Micro| Nocardia and Actinomyces (Branching Filamentous Species)

3.11 Nocardia and Actinomyces (Branching Filamentous Species) Microbiology review for the USMLE Step 1 exam Nocardia and Actinomyces are two gram positive bacteria that grow in filaments, resembling fungal hyphae. Both are associated with chronic pulmonary lesions, subcutaneous abscesses, and multiple draining sinuses. Both are capable of producing sulfur granules. Actinomyces is anaerobic and colonizes the mouth, GI, and urinary tracts. It can cause "lumpy jaw syndrome" and requires a long course of high dose penicillin. Nocardia is aerobic and stains weakly acid fast. It is found in the environment and typically causes cutaneous disease in immunocompetent individuals and pulmonary disease in immunocompromised individuals. Treatment for Nocardia typically involves a combination of antibiotics such as sulfonamides and trimethoprim-sulfamethoxazole. SNAP mnemonic: Sulfa for Nocardia; Actinomyces gets Penicillin.