{ "schema_version": "1.0", "level": "species", "genus": "Cryptococcus", "species": "gattii", "overview": { "short": "Cryptococcus gattii is an encapsulated yeast capable of causing pulmonary and CNS disease, including in immunocompetent hosts.", "clinical_context": "Associated with pulmonary masses (cryptococcomas) and meningoencephalitis; classically linked to environmental exposure." }, "expected_fields": { "Gram Stain": "Variable", "Shape": "Yeast", "Motility": "Negative", "Capsule": "Positive", "Spore Formation": "Negative", "Haemolysis": "Negative", "Haemolysis Type": "None", "Media Grown On": [ "Sabouraud Dextrose Agar", "Blood Agar" ], "Colony Morphology": [ "Mucoid", "Cream", "Smooth" ], "Oxygen Requirement": "Aerobe", "Growth Temperature": "25//37", "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": "Positive", "Gas Production": "Negative", "TSI Pattern": "Unknown", "Colony Pattern": "Unknown", "Pigment": "None", "Motility Type": "None" }, "species_markers": [ { "field": "Capsule", "value": "Positive", "importance": "high", "notes": "Encapsulation is expected and clinically important." }, { "field": "Urease", "value": "Positive", "importance": "high", "notes": "Supports Cryptococcus identification." }, { "field": "Growth Temperature", "value": "25//37", "importance": "medium", "notes": "Growth at 37°C supports pathogenic Cryptococcus species." } ], "common_confusions": [ { "species": "Cryptococcus neoformans", "reason": "Very similar phenotype; routine biochemical fields often overlap." }, { "genus": "Rhodotorula", "reason": "Some species are urease-positive yeasts; pigmentation differences help but may be subtle." } ], "when_to_question_identification": [ "Capsule not demonstrated argues against Cryptococcus gattii.", "Urease negativity suggests a different yeast genus.", "A strong carbohydrate fermentation profile is inconsistent with Cryptococcus." ], "recommended_next_tests": [ { "test": "India ink preparation", "reason": "Demonstrates characteristic capsule.", "api_kit": "Not applicable" }, { "test": "MALDI-TOF MS", "reason": "Practical route to species-level ID vs C. neoformans complex.", "api_kit": "Not applicable" }, { "test": "Molecular identification", "reason": "Useful for complex-level discrimination where phenotype overlaps.", "api_kit": "Not applicable" } ] }