data/rag/knowledge_base/Abiotrophia/genus.json

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

  "overview": {
    "short": "Abiotrophia species are fastidious Gram-positive cocci, historically classified as nutritionally variant streptococci, requiring enriched media or growth factors for optimal growth.",
    "clinical_context": "Primarily associated with infective endocarditis and other invasive infections, particularly in blood culture isolates."
  },

  "expected_fields": {
    "Gram Stain": "Positive",
    "Shape": "Cocci",
    "Motility": "Negative",
    "Capsule": "Unknown",
    "Spore Formation": "Negative",
    "Haemolysis": "Variable",
    "Haemolysis Type": "Variable",
    "Media Grown On": [
      "Blood Agar",
      "Chocolate Agar"
    ],
    "Colony Morphology": [
      "Small",
      "Grey",
      "Translucent"
    ],
    "Oxygen Requirement": "Facultative Anaerobe",
    "Growth Temperature": "35//37",
    "Catalase": "Negative",
    "Oxidase": "Negative",
    "Indole": "Negative",
    "Urease": "Negative",
    "Citrate": "Negative",
    "Methyl Red": "Unknown",
    "VP": "Unknown",
    "H2S": "Negative",
    "DNase": "Negative",
    "ONPG": "Unknown",
    "Coagulase": "Negative",
    "Gelatin Hydrolysis": "Negative",
    "Esculin Hydrolysis": "Negative",
    "Nitrate Reduction": "Negative",
    "NaCl Tolerant (>=6%)": "Negative",
    "Lipase Test": "Negative",
    "Lysine Decarboxylase": "Unknown",
    "Ornithine Decarboxylase": "Unknown",
    "Ornitihine Decarboxylase": "Unknown",
    "Arginine dihydrolase": "Negative",
    "Glucose Fermentation": "Positive",
    "Lactose Fermentation": "Negative",
    "Sucrose Fermentation": "Variable",
    "Maltose Fermentation": "Variable",
    "Mannitol Fermentation": "Negative",
    "Sorbitol Fermentation": "Negative",
    "Xylose Fermentation": "Negative",
    "Rhamnose Fermentation": "Negative",
    "Arabinose Fermentation": "Negative",
    "Raffinose Fermentation": "Negative",
    "Trehalose Fermentation": "Variable",
    "Inositol Fermentation": "Negative",
    "Gas Production": "Negative",
    "TSI Pattern": "Unknown",
    "Colony Pattern": "Unknown",
    "Pigment": "None",
    "Motility Type": "None"
  },

  "field_notes": {
    "Media Grown On": "Growth is often poor on standard Blood Agar unless pyridoxal or satellite growth around helper organisms is present.",
    "Haemolysis": "Haemolytic reactions are inconsistent and not reliable for identification.",
    "ONPG": "Typically not reported due to fastidious growth requirements."
  },

  "key_differentiators": [
    {
      "field": "Catalase",
      "expected": "Negative",
      "distinguishes_from": ["Staphylococcus"],
      "notes": "Catalase negativity separates Abiotrophia from staphylococci."
    },
    {
      "field": "Media Grown On",
      "expected": "Fastidious growth",
      "distinguishes_from": ["Streptococcus", "Enterococcus"],
      "notes": "Requirement for enriched media or growth factors distinguishes Abiotrophia from most streptococci."
    },
    {
      "field": "NaCl Tolerant (>=6%)",
      "expected": "Negative",
      "distinguishes_from": ["Enterococcus"],
      "notes": "Lack of salt tolerance helps separate from enterococci."
    }
  ],

  "common_confusions": [
    {
      "genus": "Streptococcus",
      "reason": "Similar Gram-positive cocci morphology and catalase-negative profile."
    },
    {
      "genus": "Granulicatella",
      "reason": "Closely related nutritionally variant streptococci with overlapping phenotypes."
    }
  ],

  "when_to_question_identification": [
    "Failure to grow on routine media without supplementation.",
    "Blood culture isolate with streptococcus-like morphology but inconsistent biochemical results.",
    "Endocarditis isolate that does not fully match Streptococcus profiles."
  ],

  "recommended_next_tests": [
    {
      "test": "Pyridoxal supplementation or satellite test",
      "reason": "Confirms nutritionally variant growth requirements."
    },
    {
      "test": "MALDI-TOF MS",
      "reason": "Preferred for reliable genus and species-level identification."
    },
    {
      "test": "16S rRNA sequencing",
      "reason": "Recommended when phenotypic identification is inconclusive."
    }
  ],

  "supported_species": [
    "defectiva"
  ]
}