data/rag/knowledge_base/Erysipelothrix/genus.json

{
  "schema_version": "1.0",
  "level": "genus",
  "genus": "Erysipelothrix",

  "overview": {
    "short": "Erysipelothrix species are Gram-positive, facultatively anaerobic, non-spore-forming short rods commonly associated with zoonotic exposure.",
    "clinical_context": "Most notably associated with erysipeloid infections following occupational exposure to animals, fish, or animal products."
  },

  "expected_fields": {
    "Gram Stain": "Positive",
    "Shape": "Short Rods",
    "Motility": "Negative",
    "Capsule": "Negative",
    "Spore Formation": "Negative",
    "Haemolysis": "Variable",
    "Haemolysis Type": "Variable",
    "Media Grown On": [
      "Blood Agar"
    ],
    "Colony Morphology": [
      "Small",
      "Grey",
      "Translucent",
      "Smooth"
    ],
    "Oxygen Requirement": "Facultative Anaerobe",
    "Growth Temperature": "20//42",
    "Catalase": "Negative",
    "Oxidase": "Negative",
    "Indole": "Negative",
    "Urease": "Negative",
    "Citrate": "Negative",
    "Methyl Red": "Positive",
    "VP": "Negative",
    "H2S": "Positive",
    "DNase": "Negative",
    "ONPG": "Negative",
    "Coagulase": "Negative",
    "Gelatin Hydrolysis": "Negative",
    "Esculin Hydrolysis": "Negative",
    "Nitrate Reduction": "Negative",
    "NaCl Tolerant (>=6%)": "Negative",
    "Lipase Test": "Negative",
    "Lysine Decarboxylase": "Negative",
    "Ornithine Decarboxylase": "Negative",
    "Ornitihine Decarboxylase": "Negative",
    "Arginine dihydrolase": "Negative",
    "Glucose Fermentation": "Positive",
    "Lactose Fermentation": "Negative",
    "Sucrose Fermentation": "Variable",
    "Maltose Fermentation": "Negative",
    "Mannitol Fermentation": "Negative",
    "Sorbitol Fermentation": "Negative",
    "Xylose Fermentation": "Negative",
    "Rhamnose Fermentation": "Negative",
    "Arabinose Fermentation": "Negative",
    "Raffinose Fermentation": "Negative",
    "Trehalose Fermentation": "Negative",
    "Inositol Fermentation": "Negative",
    "Gas Production": "Negative",
    "TSI Pattern": "Unknown",
    "Colony Pattern": "Unknown",
    "Pigment": "None",
    "Motility Type": "None"
  },

  "field_notes": {
    "H2S": "Distinctive H2S production on TSI or iron-containing media helps differentiate Erysipelothrix from other Gram-positive rods.",
    "Catalase": "Catalase-negative, distinguishing it from many Gram-positive rods.",
    "Haemolysis": "May be weak or variable; not a reliable primary discriminator."
  },

  "key_differentiators": [
    {
      "field": "H2S",
      "expected": "Positive",
      "distinguishes_from": ["Listeria", "Corynebacterium"],
      "notes": "Rare H2S production among Gram-positive rods."
    },
    {
      "field": "Catalase",
      "expected": "Negative",
      "distinguishes_from": ["Listeria"],
      "notes": "Separates Erysipelothrix from catalase-positive short rods."
    }
  ],

  "common_confusions": [
    {
      "genus": "Listeria",
      "reason": "Shared short rod morphology and facultative anaerobic growth."
    },
    {
      "genus": "Corynebacterium",
      "reason": "Gram-positive rod morphology with skin-associated isolates."
    }
  ],

  "when_to_question_identification": [
    "Catalase positivity argues against Erysipelothrix.",
    "Motility suggests Listeria.",
    "Absence of H2S production should prompt reconsideration."
  ],

  "recommended_next_tests": [
    {
      "test": "H2S detection on TSI or iron-containing media",
      "reason": "Key genus-level discriminator.",
      "api_kit": "API Coryne"
    },
    {
      "test": "Motility testing",
      "reason": "Non-motility helps exclude Listeria.",
      "api_kit": "Manual wet mount"
    },
    {
      "test": "MALDI-TOF MS",
      "reason": "Definitive identification and species-level resolution.",
      "api_kit": "Not applicable"
    }
  ],

  "supported_species": [
    "rhusiopathiae",
    "tonsillarum"
  ]
}