data/rag/knowledge_base/Cryptococcus/laurentii.json

{
  "schema_version": "1.0",
  "level": "species",
  "genus": "Cryptococcus",
  "species": "laurentii",

  "overview": {
    "short": "Cryptococcus laurentii is an environmental yeast occasionally implicated in opportunistic infection, typically less virulent than C. neoformans/gattii.",
    "clinical_context": "Rarely isolated from clinical specimens; when involved, often in immunocompromised hosts or device-associated settings."
  },

  "expected_fields": {
    "Gram Stain": "Variable",
    "Shape": "Yeast",
    "Motility": "Negative",
    "Capsule": "Variable",
    "Spore Formation": "Negative",
    "Haemolysis": "Negative",
    "Haemolysis Type": "None",
    "Media Grown On": [
      "Sabouraud Dextrose Agar",
      "Blood Agar"
    ],
    "Colony Morphology": [
      "Smooth",
      "Cream",
      "Moist"
    ],
    "Oxygen Requirement": "Aerobe",
    "Growth Temperature": "20//35",
    "Catalase": "Positive",
    "Oxidase": "Negative",
    "Indole": "Negative",
    "Urease": "Positive",
    "Citrate": "Negative",
    "Methyl Red": "Unknown",
    "VP": "Unknown",
    "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": "Negative",
    "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": "Variable",
    "Gas Production": "Negative",
    "TSI Pattern": "Unknown",
    "Colony Pattern": "Unknown",
    "Pigment": "None",
    "Motility Type": "None"
  },

  "species_markers": [
    {
      "field": "Capsule",
      "value": "Variable",
      "importance": "medium",
      "notes": "Encapsulation may be weak/variable compared with C. neoformans/gattii."
    },
    {
      "field": "Growth Temperature",
      "value": "20//35",
      "importance": "high",
      "notes": "Weaker growth at 37°C vs pathogenic complexes can support non-neoformans species."
    },
    {
      "field": "Inositol Fermentation",
      "value": "Variable",
      "importance": "medium",
      "notes": "Inositol utilization may be less consistent than in neoformans/gattii."
    }
  ],

  "common_confusions": [
    {
      "species": "Cryptococcus neoformans",
      "reason": "Both can be urease-positive yeasts; capsule and growth at 37°C are often more robust in C. neoformans."
    },
    {
      "genus": "Rhodotorula",
      "reason": "Environmental yeasts can overlap; pigmentation differences may help but are not always reported."
    }
  ],

  "when_to_question_identification": [
    "Strong capsule plus consistent 37°C growth may indicate C. neoformans/gattii instead.",
    "Urease negativity suggests other yeast genera.",
    "A strong sugar fermentation profile is inconsistent with Cryptococcus."
  ],

  "recommended_next_tests": [
    {
      "test": "MALDI-TOF MS",
      "reason": "Best practical discriminator for non-neoformans Cryptococcus species.",
      "api_kit": "Not applicable"
    },
    {
      "test": "Growth at 37°C",
      "reason": "Helps separate pathogenic complexes from more environmental species.",
      "api_kit": "Not applicable"
    },
    {
      "test": "Molecular identification",
      "reason": "Useful if MALDI is inconclusive or to confirm unusual isolates.",
      "api_kit": "Not applicable"
    }
  ]
}