Gas Gangrene - dismech

⚙

Pathophysiology

4

Anaerobic clostridial toxin production in infected muscle

In devitalized or otherwise permissive soft tissue, anaerobic C. perfringens proliferates and elaborates extracellular toxins and enzymes that initiate rapid skeletal-muscle necrosis.

Downstream

Alpha-toxin membrane injury Secreted alpha-toxin acts on host-cell membranes, initiating the membrane-injury step of myonecrosis.

Show evidence (1 reference)

PMID:7746141 SUPPORT BACKGROUND Model Organism

"The pathogenesis of clostridial myonecrosis, or gas gangrene, involves the growth of the anaerobic bacterium Clostridium perfringens in the infected tissues and the elaboration of numerous extracellular toxins and enzymes."

Links C. perfringens proliferation and exotoxin release to clostridial myonecrosis.

Alpha-toxin membrane injury

C. perfringens alpha-toxin is a phospholipase C/sphingomyelinase that binds target-cell membranes through its C-terminal domain and triggers membrane lipid turnover, endocytosis, and cell death.

phospholipase C activity GO:0004629 ↑ INCREASED

Downstream

Alpha-toxin and theta-toxin vascular leukostasis Alpha-toxin membrane injury, together with theta-toxin, drives the vascular leukostasis that follows.

Systemic shock and hemolysis Absorbed alpha-toxin entering the circulation produces systemic shock and erythrocyte lysis.

Show evidence (2 references)

PMID:26633512 SUPPORT Other

"Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The toxin is composed of an N-terminal domain (1-250 aa, N-domain), which is the catalytic site, and a C-terminal domain (251-370 aa, C-domain), which is the membrane-binding site."

Supports alpha-toxin as a two-domain membrane-active enzyme in gas gangrene.

PMID:7746141 SUPPORT Model Organism

"The results showed that the plc mutants had demonstrably reduced virulence and therefore provided definitive genetic evidence for the essential role of alpha-toxin in gas gangrene or clostridial myonecrosis."

Provides allelic-exchange evidence that the alpha-toxin gene plc is required for full gas-gangrene virulence.

Alpha-toxin and theta-toxin vascular leukostasis

Alpha-toxin and perfringolysin O act together to produce vascular leukostasis; toxin-damaged endothelium, platelet aggregation, leukocyte trapping, capillary leak, and impaired oxygen delivery create a self-amplifying anaerobic and necrotic muscle compartment.

vascular endothelial cell CL:0000115 skeletal muscle cell CL:0000188

platelet aggregation GO:0070527 ↑ INCREASED

Downstream

Edema Endothelial injury and capillary leak from leukostasis produce the marked localized edema of gas gangrene.

Myonecrosis Reduced arteriolar flow and anoxia from vascular leukostasis drive progressive necrosis of large muscle groups.

Pain Ischemic muscle injury produces the severe pain out of proportion to external findings characteristic of clostridial myonecrosis.

Show evidence (2 references)

PMID:10456947 SUPPORT Model Organism

"Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis observed in clostridial myonecrosis."

Supports the need for both major toxins in the leukostasis branch of experimental gas gangrene.

PMID:11111933 SUPPORT Other

"Toxin-induced endothelial dysfunction and microvascular injury could also cause loss of albumin, electrolytes, and water into the interstitial space resulting in marked localized edema. These events, combined with intravascular platelet aggregation and leukostasis, would increase venous..."

Connects endothelial injury, platelet aggregation, leukostasis, capillary leak, and edema in clostridial myonecrosis.

Systemic shock and hemolysis

Absorbed clostridial toxins can enter the systemic circulation, causing shock and multiorgan failure; in severe C. perfringens sepsis, alpha-toxin can lyse erythrocyte membranes and produce massive intravascular hemolysis.

erythrocyte CL:0000232

Downstream

Shock Toxins reaching the arterial circulation precipitate systemic shock and multiorgan failure.

Hemolytic anemia Alpha-toxin lysis of erythrocyte membranes produces massive intravascular hemolysis and hemolytic anemia.

Show evidence (2 references)

PMID:11111933 SUPPORT Other

"When toxins reach arterial circulation, systemic shock and multiorgan failure rapidly ensue, and death is common."

Supports systemic shock as a consequence of circulating clostridial toxins.

PMID:27049736 SUPPORT Human Clinical

"While C. perfringens sepsis is uncommon, it is often rapidly fatal because the alpha toxin of this bacterium induces massive intravascular hemolysis by disrupting red blood cell membranes."

Supports alpha-toxin-mediated intravascular hemolysis as a severe systemic C. perfringens branch.

⬡

Pathograph

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●

Phenotypes

6

Blood 1

Hemolytic anemia HP:0001878

Show evidence (1 reference)

PMID:27049736 SUPPORT Human Clinical

"While C. perfringens sepsis is uncommon, it is often rapidly fatal because the alpha toxin of this bacterium induces massive intravascular hemolysis by disrupting red blood cell membranes."

Supports hemolytic anemia as a rare but severe alpha-toxin-mediated complication.

Cardiovascular 1

Shock HP:0031273

Show evidence (1 reference)

PMID:11111933 SUPPORT Other

"When toxins reach arterial circulation, systemic shock and multiorgan failure rapidly ensue, and death is common."

Supports shock as a systemic consequence of toxin spread.

Metabolism 2

Fever HP:0001945

Show evidence (1 reference)

PMID:26633512 SUPPORT REVIEW SYNTHESIS Other

"Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."

Names fever among the recognized gas-gangrene manifestations.

Edema HP:0000969

Show evidence (1 reference)

PMID:11111933 SUPPORT Other

"Similarly, the direct cytotoxicity of PFO could disrupt endothelial integrity and contribute to progressive edema both locally and systemically."

Supports edema as a toxin-mediated manifestation of clostridial myonecrosis.

Musculoskeletal 1

Myonecrosis Muscle fiber necrosis HP:0003713

Show evidence (1 reference)

PMID:26633512 SUPPORT REVIEW SYNTHESIS Other

"Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."

Names myonecrosis as a defining manifestation of gas gangrene.

Constitutional 1

Pain HP:0012531

Severity: SEVERE

Show evidence (1 reference)

PMID:26633512 SUPPORT REVIEW SYNTHESIS Other

"Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."

Lists pain among the recognized gas-gangrene manifestations.

💊

Medical Actions

3

Radical surgical debridement

Action: Surgical Procedure NCIT:C15329

Gas gangrene requires urgent radical debridement of necrotic infected tissue.

Show evidence (1 reference)

PMID:18034207 SUPPORT Other

"Treatment of choice is surgical debridement of the infectious focus with radical removal of all necrotic tissue, resection of the corresponding lymphatics in addition to antibiotic therapy with penicillin G, aminoglycosides, or clindamycin or hyperbaric oxygenation."

Supports surgical debridement as the central source-control treatment for C. perfringens gas gangrene.

Antibiotic therapy

Action: Antibiotic Therapy NCIT:C15620

Agent: penicillin G CHEBI:18208 clindamycin CHEBI:3745 metronidazole CHEBI:6909

Antibiotic therapy complements source control, with toxin-suppressing agents such as clindamycin suppressing alpha-toxin activity better than penicillin alone in experimental C. perfringens gas gangrene.

Show evidence (2 references)

PMID:18034207 SUPPORT Other

"Treatment of choice is surgical debridement of the infectious focus with radical removal of all necrotic tissue, resection of the corresponding lymphatics in addition to antibiotic therapy with penicillin G, aminoglycosides, or clindamycin or hyperbaric oxygenation."

Supports antibiotics alongside radical surgery in gas-gangrene management.

PMID:2882731 SUPPORT In Vitro

"Because antibiotic efficacy did not correlate with bactericidal activity, we measured alpha-toxin activity and found complete suppression of alpha-toxin activity by tetracycline, metronidazole, rifampin, clindamycin, and chloramphenicol at concentrations equal to the MIC."

Supports toxin suppression as the rationale for protein-synthesis-inhibiting antibiotics in experimental gas gangrene.

Hyperbaric oxygen therapy

Action: hyperbaric oxygen therapy Ontology label: Hyperbaric Oxygen Therapy NCIT:C38065

Adjunctive hyperbaric oxygen is used alongside radical debridement and antibiotics in clostridial myonecrosis.

Show evidence (1 reference)

PMID:18034207 SUPPORT Other

"Treatment of choice is surgical debridement of the infectious focus with radical removal of all necrotic tissue, resection of the corresponding lymphatics in addition to antibiotic therapy with penicillin G, aminoglycosides, or clindamycin or hyperbaric oxygenation."

Names hyperbaric oxygenation among the treatment options for C. perfringens myonecrosis.

🔬

Diagnosis

3

Blood culture with Gram stain

Blood cultures growing large Gram-positive rods identify the clostridial agent in systemic C. perfringens infection.

blood culture NCIT:C25300

Show evidence (1 reference)

PMID:27049736 SUPPORT Human Clinical

"both of the 2 blood cultures obtained from the patient grew large Gram-positive rods, which were definitively identified as C. perfringens."

