data/rag/knowledge_base/Cardiobacterium/hominis.json

{
  "schema_version": "1.0",
  "level": "species",
  "genus": "Cardiobacterium",
  "species": "hominis",

  "overview": {
    "short": "Cardiobacterium hominis is a fastidious Gram-negative, facultatively anaerobic rod in the HACEK group, classically linked to subacute infective endocarditis.",
    "clinical_context": "Often isolated from blood cultures in endocarditis; growth may be slow and require enriched media (e.g., chocolate agar) and prolonged incubation."
  },

  "expected_fields": {
    "Gram Stain": "Negative",
    "Shape": "Rods",
    "Motility": "Negative",
    "Capsule": "Negative",
    "Spore Formation": "Negative",
    "Haemolysis": "Negative",
    "Haemolysis Type": "None",
    "Media Grown On": [
      "Blood Agar",
      "Chocolate Agar"
    ],
    "Colony Morphology": [
      "Small",
      "Smooth",
      "Grey"
    ],
    "Oxygen Requirement": "Facultative Anaerobe",
    "Growth Temperature": "35//37",
    "Catalase": "Negative",
    "Oxidase": "Positive",
    "Indole": "Positive",
    "Urease": "Negative",
    "Citrate": "Negative",
    "Methyl Red": "Negative",
    "VP": "Negative",
    "H2S": "Negative",
    "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": "Negative",
    "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"
  },

  "species_markers": [
    {
      "field": "Indole",
      "value": "Positive",
      "importance": "high",
      "notes": "Indole positivity is a key supportive trait for Cardiobacterium hominis within HACEK."
    },
    {
      "field": "Oxidase",
      "value": "Positive",
      "importance": "high",
      "notes": "Oxidase positivity supports Cardiobacterium over many oxidase-negative Gram-negative rods."
    },
    {
      "field": "Nitrate Reduction",
      "value": "Negative",
      "importance": "medium",
      "notes": "Helpful supporting feature when distinguishing from lookalike fastidious organisms with nitrate positivity."
    }
  ],

  "common_confusions": [
    {
      "species": "Cardiobacterium valvarum",
      "reason": "Closely related species; phenotypic differentiation may be limited without MALDI-TOF or molecular testing."
    },
    {
      "genus": "Aggregatibacter",
      "reason": "Shared HACEK grouping, slow growth, and similar clinical syndrome (endocarditis)."
    }
  ],

  "when_to_question_identification": [
    "Indole negative result (argues against classic C. hominis profile).",
    "Robust growth on routine media without enrichment or prolonged incubation.",
    "Oxidase negative isolate."
  ],

  "recommended_next_tests": [
    {
      "test": "Indole test",
      "reason": "Confirms indole positivity and supports Cardiobacterium hominis.",
      "api_kit": "API NH"
    },
    {
      "test": "Oxidase test",
      "reason": "Supports Cardiobacterium and narrows away from oxidase-negative Gram-negative rods.",
      "api_kit": "API NH"
    },
    {
      "test": "MALDI-TOF MS",
      "reason": "Best practical method for distinguishing Cardiobacterium species in routine labs."
    },
    {
      "test": "16S rRNA sequencing",
      "reason": "Recommended if MALDI-TOF is inconclusive or species-level certainty is required (e.g., endocarditis workup)."
    }
  ]
}