e805.

Footnote 14
Bangsberg, D. R., Rosen, J. L., Aragón, T., Campbell, A., Weir, L., & Perdreau-Remington, F. (2002). Clostridial myonecrosis cluster among injection drug users: A molecular epidemiology investigation. Archives of Internal Medicine, 162(5), 517-522.

Footnote 15
McGuigan, C. C., Penrice, G. M., Gruer, L., Ahmed, S., Goldberg, D., Black, M., Salmon, J. E., & Hood, J. (2002). Lethal outbreak of infection with Clostridium novyi type A and other spore-forming organisms in Scottish injecting drug users. Journal of Medical Microbiology, 51(11), 971-977.

Footnote 16
Songer, J. G. (2010). Clostridia as agents of zoonotic disease. Veterinary Microbiology, 140(3-4), 399-404.

Footnote 17
Rutala, W. A. (1996). APIC guideline for selection and use of disinfectants. American Journal of Infection Control, 24(4), 313-342.

Footnote 18
Ryan, J. R. (2004). Clostridium, Peptostreptococcus, Bacteroids, and other Anaerobes. In K. J. Ryan, & C. G. Ray (Eds.), Sherris Medical Microbiology: An Introduction to Infectious Diseases (4th ed., pp. 309-326). USA: McGraw-Hill.

Footnote 19
Russel, A. D. (2001). Chemical Sporicidal and Sporostatic Agents. In S. S. Block (Ed.), Disinfectaion, Sterilization and Preservation (5th ed., pp. 529-541). Philadelphia PA: Lippincott Williams and Wilkins.

Footnote 20
Schneierson, S. S. (1972). Sterilization by heat. International Anesthesiology Clinics, 10(2), 67-83.

Footnote 21
Hoyt, A., Chaney, A. L., & Cavell, K. (1938). Studies on Steam Sterilization and the Effects of Air in the Autoclave. Journal of Bacteriology, 36(6), 639-652.

Footnote 22
Pike, R. M. (1976). Laboratory associated infections: summary and analysis of 3921 cases. Health Laboratory Science, 13(2), 105-114.

Footnote 23
Collins, C. H., & Kennedy, D. A. (1999). Laboratory acquired infections. Laboratory acquired infections: History, incidence, causes and prevention (4th ed., pp. 1-37). Woburn, MA: BH.

Footnote 24
Public Health Agency of Canada. (2004). In Best M., Graham M. L., Leitner R., Ouellette M. and Ugwu K. (Eds.), Laboratory Biosafety Guidelines (3rd ed.). Canada: Public Health Agency of Canada.