Blood culture growing large Gram-positive rods established the clostridial diagnosis.

Peripheral blood smear and hemolysis workup

Fulminant C. perfringens sepsis is suggested by severe hemolytic anemia with a very low MCV, a hemolyzed sample, and a negative Coombs test.

peripheral blood smear microscopy NCIT:C16853

Show evidence (1 reference)

PMID:27049736 SUPPORT Human Clinical

"C. perfringens infection should be considered in a febrile patient who has severe hemolytic anemia with a very low MCV, hemolyzed blood sample, and negative Coombs test. The characteristic peripheral blood smear findings may facilitate rapid diagnosis."

Peripheral-smear and hemolysis findings are given as the route to rapid diagnosis.

Cross-sectional imaging for soft-tissue gas

Computed tomography demonstrates gas within infected tissue or viscera, though soft-tissue gas is not universal.

computed tomography NCIT:C17204

Show evidence (1 reference)

PMID:27049736 SUPPORT Human Clinical

"Computed tomography of the abdomen showed an abscess with gas in the left lobe of the liver and emphysematous cholecystitis."

CT identified gas-forming clostridial infection in this case.

🦠

Infectious Agent

2

Clostridium perfringens

An anaerobic spore-forming bacterium whose alpha-toxin and theta-toxin drive the traumatic and postsurgical forms of clostridial myonecrosis.

Clostridium perfringens NCBITaxon:1502

Show evidence (2 references)

PMID:7746141 SUPPORT BACKGROUND Model Organism

"The pathogenesis of clostridial myonecrosis, or gas gangrene, involves the growth of the anaerobic bacterium Clostridium perfringens in the infected tissues and the elaboration of numerous extracellular toxins and enzymes."

Establishes C. perfringens as the canonical clostridial species in experimentally modeled gas gangrene.

PMID:18034207 SUPPORT Other

"Neuromuscular manifestations of C. perfringens infections are much more frequent than CNS manifestations and comprise myonecrosis (gas gangrene), rhabdomyolysis, myositis, fasciitis, affection of the neuromuscular transmission, or affection of the peripheral nerves."

Supports C. perfringens gas gangrene in human infection.

Clostridium septicum

An anaerobic clostridial species that causes rare spontaneous gas gangrene associated with malignancy or immunosuppression.

Clostridium septicum NCBITaxon:1504

Show evidence (1 reference)

PMID:18555761 SUPPORT Human Clinical

"Spontaneous Clostridium septicum myonecrosis, or gas gangrene, is an extremely rare soft tissue infection associated with malignancy and immunosuppression."

Identifies C. septicum as a cause of spontaneous gas gangrene in a human clinical report.

↔️

Transmission

1

Traumatic, postsurgical, or spontaneous clostridial seeding

C. perfringens infection usually begins at a surgical wound, trauma site, or gastrointestinal/urogenital focus, whereas spontaneous C. septicum myonecrosis reflects non-traumatic seeding in hosts with malignancy or immunosuppression.

Show evidence (2 references)

PMID:18034207 SUPPORT Other

"C. perfringens infections usually start from the site of a recent surgical wound or trauma, a gastrointestinal or urogenital problem, or occur in association with malignancy."

Supports surgical, traumatic, enteric, urogenital, and malignancy-associated portals for C. perfringens infection.

PMID:18555761 SUPPORT Human Clinical

"Spontaneous Clostridium septicum myonecrosis, or gas gangrene, is an extremely rare soft tissue infection associated with malignancy and immunosuppression."

Supports the atraumatic C. septicum branch of gas gangrene.

