{ "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" } ] }