1357. Mycobacterium abscessus Native Tricuspid Valve Endocarditis. Is a 6-Week Course of Combination Antibiotic Therapy Enough?

BACKGROUND: Infective endocarditis of the native heart valves due to M. abscessus has been reported in individuals who inject drugs. Only one case thus far has been reported with survival beyond 4 months after completion of antibiotic therapy. 24-year-old Caucasian woman with a history of intravenous drug use presented with intermittent fevers for 3–4 months. She was having chills, night sweats, and productive cough. She acknowledged using intravenous cocaine and heroin every few days after being discharged from our hospital 6 months previously when she was treated for tricuspid valve endocarditis. Chest radiograph demonstrated right lower lobe airspace disease suggestive of pneumonia. Three days later her blood cultures grew acid-fast bacilli, later identified as M. abscessus. METHODS: She was empirically treated with azithromycin, amikacin, and imipenem. Transthoracic and transesophageal echocardiograms were suggestive of tricuspid valve endocarditis. CT angiogram of the chest showed filling defects within several large right lower lobe pulmonary arteries and dense right lower lobe consolidation with pleural effusion. The patient underwent bronchoscopy with bronchoalveolar lavage (BAL) and therapeutic thoracoscopy with drainage and thoracostomy tube placement. BAL cultures also grew AFB. Multiple sets of blood cultures drawn after commencement of antibiotic therapy during the hospital course were negative. Drug susceptibilities were available 3 weeks later. The isolate was susceptible to amikacin. Linezolid, imipenem, and cefoxitin exhibited intermediate activity, and TMP/SMX, ciprofloxacin, moxifloxacin, doxycycline, minocycline, and clarithromycin were reported resistant. Inducible erm gene was present. Azithromycin and linezolid were discontinued and tigecycline was added. RESULTS: Patient completed 6 weeks of antibiotics from the day of the first negative blood culture. Repeat TTE 1 month after completion of therapy revealed a decrease in tricuspid valve vegetation. Blood culture done 3 months later was sterile. AFB blood cultures done a year later did not report any growth. CONCLUSION: This case opens a debate, if in a selected group of patients, a short course of combination antibiotic therapy is enough to obtain cure. This will require further analysis. [Image: see text] [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.