{ }

Source YAML

click to show

name: Gas Gangrene
creation_date: "2026-09-25T18:27:16Z"
category: Infectious Disease
disease_term:
  preferred_term: gas gangrene
  term:
    id: MONDO:0005767
    label: gas gangrene
description: >-
  Gas gangrene, or clostridial myonecrosis, is a rapidly progressive
  toxin-mediated soft-tissue infection caused mainly by Clostridium perfringens
  after trauma or surgery and less often by spontaneous Clostridium septicum
  infection in immunosuppressed or malignancy-associated settings.
parents:
- bacterial infectious disease with sepsis
- commensal bacterial infectious disease
- infection due to clostridium perfringens
- skin disease caused by bacterial infection
- vesiculobullous skin disease
synonyms:
- clostridial myonecrosis
infectious_agent:
- name: Clostridium perfringens
  infectious_agent_term:
    preferred_term: Clostridium perfringens
    term:
      id: NCBITaxon:1502
      label: Clostridium perfringens
  description: >-
    An anaerobic spore-forming bacterium whose alpha-toxin and theta-toxin drive
    the traumatic and postsurgical forms of clostridial myonecrosis.
  evidence:
  - reference: PMID:7746141
    reference_title: "Virulence studies on chromosomal alpha-toxin and theta-toxin mutants constructed by allelic exchange provide genetic evidence for the essential role of alpha-toxin in Clostridium perfringens-mediated gas gangrene."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    quote_role: BACKGROUND
    snippet: "The pathogenesis of clostridial myonecrosis, or gas gangrene, involves the growth of the anaerobic bacterium Clostridium perfringens in the infected tissues and the elaboration of numerous extracellular toxins and enzymes."
    explanation: Establishes C. perfringens as the canonical clostridial species in experimentally modeled gas gangrene.
  - reference: PMID:18034207
    reference_title: "Neuromuscular and central nervous system manifestations of Clostridium perfringens infections."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Neuromuscular manifestations of C. perfringens infections are much more frequent than CNS manifestations and comprise myonecrosis (gas gangrene), rhabdomyolysis, myositis, fasciitis, affection of the neuromuscular transmission, or affection of the peripheral nerves."
    explanation: Supports C. perfringens gas gangrene in human infection.
- name: Clostridium septicum
  infectious_agent_term:
    preferred_term: Clostridium septicum
    term:
      id: NCBITaxon:1504
      label: Clostridium septicum
  description: >-
    An anaerobic clostridial species that causes rare spontaneous gas gangrene
    associated with malignancy or immunosuppression.
  evidence:
  - reference: PMID:18555761
    reference_title: "Successful management of spontaneous Clostridium septicum myonecrosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Spontaneous Clostridium septicum myonecrosis, or gas gangrene, is an extremely rare soft tissue infection associated with malignancy and immunosuppression."
    explanation: Identifies C. septicum as a cause of spontaneous gas gangrene in a human clinical report.
transmission:
- name: Traumatic, postsurgical, or spontaneous clostridial seeding
  description: >-
    C. perfringens infection usually begins at a surgical wound, trauma site, or
    gastrointestinal/urogenital focus, whereas spontaneous C. septicum myonecrosis
    reflects non-traumatic seeding in hosts with malignancy or immunosuppression.
  evidence:
  - reference: PMID:18034207
    reference_title: "Neuromuscular and central nervous system manifestations of Clostridium perfringens infections."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "C. perfringens infections usually start from the site of a recent surgical wound or trauma, a gastrointestinal or urogenital problem, or occur in association with malignancy."
    explanation: Supports surgical, traumatic, enteric, urogenital, and malignancy-associated portals for C. perfringens infection.
  - reference: PMID:18555761
    reference_title: "Successful management of spontaneous Clostridium septicum myonecrosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Spontaneous Clostridium septicum myonecrosis, or gas gangrene, is an extremely rare soft tissue infection associated with malignancy and immunosuppression."
    explanation: Supports the atraumatic C. septicum branch of gas gangrene.
pathophysiology:
- name: Anaerobic clostridial toxin production in infected muscle
  description: >-
    In devitalized or otherwise permissive soft tissue, anaerobic C. perfringens
    proliferates and elaborates extracellular toxins and enzymes that initiate
    rapid skeletal-muscle necrosis.
  evidence:
  - reference: PMID:7746141
    reference_title: "Virulence studies on chromosomal alpha-toxin and theta-toxin mutants constructed by allelic exchange provide genetic evidence for the essential role of alpha-toxin in Clostridium perfringens-mediated gas gangrene."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    quote_role: BACKGROUND
    snippet: "The pathogenesis of clostridial myonecrosis, or gas gangrene, involves the growth of the anaerobic bacterium Clostridium perfringens in the infected tissues and the elaboration of numerous extracellular toxins and enzymes."
    explanation: Links C. perfringens proliferation and exotoxin release to clostridial myonecrosis.
  downstream:
  - target: Alpha-toxin membrane injury
    description: >-
      Secreted alpha-toxin acts on host-cell membranes, initiating the
      membrane-injury step of myonecrosis.
- name: Alpha-toxin membrane injury
  description: >-
    C. perfringens alpha-toxin is a phospholipase C/sphingomyelinase that binds
    target-cell membranes through its C-terminal domain and triggers membrane
    lipid turnover, endocytosis, and cell death.
  evidence:
  - reference: PMID:26633512
    reference_title: "Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Alpha-toxin possesses phospholipase C and sphingomyelinase activities. The
      toxin is composed of an N-terminal domain (1-250 aa, N-domain), which is
      the catalytic site, and a C-terminal domain (251-370 aa, C-domain), which
      is the membrane-binding site.
    explanation: Supports alpha-toxin as a two-domain membrane-active enzyme in gas gangrene.
  - reference: PMID:7746141
    reference_title: "Virulence studies on chromosomal alpha-toxin and theta-toxin mutants constructed by allelic exchange provide genetic evidence for the essential role of alpha-toxin in Clostridium perfringens-mediated gas gangrene."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "The results showed that the plc mutants had demonstrably reduced virulence and therefore provided definitive genetic evidence for the essential role of alpha-toxin in gas gangrene or clostridial myonecrosis."
    explanation: Provides allelic-exchange evidence that the alpha-toxin gene plc is required for full gas-gangrene virulence.
  molecular_functions:
  - preferred_term: phospholipase C activity
    modifier: INCREASED
    term:
      id: GO:0004629
      label: C-type glycerophospholipase activity
  downstream:
  - target: Alpha-toxin and theta-toxin vascular leukostasis
    description: >-
      Alpha-toxin membrane injury, together with theta-toxin, drives the
      vascular leukostasis that follows.
  - target: Systemic shock and hemolysis
    description: >-
      Absorbed alpha-toxin entering the circulation produces systemic shock and
      erythrocyte lysis.
- name: Alpha-toxin and theta-toxin vascular leukostasis
  description: >-
    Alpha-toxin and perfringolysin O act together to produce vascular leukostasis;
    toxin-damaged endothelium, platelet aggregation, leukocyte trapping, capillary
    leak, and impaired oxygen delivery create a self-amplifying anaerobic and
    necrotic muscle compartment.
  evidence:
  - reference: PMID:10456947
    reference_title: "Use of genetically manipulated strains of Clostridium perfringens reveals that both alpha-toxin and theta-toxin are required for vascular leukostasis to occur in experimental gas gangrene."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis observed in clostridial myonecrosis."
    explanation: Supports the need for both major toxins in the leukostasis branch of experimental gas gangrene.
  - reference: PMID:11111933
    reference_title: "The pathogenesis of clostridial myonecrosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Toxin-induced endothelial dysfunction and microvascular injury could also
      cause loss of albumin, electrolytes, and water into the interstitial space
      resulting in marked localized edema. These events, combined with
      intravascular platelet aggregation and leukostasis, would increase venous
      pressures and favor further loss of fluid and protein in the distal
      capillary bed.
    explanation: Connects endothelial injury, platelet aggregation, leukostasis, capillary leak, and edema in clostridial myonecrosis.
  cell_types:
  - preferred_term: vascular endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  - preferred_term: skeletal muscle cell
    term:
      id: CL:0000188
      label: cell of skeletal muscle
  biological_processes:
  - preferred_term: platelet aggregation
    modifier: INCREASED
    term:
      id: GO:0070527
      label: platelet aggregation
  downstream:
  - target: Edema
    description: >-
      Endothelial injury and capillary leak from leukostasis produce the marked
      localized edema of gas gangrene.
  - target: Myonecrosis
    description: >-
      Reduced arteriolar flow and anoxia from vascular leukostasis drive
      progressive necrosis of large muscle groups.
  - target: Pain
    description: >-
      Ischemic muscle injury produces the severe pain out of proportion to
      external findings characteristic of clostridial myonecrosis.
- name: Systemic shock and hemolysis
  description: >-
    Absorbed clostridial toxins can enter the systemic circulation, causing shock
    and multiorgan failure; in severe C. perfringens sepsis, alpha-toxin can lyse
    erythrocyte membranes and produce massive intravascular hemolysis.
  evidence:
  - reference: PMID:11111933
    reference_title: "The pathogenesis of clostridial myonecrosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "When toxins reach arterial circulation, systemic shock and multiorgan failure rapidly ensue, and death is common."
    explanation: Supports systemic shock as a consequence of circulating clostridial toxins.
  - reference: PMID:27049736
    reference_title: "Clostridium Perfringens Infection in a Febrile Patient with Severe Hemolytic Anemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      While C. perfringens sepsis is uncommon, it is often rapidly fatal because
      the alpha toxin of this bacterium induces massive intravascular hemolysis
      by disrupting red blood cell membranes.
    explanation: Supports alpha-toxin-mediated intravascular hemolysis as a severe systemic C. perfringens branch.
  cell_types:
  - preferred_term: erythrocyte
    term:
      id: CL:0000232
      label: erythrocyte
  downstream:
  - target: Shock
    description: >-
      Toxins reaching the arterial circulation precipitate systemic shock and
      multiorgan failure.
  - target: Hemolytic anemia
    description: >-
      Alpha-toxin lysis of erythrocyte membranes produces massive intravascular
      hemolysis and hemolytic anemia.
phenotypes:
- name: Myonecrosis
  phenotype_term:
    preferred_term: Myonecrosis
    term:
      id: HP:0003713
      label: Muscle fiber necrosis
  description: >-
    Coagulative necrosis of skeletal muscle is the defining lesion of clostridial
    myonecrosis and the feature the disease is named for.
  evidence:
  - reference: PMID:26633512
    reference_title: "Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: "Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."
    explanation: Names myonecrosis as a defining manifestation of gas gangrene.
- name: Fever
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
  description: Fever accompanies the systemic toxemic response in clostridial myonecrosis.
  evidence:
  - reference: PMID:26633512
    reference_title: "Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: "Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."
    explanation: Names fever among the recognized gas-gangrene manifestations.
- name: Pain
  phenotype_term:
    preferred_term: Pain
    severity: SEVERE
    term:
      id: HP:0012531
      label: Pain
  description: >-
    Severe pain, classically out of proportion to external findings, is part of
    the acute local gas-gangrene presentation.
  evidence:
  - reference: PMID:26633512
    reference_title: "Membrane-Binding Mechanism of Clostridium perfringens Alpha-Toxin."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: "Clostridium perfringens alpha-toxin is a key mediator of gas gangrene, which is a life-threatening infection that manifests as fever, pain, edema, myonecrosis, and gas production."
    explanation: Lists pain among the recognized gas-gangrene manifestations.
- name: Edema
  phenotype_term:
    preferred_term: Edema
    term:
      id: HP:0000969
      label: Edema
  description: Progressive local edema follows toxin-induced vascular leak in clostridial myonecrosis.
  evidence:
  - reference: PMID:11111933
    reference_title: "The pathogenesis of clostridial myonecrosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Similarly, the direct cytotoxicity of PFO could disrupt endothelial integrity and contribute to progressive edema both locally and systemically."
    explanation: Supports edema as a toxin-mediated manifestation of clostridial myonecrosis.
- name: Shock
  phenotype_term:
    preferred_term: Shock
    term:
      id: HP:0031273
      label: Shock
  description: Septic shock occurs when clostridial toxins and infection become systemic.
  evidence:
  - reference: PMID:11111933
    reference_title: "The pathogenesis of clostridial myonecrosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "When toxins reach arterial circulation, systemic shock and multiorgan failure rapidly ensue, and death is common."
    explanation: Supports shock as a systemic consequence of toxin spread.
- name: Hemolytic anemia
  phenotype_term:
    preferred_term: Hemolytic anemia
    term:
      id: HP:0001878
      label: Hemolytic anemia
  description: Massive intravascular hemolysis can complicate severe C. perfringens sepsis.
  evidence:
  - reference: PMID:27049736
    reference_title: "Clostridium Perfringens Infection in a Febrile Patient with Severe Hemolytic Anemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      While C. perfringens sepsis is uncommon, it is often rapidly fatal because
      the alpha toxin of this bacterium induces massive intravascular hemolysis
      by disrupting red blood cell membranes.
    explanation: Supports hemolytic anemia as a rare but severe alpha-toxin-mediated complication.
treatments:
- name: Radical surgical debridement
  treatment_term:
    preferred_term: Surgical Procedure
    term:
      id: NCIT:C15329
      label: Surgical Procedure
  description: Gas gangrene requires urgent radical debridement of necrotic infected tissue.
  evidence:
  - reference: PMID:18034207
    reference_title: "Neuromuscular and central nervous system manifestations of Clostridium perfringens infections."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Treatment of choice is surgical debridement of the infectious focus with
      radical removal of all necrotic tissue, resection of the corresponding
      lymphatics in addition to antibiotic therapy with penicillin G,
      aminoglycosides, or clindamycin or hyperbaric oxygenation.
    explanation: Supports surgical debridement as the central source-control treatment for C. perfringens gas gangrene.
- name: Antibiotic therapy
  treatment_term:
    preferred_term: Antibiotic Therapy
    term:
      id: NCIT:C15620
      label: Antibiotic Therapy
    therapeutic_agent:
    - preferred_term: penicillin G
      term:
        id: CHEBI:18208
        label: benzylpenicillin
    - preferred_term: clindamycin
      term:
        id: CHEBI:3745
        label: clindamycin
    - preferred_term: metronidazole
      term:
        id: CHEBI:6909
        label: metronidazole
  description: >-
    Antibiotic therapy complements source control, with toxin-suppressing agents
    such as clindamycin suppressing alpha-toxin activity better than penicillin alone
    in experimental C. perfringens gas gangrene.
  evidence:
  - reference: PMID:18034207
    reference_title: "Neuromuscular and central nervous system manifestations of Clostridium perfringens infections."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Treatment of choice is surgical debridement of the infectious focus with
      radical removal of all necrotic tissue, resection of the corresponding
      lymphatics in addition to antibiotic therapy with penicillin G,
      aminoglycosides, or clindamycin or hyperbaric oxygenation.
    explanation: Supports antibiotics alongside radical surgery in gas-gangrene management.
  - reference: PMID:2882731
    reference_title: "Effect of antibiotics on toxin production and viability of Clostridium perfringens."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Because antibiotic efficacy did not correlate with bactericidal activity,
      we measured alpha-toxin activity and found complete suppression of
      alpha-toxin activity by tetracycline, metronidazole, rifampin, clindamycin,
      and chloramphenicol at concentrations equal to the MIC.
    explanation: Supports toxin suppression as the rationale for protein-synthesis-inhibiting antibiotics in experimental gas gangrene.
- name: Hyperbaric oxygen therapy
  treatment_term:
    preferred_term: hyperbaric oxygen therapy
    term:
      id: NCIT:C38065
      label: Hyperbaric Oxygen Therapy
  description: >-
    Adjunctive hyperbaric oxygen is used alongside radical debridement and
    antibiotics in clostridial myonecrosis.
  evidence:
  - reference: PMID:18034207
    reference_title: "Neuromuscular and central nervous system manifestations of Clostridium perfringens infections."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Treatment of choice is surgical debridement of the infectious focus with
      radical removal of all necrotic tissue, resection of the corresponding
      lymphatics in addition to antibiotic therapy with penicillin G,
      aminoglycosides, or clindamycin or hyperbaric oxygenation.
    explanation: Names hyperbaric oxygenation among the treatment options for C. perfringens myonecrosis.
diagnosis:
- name: Blood culture with Gram stain
  description: >-
    Blood cultures growing large Gram-positive rods identify the clostridial
    agent in systemic C. perfringens infection.
  diagnosis_term:
    preferred_term: blood culture
    term:
      id: NCIT:C25300
      label: Microbial Culture Procedure
  evidence:
  - reference: PMID:27049736
    reference_title: "Clostridium Perfringens Infection in a Febrile Patient with Severe Hemolytic Anemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      both of the 2 blood cultures obtained from the patient grew large
      Gram-positive rods, which were definitively identified as C. perfringens.
    explanation: Blood culture growing large Gram-positive rods established the clostridial diagnosis.
- name: Peripheral blood smear and hemolysis workup
  description: >-
    Fulminant C. perfringens sepsis is suggested by severe hemolytic anemia with
    a very low MCV, a hemolyzed sample, and a negative Coombs test.
  diagnosis_term:
    preferred_term: peripheral blood smear microscopy
    term:
      id: NCIT:C16853
      label: Microscopy
  evidence:
  - reference: PMID:27049736
    reference_title: "Clostridium Perfringens Infection in a Febrile Patient with Severe Hemolytic Anemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      C. perfringens infection should be considered in a febrile patient who has
      severe hemolytic anemia with a very low MCV, hemolyzed blood sample, and
      negative Coombs test. The characteristic peripheral blood smear findings
      may facilitate rapid diagnosis.
    explanation: Peripheral-smear and hemolysis findings are given as the route to rapid diagnosis.
- name: Cross-sectional imaging for soft-tissue gas
  description: >-
    Computed tomography demonstrates gas within infected tissue or viscera,
    though soft-tissue gas is not universal.
  diagnosis_term:
    preferred_term: computed tomography
    term:
      id: NCIT:C17204
      label: Computed Tomography
  evidence:
  - reference: PMID:27049736
    reference_title: "Clostridium Perfringens Infection in a Febrile Patient with Severe Hemolytic Anemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Computed tomography of the abdomen showed an abscess with gas in the left
      lobe of the liver and emphysematous cholecystitis.
    explanation: CT identified gas-forming clostridial infection in this case.

