| { |
| "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" |
| ] |
| } |
