[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Gram-positive rods](https://durgical.com/en/microbiology/groups/gram-positive-rods/) › Other invasive clostridia # 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. Updated Nov 13, 2026 Also called: Clostridium septicum, Paeniclostridium (Clostridium) sordellii ## Quick facts **Type** Bacterium · [Gram-positive rods](https://durgical.com/en/microbiology/groups/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 On this page - The basics Key points - At a glance - Morphology - Transmission - Memory aid - What the colours mean - Clinical Virulence factors - Diseases it causes - Clinical picture - Diagnosis - Treatment Treatment - Prevention - Study Test yourself - Connections Connections ## Key points - Gas gangrene without trauma: C. septicum, look for colon cancer. - C. septicum is associated with colorectal cancer and neutropenia. - Toxic shock after childbirth or abortion, without fever and with extreme leukocytosis: C. sordellii. - Treatment: surgery plus penicillin and clindamycin (or a broad beta-lactam). ## 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 →](https://durgical.com/en/conditions/colorectal-cancer/) - Neutropenic enterocolitis in patients with blood cancers (C. septicum) [Febrile neutropenia →](https://durgical.com/en/conditions/febrile-neutropenia/) - Toxic shock syndrome, usually without fever (C. sordellii) [Toxic shock syndrome →](https://durgical.com/en/conditions/toxic-shock-syndrome/) - Endometritis after childbirth, miscarriage or abortion (C. sordellii) [Puerperal infection (postpartum endometritis and maternal sepsis) →](https://durgical.com/en/conditions/puerperal-infection/) ## 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: - [Benzylpenicillin (penicillin G)](https://durgical.com/en/pharmacology/benzylpenicillin/) - [Clindamycin](https://durgical.com/en/pharmacology/clindamycin/) - [Piperacillin + tazobactam](https://durgical.com/en/pharmacology/piperacillin-tazobactam/) - [Metronidazole](https://durgical.com/en/pharmacology/metronidazole/) - [Meropenem](https://durgical.com/en/pharmacology/meropenem/) ## 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 ## Memory aid «Septicum searches the colon»: if it grows in blood, the colonoscope goes looking for the tumour. «Sordellii is silent»: shock without fever after a pregnancy ends. ## 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. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/microbiology/other-invasive-clostridia/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. ## Connections ## Related 4 - [Clostridium perfringens](https://durgical.com/en/microbiology/clostridium-perfringens/) - [Clostridioides difficile](https://durgical.com/en/microbiology/clostridioides-difficile/) - [Clostridium tetani](https://durgical.com/en/microbiology/clostridium-tetani/) - [Streptococcus pyogenes](https://durgical.com/en/microbiology/streptococcus-pyogenes/) ## Related conditions 4 - [Colorectal cancer](https://durgical.com/en/conditions/colorectal-cancer/) - [Febrile neutropenia](https://durgical.com/en/conditions/febrile-neutropenia/) - [Toxic shock syndrome](https://durgical.com/en/conditions/toxic-shock-syndrome/) - [Puerperal infection (postpartum endometritis and maternal sepsis)](https://durgical.com/en/conditions/puerperal-infection/) [← Back to the group: Gram-positive rods](https://durgical.com/en/microbiology/groups/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](https://www.msdmanuals.com/professional/infectious-diseases/anaerobic-bacteria/overview-of-clostridial-infections) (MSD Manual Professional Edition, 2025); [Clostridium septicum Gas Gangrene in Colon Cancer: Importance of Early Diagnosis](https://pmc.ncbi.nlm.nih.gov/articles/PMC4697071/) (Case Reports in Infectious Diseases, 2015); [About Clostridium sordellii | C. sordellii | CDC](https://www.cdc.gov/c-sordellii/about/index.html) (CDC, 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/other-invasive-clostridia/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/other-invasive-clostridia/