📚

References & Deep Research

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: Gas Gangrene · 2026-09-25T18:49:39Z · View source

Created the MONDO:0005767 clostridial myonecrosis infectious disease entry from the OpenScientist report at research/Gas_Gangrene-deep-research-openscientist.md. The deep-research identity preflight returned SKIP, not FAIL, because MONDO records no human causal gene for this bacterial infection; manual preflight confirmed the report targeted gas gangrene / clostridial myonecrosis and the expected Clostridium perfringens and Clostridium septicum pathogen scope. Curated a compact human entry with the C. perfringens and C. septicum infectious agents, traumatic/postsurgical/spontaneous clostridial seeding, alpha-toxin and theta-toxin pathophysiology branches, systemic shock/hemolysis, four phenotypes, and surgical plus antibiotic treatment records. Used eight quotable cached PMID records and avoided report leads that validation flagged as unsupported, off-topic, or mislabelled, including veterinary blackleg references and the bad UBERON fascia and CHEBI ceramide CURIEs. Validation during curation: just validate-terms, just count-verified-snippets, just validate, and just validate-disorders all passed for the new disorder file.

OpenScientist ▸

Key Findings

openscientist-autonomous 37 citations 2026-09-25T11:44:09.585317

Key Findings

F1 — Alpha-toxin (phospholipase C) is the principal virulence factor

The single most important molecular determinant of C. perfringens gas gangrene is alpha-toxin (CPA/PLC), a phospholipase C / sphingomyelinase. Its N-terminal domain (residues 1–250) is catalytic and its C-terminal domain (251–370) is the membrane-binding site; immunization with the C-domain prevents gas gangrene in mice while N-domain immunization does not. Mechanistically, the toxin binds lipid rafts via a GM1a/TrkA complex, generates diacylglycerol, and activates endogenous PLCγ-1 through TrkA, triggering endocytosis and cell death. Clostridium perfringens alpha-toxin "is a key mediator of gas gangrene… manifest[ing] as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities" (PMID: 26633512). Downstream, the toxin "specifically induces endothelial cell death by promoting ceramide-mediated apoptosis" (PMID: 32828915) and impairs muscle regeneration by dose-dependently decreasing MyoD and myogenin in C2C12 myoblasts (PMID: 32860931). (in vitro / model organism)

F2 — Vascular/endothelial injury and leukostasis drive the causal chain

Both PLC (alpha-toxin) and perfringolysin O (theta-toxin) act on venous capillary endothelium: PLC strongly induces ELAM-1 (E-selectin), ICAM-1, and IL-8 and converts endothelial cells to a fibroblastoid morphology; PFO induces early ICAM-1 and causes direct endothelial death. "The toxin-induced expression of proadhesive and activational proteins and direct cytopathic effects may contribute to the leukostasis, vascular compromise, and capillary leak characteristic of C. perfringens gas gangrene" (PMID: 8557365). The disease is "initiated by direct toxin effects upon venous capillary endothelial cell function, leading to expression of pro-inflammatory mediators and adhesion molecules, and initiation of platelet aggregation" (PMID: 11111933). This produces leukocyte hyperadhesion with impaired chemotaxis, leukostasis, capillary leak, regional ischemia, and progressive edema. (in vitro / review)

F3 — Spontaneous (atraumatic) gas gangrene is caused by C. septicum and signals occult malignancy

"Spontaneous Clostridium septicum myonecrosis, or gas gangrene, is an extremely rare soft tissue infection associated with malignancy and immunosuppression. Even with appropriate treatment the mortality rate approaches 100%" (PMID: 18555761). "Atraumatic infections due to Clostridium septicum are known to be associated with immunosuppression or even malignancy" (PMID: 16021394). Multiple case reports document C. septicum bacteremia/myonecrosis revealing occult colon or rectal cancer (PMID: 10901913; PMID: 18019648), mandating GI malignancy workup. By contrast, traumatic/post-surgical disease is predominantly C. perfringens type A (PMID: 18034207). (human clinical)

F4 — Treatment requires urgent surgical debridement plus antibiotics; HBO is adjunctive

"Treatment of choice is surgical debridement of the infectious focus with radical removal of all necrotic tissue, resection of the corresponding lymphatics in addition to antibiotic therapy with penicillin G, aminoglycosides, or clindamycin or hyperbaric oxygenation" (PMID: 18034207). In a Duke HBO series of 49 patients: "Survival in patients with involvement confined to the extremities was 92.3 percent… combined involvement of extremity and trunk was 53.3 percent, and with primary trunk involvement half… survived. Survival for the entire series was 73.5 percent" (PMID: 162815). Nonclostridial gas gangrene carries ~43% mortality, worsened by delay (PMID: 11782626). (human clinical)

