Other invasive clostridia
- Bacterium
Gram-positive
Thick peptidoglycan wall: stains purple.- For completeness
Spore-forming bacteria that cause sudden gas gangrene without injury (linked to colon cancer) or deadly shock after childbirth or abortion.
Also called: Clostridium septicum, Paeniclostridium (Clostridium) sordellii
Quick facts
- Type
- Bacterium · Gram-positive rods
- Gram / shape
- Gram-positive · Large spore-forming rods
- Spread
- C · C · Not spread from person to person
- Causes
- Spontaneous · Bacteraemia associated
- Treatment
- Emergency surgical debridement
At a glance
- Gram
- Gram-positive
- Shape
- Large spore-forming rods
- Oxygen
- Anaerobes; C. septicum tolerates oxygen better than C. perfringens
- Family
- Clostridiaceae and related families
Morphology
- Large Gram-positive rods with subterminal spores; may look Gram-variable
- C. septicum swarms across blood agar
Transmission
- C. septicum: endogenous, from the gut through an ulcerated colon tumour or a damaged bowel wall
- C. sordellii: likely from vaginal colonisation after childbirth, miscarriage or abortion; also soil
- Not spread from person to person
Reservoir: Soil; human gut and, for C. sordellii, the vagina of some women
Isolation precautions
What the care team adds to standard precautions.
- Standard
Virulence factors
- C. septicum alpha toxin: lethal, haemolytic and necrotizing
- C. sordellii lethal and haemorrhagic toxins, related to the toxins of Clostridioides difficile, cause massive capillary leak
- Tumour hypoxia and acidity favour spore germination
Diseases it causes
- Spontaneous (non-traumatic) gas gangrene and myonecrosis (C. septicum)
- Bacteraemia associated with colorectal cancer (C. septicum) Colorectal cancer →
- Neutropenic enterocolitis in patients with blood cancers (C. septicum) Febrile neutropenia →
- Toxic shock syndrome, usually without fever (C. sordellii) Toxic shock syndrome →
- Endometritis after childbirth, miscarriage or abortion (C. sordellii) Puerperal infection (postpartum endometritis and maternal sepsis) →
Clinical picture
- C. septicum: sudden severe pain, swelling and crepitus of a limb with no wound; death can come within a day
- C. sordellii: no fever, refractory hypotension, massive oedema, haemoconcentration and extreme leukocytosis
- C. sordellii also infects newborn umbilical stumps and wounds of people who inject drugs
Diagnosis
- Blood cultures (aerobic and anaerobic) before antibiotics
- Gram stain of tissue: large Gram-positive rods with few neutrophils
- Imaging shows gas in tissue; surgery confirms necrosis
- C. septicum in blood: colonoscopy and a search for colon cancer or blood cancer
Treatment
Emergency surgical debridement (or hysterectomy in uterine infection) plus antibiotics with anaerobic activity: penicillin with clindamycin to suppress toxin production, or a broad beta-lactam such as piperacillin-tazobactam or a carbapenem, often with metronidazole.
Drug class only; doses and regimens are set by the clinician from the current guideline.
In Pharmacology:
Prevention
- Screen for colorectal cancer after C. septicum bacteraemia
- Prompt assessment of any illness after childbirth, miscarriage or abortion
- Report postpartum or post-abortion toxic shock to the health authorities
Test yourself
Think of the answer, then tap the question to see it.
Which malignancy should be sought after Clostridium septicum bacteraemia?
Colorectal cancer (and blood cancers).
What is unusual about C. sordellii toxic shock syndrome?
It usually lacks fever and shows refractory hypotension, capillary leak, haemoconcentration and extreme leukocytosis.
Why is clindamycin added to penicillin in clostridial necrotizing infection?
It suppresses bacterial toxin production.
When are women at highest risk of C. sordellii infection?
After a pregnancy ends: childbirth, miscarriage or abortion.
Connections
← Back to the group: Gram-positive rods
Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Overview of Clostridial Infections - Infectious Disease - MSD Manual Professional Edition (MSD Manual Professional Edition, 2025); Clostridium septicum Gas Gangrene in Colon Cancer: Importance of Early Diagnosis (Case Reports in Infectious Diseases, 2015); About Clostridium sordellii | C. sordellii | CDC (CDC, 2024).
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Representative model, for educational purposes only.