{ "schema_version": "1.0", "level": "species", "genus": "Cedecea", "species": "davisae", "overview": { "short": "Cedecea davisae is a rare, Gram-negative, facultatively anaerobic rod within the Enterobacterales.", "clinical_context": "Occasionally isolated from opportunistic infections including bacteremia and respiratory infections, primarily in immunocompromised patients." }, "expected_fields": { "Gram Stain": "Negative", "Shape": "Rods", "Motility": "Positive", "Capsule": "Variable", "Spore Formation": "Negative", "Haemolysis": "Negative", "Haemolysis Type": "None", "Media Grown On": [ "MacConkey Agar", "Blood Agar" ], "Colony Morphology": [ "Smooth", "Grey", "Moist" ], "Oxygen Requirement": "Facultative Anaerobe", "Growth Temperature": "30//37", "Catalase": "Positive", "Oxidase": "Negative", "Indole": "Negative", "Urease": "Negative", "Citrate": "Positive", "Methyl Red": "Negative", "VP": "Positive", "H2S": "Negative", "DNase": "Negative", "ONPG": "Positive", "Coagulase": "Negative", "Gelatin Hydrolysis": "Variable", "Esculin Hydrolysis": "Negative", "Nitrate Reduction": "Positive", "NaCl Tolerant (>=6%)": "Negative", "Lipase Test": "Negative", "Lysine Decarboxylase": "Negative", "Ornithine Decarboxylase": "Positive", "Ornitihine Decarboxylase": "Positive", "Arginine dihydrolase": "Negative", "Glucose Fermentation": "Positive", "Lactose Fermentation": "Negative", "Sucrose Fermentation": "Variable", "Maltose Fermentation": "Positive", "Mannitol Fermentation": "Positive", "Sorbitol Fermentation": "Variable", "Xylose Fermentation": "Positive", "Rhamnose Fermentation": "Negative", "Arabinose Fermentation": "Positive", "Raffinose Fermentation": "Negative", "Trehalose Fermentation": "Positive", "Inositol Fermentation": "Negative", "Gas Production": "Variable", "TSI Pattern": "A/A", "Colony Pattern": "Unknown", "Pigment": "None", "Motility Type": "Peritrichous" }, "species_markers": [ { "field": "Ornithine Decarboxylase", "value": "Positive", "importance": "high", "notes": "Key discriminator separating C. davisae from C. lapagei." }, { "field": "Lysine Decarboxylase", "value": "Negative", "importance": "medium", "notes": "Supports differentiation from some Enterobacter species." } ], "common_confusions": [ { "species": "Cedecea lapagei", "reason": "Closely related species with overlapping biochemical reactions." }, { "genus": "Enterobacter", "reason": "Shared citrate and VP positivity may cause misidentification." } ], "when_to_question_identification": [ "Ornithine decarboxylase is negative.", "Lactose fermentation is present.", "Indole is positive." ], "recommended_next_tests": [ { "test": "Ornithine decarboxylase", "reason": "Primary discriminator between Cedecea species.", "api_kit": "API 20E" }, { "test": "MALDI-TOF MS", "reason": "Reliable confirmation for rare Enterobacterales species." } ] }