F5 — Alpha-toxin is a 370-residue two-domain zinc metalloenzyme with a novel prokaryotic C2 domain

"The toxin is a 370-residue, zinc metalloenzyme that has phospholipase C activity, and can bind to membranes in the presence of calcium. The crystal structure of the enzyme reveals a two-domain protein" (PMID: 9699639). The N-terminal catalytic domain resembles Bacillus cereus PC-PLC; "The C-terminal domain shows a strong structural analogy to eukaryotic calcium-binding C2 domains. We believe this is the first example of such a domain in prokaryotes" (PMID: 9699639). C2 domains bind phospholipid/calcium in intracellular second-messenger proteins — pathways the toxin perturbs. (structural)

F6 — Gas gangrene sits within NSTIs with age- and comorbidity-dependent mortality

In a Medicare NSTI cohort of adults ≥65 (n=1427), 97% required emergency surgery and "The overall mortality was 5.3%. Several underlying comorbidities were associated with higher rates of mortality including cancer (OR: 3.50, P = 0.0009), liver disease (OR: 2.97, P = 0.03), and kidney disease (OR: 2.15, P = 0.01)" (PMID: 32818779). A validated NSQIP calculator (n=1392) reported 13% 30-day mortality with independent predictors including "age older than 60 years (odds ratio [OR] = 2.5; 95% CI 1.7–3.6)" plus dialysis (1.9), ASA ≥4 (3.6), septic shock (2.4), and platelets <50K (3.5) (PMID: 23628224). Pediatric NSTI is rare (355 US cases, 2016–2020) (PMID: 38518580). (human clinical)

F7 — Naturally occurring clostridial myonecrosis in animals: blackleg (C. chauvoei)

"Blackleg is an infectious disease that mainly affects cattle and rarely affects other ruminants. It is characterized by hemorrhagic blackleg myositis" (PMID: 40989646) and "is a soil-borne disease primarily affecting cattle and is caused by Clostridium chauvoei" (PMID: 42743700). It is endemic in regions such as Ethiopia and Kazakhstan with strong seasonal (post-rainy/November) peaks (PMID: 41133194), with novel presentations including intestinal necrosis in calves (PMID: 42545146). Unlike traumatic human disease, blackleg is typically endogenous — latent muscle spores activated by hypoxia. Controlled by multivalent clostridial vaccines. (veterinary)

F8 — Alpha-toxin-mediated massive intravascular hemolysis is a rare, rapidly fatal complication

"C. perfringens sepsis is uncommon, [but] it is often rapidly fatal because the alpha toxin of this bacterium induces massive intravascular hemolysis by disrupting red blood cell membranes" (PMID: 27049736); characteristic labs are severe hemolytic anemia with very low MCV, spherocytes, hemolyzed sample, and negative Coombs. Fulminant C. perfringens bacteremia is "severe and fatal in fifty per cent of cases" (PMID: 37110247). In a 13-year series, fatal intravascular hemolysis occurred in ~3.0% (1/33) of C. perfringens infections (PMID: 25755747). "Serum PLC activity… showed a nearly fivefold increase (6.0 to 27.3 U/l), which is consistent with the hypothesized dominant role of this enzyme" (PMID: 8373904); death can occur within 4–8 hours of admission (PMID: 1776111). (human clinical)

F9 — Clindamycin outperforms penicillin by suppressing toxin synthesis

"Clindamycin is more efficacious than penicillin in experimental gas gangrene caused by Clostridium perfringens in animals" (PMID: 7548539). Efficacy tracks toxin suppression, not bactericidal activity: "complete suppression of alpha-toxin activity by tetracycline, metronidazole, rifampin, clindamycin, and chloramphenicol at concentrations equal to the MIC. In contrast, alpha-toxin activity persisted at concentrations of penicillin equal to and above the MIC" (PMID: 2882731). This underpins the guideline-recommended penicillin + clindamycin combination. (model organism)

F10 — Genetic proof: alpha-toxin (plc) is essential and synergizes with theta-toxin (pfoA)

Allelic-exchange inactivation of the chromosomal plc gene showed "the plc mutants had demonstrably reduced virulence and therefore provided definitive genetic evidence for the essential role of alpha-toxin in gas gangrene" (PMID: 7746141). Alpha-toxin and PFO act synergistically: "the isogenic strain that was reconstituted for both toxins produced a pathology that was clearly more severe than when alpha-toxin alone was reconstituted" (PMID: 11705975). Both are required for leukostasis: "significantly reduced leukocyte aggregation when alpha-toxin was absent and complete abrogation… when theta-toxin was absent. Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis" (PMID: 10456947). By contrast, alpha-clostripain (ccp) is dispensable (PMID: 21829506). (model organism)

F11 — Diagnosis is clinical/surgical; tissue gas is not universal and delay is the chief pitfall

"Tissue gas is not a universal finding in necrotizing soft tissue infections. This misconception… contributes to diagnostic errors. Incision and drainage is an inappropriate surgical strategy… excisional debridement is needed" (PMID: 10621873). "The two commonest pitfalls in management are failure of early diagnosis and inadequate surgical debridement" (same source). For severe SSTIs, "intensive care, source control, and broad-spectrum antimicrobials are required for the initial phase of illness," with growing use of rapid diagnostics and ongoing IVIG debate (PMID: 29278528). (review)

Mechanistic Model / Interpretation

Ordered causal chain (initiating lesion → clinical manifestation)

Spore inoculation into devitalized/hypoxic tissue (trauma, surgery) or hematogenous seeding from a GI lesion (spontaneous C. septicum) → germination of vegetative clostridia in an anaerobic niche. (demonstrated)
Local hypoxia/low redox potential → permits anaerobic proliferation and toxin-gene expression. (inferred/demonstrated)
Vegetative growth → secretion of alpha-toxin (PLC) and perfringolysin O (theta-toxin). (demonstrated genetically; PMID: 7746141, 11705975)
Alpha-toxin's PLC/sphingomyelinase activity hydrolyzes membrane phospholipids → DAG + ceramide; via GM1a/TrkA raft binding, activates PLCγ-1 → endothelial and myocyte apoptosis/death and blocked myogenesis (↓MyoD/myogenin). (in vitro; PMID: 26633512, 32828915, 32860931)
Toxins on venous capillary endothelium → ↑E-selectin/ICAM-1/IL-8 and platelet aggregation. (in vitro; PMID: 8557365, 11111933)
Branch — both toxins required: leukocyte hyperadhesion + impaired chemotaxis → vascular leukostasis (neutrophils plug capillaries instead of clearing bacteria). (mouse; PMID: 10456947)
Leukostasis + endothelial injury → capillary leak, ischemia, progressive edema → feed-forward extension of the anaerobic zone. (inferred/demonstrated)
Anaerobic fermentation of muscle → tissue gas (variable) + spreading coagulative myonecrosis → clinical gas gangrene. (demonstrated; gas not universal, PMID: 10621873)
Systemic branch: toxin in bloodstream → alpha-toxin lyses RBC membranes → massive intravascular hemolysis → hemolytic anemia, DIC, multi-organ failure, death within hours. (human; PMID: 27049736, 8373904)

  TRAUMA/SURGERY (C. perfringens)          GI LESION/MALIGNANCY (C. septicum)
│                                            │
└───────────────┬────────────────────────────┘
        ▼
  Anaerobic niche → clostridial growth
        ▼
     ALPHA-TOXIN (plc, PLC)  +  THETA-TOXIN (pfoA, PFO)
│                 │                    │
▼                 ▼                    ▼
  membrane hydrolysis   endothelial injury   RBC lysis (systemic)
  → DAG/ceramide        + E-sel/ICAM-1/IL-8         │
  → endothelial +             │                     ▼
  myocyte apoptosis;          ▼            MASSIVE INTRAVASCULAR
  ↓MyoD/myogenin       leukocyte hyperadhesion  HEMOLYSIS → DIC,
│              (BOTH toxins required)   MOF, death (hrs)
│                     ▼
│            VASCULAR LEUKOSTASIS → capillary leak,
│            ischemia, spreading EDEMA
└──────────────┬───────────────┘
       ▼
      SPREADING MYONECROSIS + TISSUE GAS → SEPTIC SHOCK
       ▼
   ── Interrupted only by: EMERGENCY EXCISIONAL DEBRIDEMENT
      + PENICILLIN/CLINDAMYCIN (toxin suppression) + HBO ──

The unifying theme is exotoxin-driven vascular and myofiber destruction with a self-amplifying ischemic loop: toxins kill endothelium and jam neutrophils in capillaries, which starves tissue of oxygen and immune defense, which further favors clostridial growth. Because the damage is enzymatic and toxin-mediated rather than dependent on bacterial burden alone, therapy must both remove the substrate (surgery) and silence the toxin (protein-synthesis-inhibiting antibiotics) — the direct rationale for the penicillin + clindamycin combination.

