Micro| Bartonella Henselae

3.18 Bartonella Henselae Microbiology review for the USMLE Step 1 exam Bartonella henselae is an intracellular gram negative rod that causes several different diseases Bartonella targets and lives inside specialized immune cells called CD34+ cells Bartonella creates a protective vacuole that protects it and helps it evade immune detection Bartonella henselae is a facultative intracellular bacteria Three different clinical syndromes associated with bartonella henselae: cat scratch disease, bacillary angiomatosis in immunocompromised patients, and bacterial endocarditis Cat scratch disease presents with cutaneous manifestations at the site of inoculation (warm, red, swollen, with a vesicle) and swollen lymph nodes near the site Bacillary angiomatosis symptoms include fever, multiple clustered red or violaceous papules or nodules on the skin and mucosa, and bone pain Bacterial endocarditis: Bartonella makes its way into the bloodstream and infects the inner surface of the heart Bartonella henselae is hard to culture from blood, usually diagnosed via serology Treatment depends on the clinical syndrome presented, cat scratch disease is usually self-limited and doesn’t necessarily require antibiotics, bacillary angiomatosis treated with a long 4-month course of either erythromycin or doxycycline.