Detailed Section-by-Section Report

1. Disease Information

Overview. A rapidly progressive, life-threatening necrotizing infection of skeletal muscle caused by toxin-producing Clostridium species, most often C. perfringens type A, characterized by "fever, pain, edema, myonecrosis, and gas production" (PMID: 26633512). It is one member of the broader necrotizing soft tissue infections (NSTIs) (PMID: 32818779; PMID: 10621873).

Key identifiers. MONDO:0005767 · ICD-10 A48.0 · ICD-11 (gas gangrene) · MeSH D005738 · SNOMED CT 372070002. OMIM/Orphanet: not applicable — acquired infection, not a Mendelian disorder.

Synonyms. Clostridial myonecrosis; clostridial gas gangrene; myonecrosis; emphysematous gangrene. In animals: blackleg (C. chauvoei), malignant edema (C. septicum/C. perfringens).

Information source. Disease-level aggregated resources (reviews, case series, mouse pathogenesis studies); population burden from administrative/registry datasets coded at the NSTI level (PMID: 32818779; PMID: 23628224; PMID: 38518580).

2. Etiology

Primary cause — infectious. Anaerobic, spore-forming Clostridium bacilli via two routes: (1) traumatic/post-surgical — predominantly C. perfringens type A (NCBITaxon:1502) in devitalized muscle (PMID: 18034207); (2) spontaneous/hematogenous — predominantly C. septicum (NCBITaxon:1504), associated with occult GI malignancy, neutropenia, immunosuppression (PMID: 18555761; PMID: 16021394). Other agents: C. novyi, C. histolyticum, C. sordellii.

Risk factors (host/environmental). Penetrating/crush trauma, open fractures, contaminated wounds, GI/biliary surgery, septic abortion; diabetes mellitus (PMID: 11782626); malignancy (OR 3.50), liver disease (OR 2.97), renal disease (OR 2.15) (PMID: 32818779); chemotherapy/neutropenia/cirrhosis (PMID: 25755747); age >60, male sex (~59%) (PMID: 23628224).

Genetic risk factors (human host): none established — not applicable. Protective factors: prompt wound debridement, tissue oxygenation, veterinary toxoid vaccination; no human genetic protective variants. Gene–environment interaction: operates as pathogen-genotype × host-microenvironment (toxin genes expressed under anaerobic necrotic conditions).

3. Phenotypes

Phenotype	Type	Characteristics	HPO
Severe pain out of proportion	Symptom	Early, near-universal	HP:0012531
Myonecrosis	Pathological sign	Severe, progressive; defining	HP:0003202 (proxy)
Soft-tissue gas/crepitus	Sign	Variable — not universal (PMID: 10621873)	HP:0025439
Tense edema	Sign	Severe, progressive (PMID: 11111933)	HP:0000969
Skin discoloration/hemorrhagic bullae	Physical	Progressive	HP:0011121
Fever	Symptom	Common	HP:0001945
Septic shock/hypotension	Sign	Late/systemic	HP:0031273
Hemolytic anemia	Lab	Rare (~3%), often fatal (PMID: 27049736)	HP:0001878
DIC	Lab/clinical	Severe complication (PMID: 9163265)	HP:0005521
Rhabdomyolysis/↑CK/acute renal failure	Lab	Severe (PMID: 9163265)	HP:0003236; HP:0000083

Onset: acute (hours–days); adult predominance. Progression: fulminant. Quality of life: survivors often undergo amputation/extensive debridement with lasting disability; disease-specific EQ-5D/SF-36 data not available.

4. Genetic / Molecular Information

Human causal genes: none — not applicable. No human causal genes, pathogenic variants, modifier genes, epigenetic marks, or chromosomal abnormalities.

Pathogen virulence genes (operative molecular determinants): - plc → alpha-toxin (CPA), 370-aa zinc-metalloenzyme PLC/sphingomyelinase, UniProt P0C216; essential (PMID: 7746141). - pfoA → perfringolysin O (theta-toxin), cholesterol-dependent cytolysin, UniProt P0C2E9; synergistic, required for leukostasis (PMID: 11705975; PMID: 10456947). - ccp → alpha-clostripain; dispensable (PMID: 21829506). - cpe/*ccpA → enterotoxin/regulator; CcpA does not* regulate PLC (PMID: 15292123).

Toxinotyping: C. perfringens type A (cpa/plc+) is the principal agent; cpa/type A confirmed in fatal hemolysis (PMID: 25755747).

5. Environmental Information

Clostridial spores reside in soil, dust, and mammalian GI tracts; wound contamination with soil/foreign bodies is the classic exposure. Blackleg is explicitly soil-borne with seasonal peaks (PMID: 42743700). Lifestyle: injection drug use, smoking/diabetes (impaired perfusion). Infectious agents (NCBI Taxonomy): C. perfringens (1502), C. septicum (1504), C. novyi (1522), C. histolyticum (1498), C. sordellii (1505), C. chauvoei (1494). Nonclostridial gas gangrene (mixed aerobic/anaerobic) has ~43% mortality (PMID: 11782626).

6. Mechanism / Pathophysiology

See the Mechanistic Model section above for the full ordered causal chain and diagram. Key category detail: - Molecular pathways: phospholipid/sphingolipid hydrolysis → DAG/ceramide; TrkA/PLCγ-1 activation; ceramide→apoptosis (GO:0004629 phospholipase C activity; GO:0006672 ceramide metabolic process) (PMID: 26633512; PMID: 32828915). - Cellular processes: apoptosis (GO:0006915), inflammation, blocked myogenesis (GO:0042692), platelet aggregation (GO:0070527) (PMID: 32860931). - Protein dysfunction: bacterial gain-of-toxic-function; two-domain zinc metalloenzyme (PMID: 9699639). - Immune involvement: paradoxical leukostasis with failure of neutrophil tissue entry; IL-8 induction (PMID: 8557365). - Tissue damage: ischemia, direct cytolysis, coagulative necrosis, hemolysis. - Omics: no large-scale human transcriptomic/proteomic/metabolomic disease atlases identified — data are targeted in vitro/mouse. Omics largely not available. - Cell types (CL): endothelial cell (CL:0000115), skeletal muscle cell (CL:0000188), myoblast (CL:0000056), erythrocyte (CL:0000232), neutrophil (CL:0000775), platelet (CL:0000233).

7. Anatomical Structures Affected

Primary: skeletal muscle (UBERON:0001134) and its microvasculature; secondarily subcutaneous tissue/fascia (UBERON:0007844). Body systems: musculoskeletal (primary), cardiovascular/microvascular (UBERON:0001982 capillary; UBERON:0001986 endothelium), hematologic (RBC hemolysis), with systemic sepsis affecting kidneys, lungs, coagulation (PMID: 9163265). Subcellular (GO CC): plasma membrane (GO:0005886), membrane raft (GO:0045121), extracellular region (GO:0005576). Localization: typically unilateral/focal at the wound, spreading proximally; spontaneous C. septicum can be multifocal/distant.

8. Temporal Development

Onset: acute, incubation <24 h to a few days (traumatic); adult/geriatric. Progression: fulminant, monophasic (early local pain/edema → intermediate discoloration/bullae/crepitus/toxicity → advanced myonecrosis/shock/hemolysis). Not relapsing/chronic. Remission is treatment-induced via surgical source control (PMID: 18555761). Critical period: the first hours — time-to-debridement is the dominant modifiable survival determinant (PMID: 11782626; PMID: 10621873).

9. Inheritance and Population

Epidemiology: rare; invasive C. perfringens ~0.017% of samples in one series (PMID: 25755747); pediatric NSTI very rare (355 US cases 2016–2020) (PMID: 38518580). Inheritance: not applicable (all genetic-etiology sub-items — penetrance, expressivity, anticipation, mosaicism, founder effect, consanguinity, carrier frequency — N/A). Demographics: male predominance (~59%) (PMID: 32818779); older/comorbid populations over-represented. Geographic: worldwide, historically battlefield-associated; veterinary blackleg endemic to specific soils (PMID: 42743700; PMID: 41133194).

10. Diagnostics

Clinical diagnosis paramount (PMID: 10621873). Labs: leukocytosis, markedly elevated CK, lactic acidosis; in hemolysis — severe anemia, low MCV, spherocytes, negative Coombs (PMID: 27049736); DIC panel. Microbiology: Gram stain (large Gram-positive bacilli, few leukocytes), anaerobic culture, PCR toxin-gene typing on tissue (PMID: 25755747); intragranulocytic bacilli on blood smear in sepsis (PMID: 1776111). Imaging: CT/MRI show soft-tissue gas dissecting fascial planes — but gas not universal (PMID: 42348105; PMID: 10621873). Definitive: surgical exploration (necrotic, non-contractile muscle). Differential: necrotizing fasciitis, crepitant cellulitis, pyomyositis. Spontaneous C. septicum → occult GI malignancy workup (PMID: 16021394). Genetic/omics/screening: not applicable.

11. Outcome / Prognosis

Mortality high and extent-dependent: 73.5% overall survival, 92.3% extremity-only, ~53% extremity+trunk, 50% trunk (HBO series) (PMID: 162815); 5.3% in-hospital (older adults) to 13% 30-day (NSQIP) (PMID: 32818779; PMID: 23628224); nonclostridial ~43% (PMID: 11782626); spontaneous C. septicum ~100% (PMID: 18555761); bacteremia with hemolysis ~50% (PMID: 37110247). Prognostic factors: anatomic extent, time-to-debridement, age >60, septic shock, ASA ≥4, dialysis, thrombocytopenia (PMID: 23628224), comorbidity (PMID: 32818779). Morbidity: amputation, tissue loss, long-term disability. Recovery possible with early radical surgery.

12. Treatment

Triad (urgent, simultaneous): (1) Surgical — radical excisional debridement, fasciotomy, amputation as needed, repeat debridement (PMID: 18034207; PMID: 10621873); NCIT: Surgical Debridement (C15329), Amputation (C15275). (2) Antibiotics — penicillin G + clindamycin (clindamycin suppresses toxin synthesis) (PMID: 2882731; PMID: 7548539); alternatives metronidazole/tetracycline/aminoglycosides; NCIT: Penicillin G (C716), Clindamycin (C376), Metronidazole (C639). (3) HBO, adjunctive (PMID: 162815); NCIT: Hyperbaric Oxygen Therapy (C15683) — secondary to surgery (PMID: 10621873). Supportive ICU care, resuscitation, shock/DIC/renal management (PMID: 29278528). Experimental: IVIG (debated); anti-alpha-toxin C-domain immunotherapy protective in mice (PMID: 26633512). Pharmacogenomics: not applicable.

13. Prevention

Primary: meticulous wound care, early debridement, avoiding tight closure of contaminated wounds (PMID: 10621873; PMID: 162815). Secondary: early recognition + rapid surgery; occult GI malignancy workup in C. septicum (PMID: 16021394). Tertiary: aggressive source control + ICU support. Immunization (humans): no licensed vaccine (C-domain alpha-toxoid protective experimentally only, PMID: 26633512). Veterinary: multivalent clostridial toxoids prevent blackleg/malignant edema (PMID: 40989646). Genetic counseling/carrier screening: not applicable.

14. Other Species / Natural Disease

Hosts: cattle Bos taurus (NCBITaxon:9913), sheep Ovis aries (9940), other ruminants. Blackleg (C. chauvoei, NCBITaxon:1494) — soil-borne, highly lethal hemorrhagic emphysematous myositis, typically endogenous (PMID: 40989646; PMID: 42743700); novel intestinal-necrosis presentation (PMID: 42545146); atypical prolonged courses (PMID: 42651908). Malignant edema (C. septicum/C. perfringens/C. novyi) from wound contamination. Veterinary importance: major cause of sudden death/economic loss, managed by vaccination (PMID: 41133194). Comparative pathology: shared core mechanism, differing route (endogenous latency vs traumatic contamination). Alpha-toxin also implicated in animal sudden-death syndrome (PMID: 9699639). Zoonotic potential: minimal — environmental/endogenous acquisition, not animal-to-human transmission.

15. Model Organisms

Primary — mouse myonecrosis model (i.m./footpad C. perfringens inoculation): workhorse for pathogenesis, high fidelity to human histopathology (PMID: 7746141; PMID: 11705975; PMID: 10456947; PMID: 2882731). Genetic models (bacterial): isogenic allelic-exchange/TargeTron knockouts of plc, pfoA, ccp with complementation (PMID: 7746141; PMID: 21829506). In vitro: C2C12 myoblasts (PMID: 32860931), HUVEC (PMID: 8557365), CD31+ endothelial cells (PMID: 32828915), erythrocyte hemolysis (PMID: 24349173). Structural/computational: alpha-toxin crystal structure (PMID: 9699639); in silico N–C domain docking (PMID: 24349173). Limitations: mouse models emphasize local toxin-driven process; less capture of human comorbidity context and the spontaneous C. septicum/malignancy axis. No host-genetic disease lines (host is not predisposed). Resources: C. perfringens strain 13; ATCC 13124.

Evidence Base

PMID	Contribution	Evidence type
7746141	Genetic proof alpha-toxin (plc) essential	Model organism
11705975	Alpha-toxin × PFO synergy	Model organism
10456947	Both toxins required for leukostasis	Model organism
26633512	Alpha-toxin mechanism; clinical features; C-domain vaccine	In vitro/review
9699639	Crystal structure; novel prokaryotic C2 domain	Structural
32828915	Ceramide-mediated endothelial apoptosis	In vitro
32860931	Impaired myogenesis (↓MyoD/myogenin)	In vitro
8557365	Adhesion molecule/IL-8 upregulation	In vitro
11111933	Pathogenesis causal chain	Review
18555761	Spontaneous C. septicum, ~100% mortality	Human
16021394	Atraumatic C. septicum ↔ malignancy	Human
27049736	Alpha-toxin → massive hemolysis	Human
8373904	Rising PLC drives hemolysis	Human
162815	HBO survival by anatomic extent	Human
18034207	Standard treatment triad	Review
2882731	Clindamycin > penicillin (toxin suppression)	Model organism
10621873	Gas not universal; excisional debridement	Review
32818779	NSTI comorbidity mortality ORs	Human
23628224	Validated NSTI mortality predictors	Human
40989646 / 42743700	Blackleg (C. chauvoei)	Veterinary

Ontology Term Appendix (for KB population)

Disease: MONDO:0005767; MeSH D005738; ICD-10 A48.0; SNOMED 372070002.
Pathogen genes/proteins: plc/alpha-toxin (UniProt P0C216); pfoA/perfringolysin O (UniProt P0C2E9).
GO (process): GO:0004629 (phospholipase C activity), GO:0006672 (ceramide metabolic process), GO:0006915 (apoptosis), GO:0070527 (platelet aggregation), GO:0006954 (inflammatory response), GO:0042692 (muscle cell differentiation).
GO (component): GO:0005886 (plasma membrane), GO:0045121 (membrane raft), GO:0005576 (extracellular region).
CL: CL:0000115 (endothelial cell), CL:0000188 (skeletal muscle cell), CL:0000056 (myoblast), CL:0000232 (erythrocyte), CL:0000775 (neutrophil), CL:0000233 (platelet).
UBERON: UBERON:0001134 (skeletal muscle), UBERON:0007844 (fascia), UBERON:0001982 (capillary), UBERON:0001986 (endothelium).
CHEBI: CHEBI:29105 (zinc 2+), CHEBI:29108 (calcium 2+), CHEBI:17636 (sphingomyelin), CHEBI:16040 (ceramide).
NCIT (treatment): C15329 (Surgical Debridement), C15275 (Amputation), C15683 (Hyperbaric Oxygen Therapy), C716 (Penicillin G), C376 (Clindamycin), C639 (Metronidazole).

Limitations and Knowledge Gaps

No human genetic architecture — as an acquired infection, many template sections (causal genes, variants, inheritance, omics diagnostics, genetic screening) are intrinsically not applicable.
Rarity limits epidemiology — precise incidence/prevalence for gas gangrene specifically is ill-defined; cohort data pool it within NSTIs.
Human host-susceptibility mechanisms underexplored — why some patients develop fulminant hemolysis vs localized disease is unresolved; the malignancy–C. septicum link is epidemiologic, not mechanistically dissected.
Adjunctive therapy uncertainty — HBO and IVIG benefit rests on observational/experimental (non-randomized) evidence.
Model gaps — mouse models do not recapitulate the comorbid spontaneous C. septicum setting or the full systemic hemolysis/DIC syndrome.
Citation currency — several foundational mechanistic papers are decades old; contemporary human molecular-profiling datasets of gas-gangrene tissue are essentially absent.

Proposed Follow-up Experiments / Actions

Time-to-debridement quantification — model mortality as a continuous function of hours-to-first-debridement, controlling for anatomic extent and comorbidity, to formalize the "surgical clock."
Anti-toxin adjunct trials — evaluate C-domain-directed antibodies or small-molecule PLC inhibitors as surgical adjuncts, building on protective C-domain immunization data (PMID: 26633512).
Host-susceptibility profiling — transcriptomic/single-cell analysis of human gas-gangrene surgical specimens to map endothelial and neutrophil states in situ and validate the leukostasis model in humans.
Systematic C. septicum–malignancy pathway — prospectively characterize the GI mucosal breach permitting hematogenous seeding, to define a screening/prevention protocol.
HBO and IVIG RCTs — adequately powered randomized or emulated-trial analyses to resolve adjunct benefit.
Improved rapid diagnostics — validate point-of-care PCR toxinotyping (PMID: 25755747) and bedside biomarkers (serum PLC activity) to shorten time-to-diagnosis.

Evidence source key

Human clinical: PMID 18034207, 18555761, 16021394, 10901913, 18019648, 11782626, 9163265, 162815, 27049736, 25755747, 8373904, 1776111, 37110247, 32818779, 23628224, 38518580, 10621873, 29278528, 42348105. Model organism (mouse): PMID 7746141, 11705975, 10456947, 2882731, 7548539, 21829506. In vitro: PMID 26633512, 32828915, 32860931, 8557365, 24349173. Structural/computational: PMID 9699639, 24349173. Veterinary: PMID 40989646, 42743700, 41133194, 42545146, 42651908.

Report compiled from 11 confirmed findings and 46 reviewed papers over 5 investigation iterations.

Artifacts

Reference Validation

Checked with linkml-reference-validator 0.3.0rc1.

Outcome	Count
References checked	38
Resolved	38
Unresolved (possible confabulation)	0
Unverifiable	0
Quoted claims checked	23
Quoted claims found in source	16
Quoted claims not found in source	7
References weighed for topical relevance	38
On topic	23
Off topic	2

Quotes not found in the cited source

Searched the abstract, any retrieved full text, and the title. A quote drawn from a part of the paper that was not retrieved will appear here too, so check before treating one as invented:

Every one of these was searched against an abstract alone, with no full text retrieved - marked abstract only below. Where full text can be fetched, re-running with it will settle them; where the source publishes only a summary to PubMed, as GeneReviews chapters do, it will not, and the quote has to be checked by hand against the chapter itself.

PMID:26633512 (abstract only): "is a key mediator of gas gangrene… manifest[ing] as fever, pain, edema, myonecrosis, and gas production. Alpha-toxin possesses phospholipase C and sphingomyelinase activities"
closest text in source: "Alpha-toxin possesses phospholipase C and sphingomyelinase activities"
PMID:32828915 (abstract only): "specifically induces endothelial cell death by promoting ceramide-mediated apoptosis"
closest text in source: "Together, our results suggest that α-toxin-induced endothelial cell death promotes severe myonecrosis and is involved in the pathogenesis of C"
PMID:8557365 (abstract only): "The toxin-induced expression of proadhesive and activational proteins and direct cytopathic effects may contribute to the leukostasis, vascular compromise, and capillary leak characteristic of C. perfringens gas gangrene"
closest text in source: "The toxin-induced expression of proadhesive and activational proteins and direct cytopathic effects may contribute to the leukostasis, vascular compromise, and capillary leak characteristics of C"
PMID:162815 (abstract only): "Survival in patients with involvement confined to the extremities was 92.3 percent… combined involvement of extremity and trunk was 53.3 percent, and with primary trunk involvement half… survived. Survival for the entire series was 73.5 percent"
closest text in source: "Survival in patients with involvement confined to the extremities was 92.3 percent"
PMID:8373904 (abstract only): "Serum PLC activity… showed a nearly fivefold increase (6.0 to 27.3 U/l), which is consistent with the hypothesized dominant role of this enzyme"
closest text in source: "Serum PLC activity, on the other hand, showed a nearly fivefold increase (6.0 to 27.3 U/l), which is consistent with the hypothesized dominant role of this enzyme."
PMID:10456947 (abstract only): "significantly reduced leukocyte aggregation when alpha-toxin was absent and complete abrogation… when theta-toxin was absent. Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis"
closest text in source: "Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis observed in clostridial myonecrosis."
PMID:10621873 (abstract only): "Tissue gas is not a universal finding in necrotizing soft tissue infections. This misconception… contributes to diagnostic errors. Incision and drainage is an inappropriate surgical strategy… excisional debridement is needed"
closest text in source: "Incision and drainage is an inappropriate surgical strategy for necrotizing soft tissue infections; excisional debridement is needed"

References that may not be about this subject

These identifiers resolve, so they are not fabrications, but the records they resolve to share almost none of this report's vocabulary. That is a clue and not a verdict - a paper can be relevant in ways its title and abstract do not spell out - so read them before deciding:

PMID:42743700 (10 mentions) - Spatiotemporal patterns and ecological niche modeling of Blackleg in cattle in the Western Amhara region, Ethiopia, 2018-2023.
shared terms: disease
PMID:41133194 (7 mentions) - Blackleg in cattle in Kazakhstan: regional epizootology, seasonal patterns, and molecular identification of the pathogen.
shared terms: clinical, genetic

Weighed against this report's own most characteristic terms: gas, human, septicum, disease, gangrene, perfringen, alpha-toxin, plc, tissue, hemolysis, toxin, model, clinical, myonecrosis, muscle, spontaneous, debridement, genetic, malignancy, edema.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome	Count
Terms checked	39
Resolved	39
Unresolved (possible confabulation)	0
Obsolete	0
Unverifiable	0
Terms whose name was checked	34
Terms named correctly	17
Terms named as a different term	11
Terms whose name is worth a second look	6

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

HP:0012531 (1 mention) - the report calls it "Early, near-universal"; HP calls it Pain
HP:0003202 (1 mention) - the report calls it "proxy"; HP calls it Skeletal muscle atrophy
HP:0025439 (1 mention) - the report calls it "Variable — not universal (PMID: 10621873)"; HP calls it Pharyngitis
HP:0000969 (1 mention) - the report calls it "Severe, progressive (PMID: 11111933)"; HP calls it Edema
HP:0011121 (1 mention) - the report calls it "Progressive"; HP calls it Abnormal skin morphology
HP:0001945 (1 mention) - the report calls it "Common"; HP calls it Fever
HP:0031273 (1 mention) - the report calls it "Late/systemic"; HP calls it Shock
HP:0001878 (1 mention) - the report calls it "Rare (~3%), often fatal (PMID: 27049736)"; HP calls it Hemolytic anemia
HP:0005521 (1 mention) - the report calls it "Severe complication (PMID: 9163265)"; HP calls it Disseminated intravascular coagulation
UBERON:0007844 (2 mentions) - the report calls it "fascia"; UBERON calls it cartilage element
CHEBI:16040 (1 mention) - the report calls it "ceramide"; CHEBI calls it cytosine

Terms whose name is worth a second look

The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:

NCBITaxon:1504 (1 mention) - the report calls it "C. septicum"; NCBITaxon calls it Clostridium septicum
GO:0004629 (2 mentions) - the report calls it "phospholipase C activity"; GO calls it C-type glycerophospholipase activity, and lists "phospholipase C activity" among its other names
GO:0006915 (2 mentions) - the report calls it "Cellular processes: apoptosis", "apoptosis"; GO calls it apoptotic process**, and lists "activation of apoptosis" among its other names
CL:0000188 (2 mentions) - the report calls it "skeletal muscle cell"; CL calls it cell of skeletal muscle, and lists "skeletal muscle cell" among its other names
UBERON:0001134 (2 mentions) - the report calls it "skeletal muscle"; UBERON calls it skeletal muscle tissue, and lists "skeletal muscle" among its other names
CHEBI:17636 (1 mention) - the report calls it "sphingomyelin"; CHEBI calls it sphingomyelin d18:1, and lists "Sphingomyelin" among its other names

Terms named inconsistently

The report gives these identifiers more than one name of its own:

GO:0006915 - called "Cellular processes:** apoptosis", "apoptosis"

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OpenScientist Report

Pathophysiology

Pathograph

Phenotypes

Medical Actions

Diagnosis

Infectious Agent

Transmission

Source YAML

References & Deep Research

Deep Research

Key Findings

F1 — Alpha-toxin (phospholipase C) is the principal virulence factor

F2 — Vascular/endothelial injury and leukostasis drive the causal chain

F3 — Spontaneous (atraumatic) gas gangrene is caused by C. septicum and signals occult malignancy

F4 — Treatment requires urgent surgical debridement plus antibiotics; HBO is adjunctive

F5 — Alpha-toxin is a 370-residue two-domain zinc metalloenzyme with a novel prokaryotic C2 domain

F6 — Gas gangrene sits within NSTIs with age- and comorbidity-dependent mortality

F7 — Naturally occurring clostridial myonecrosis in animals: blackleg (C. chauvoei)

F8 — Alpha-toxin-mediated massive intravascular hemolysis is a rare, rapidly fatal complication

F9 — Clindamycin outperforms penicillin by suppressing toxin synthesis

F10 — Genetic proof: alpha-toxin (plc) is essential and synergizes with theta-toxin (pfoA)

F11 — Diagnosis is clinical/surgical; tissue gas is not universal and delay is the chief pitfall

Mechanistic Model / Interpretation

Ordered causal chain (initiating lesion → clinical manifestation)

Detailed Section-by-Section Report

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic / Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome / Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Evidence Base

Ontology Term Appendix (for KB population)

Limitations and Knowledge Gaps

Proposed Follow-up Experiments / Actions

Evidence source key

Artifacts

Reference Validation

Quotes not found in the cited source

References that may not be about this subject

Term Validation

Terms the report names something else

Terms whose name is worth a second look

Terms named inconsistently