A Leuconostoc Lung Abscess With Empyema in an Immunocompetent Host

Abstract

SESSION TITLE: Student/Resident Case Report Poster - Chest Infections II SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Leuconostocs are gram positive, catalase negative bacteria comprising of L mesenteroides, citreum, lactis and others. Infections due to Leuconostocs in immunocompetent individuals without risk factors are rare. We present this case of a Leuconostoc lung empyema in a healthy immunocompetent individual. CASE PRESENTATION: A 63 year old male with a history of COPD and thoracic aortic aneurysm was transferred to our hospital because of findings of right middle lobe abscess and empyema. He initially presented with complaints of 6 weeks cough with brownish sputum, and right-sided pleuritic chest pain. Initial labs had revealed a WBC of 22,000 while CXR showed right middle lobe consolidation. He had been treated with clindamycin and meropenem because he had failed outpatient levofloxacin. When he failed to improve, a chest CT revealed a right middle lobe abscess with possible empyema. Subsequently, patient was transferred to our facility where he underwent thoracotomy with decortication. Intraoperatively, consolidation of the right middle lobe with purulent oozing was noted and right middle lobectomy was done. He was started on vancomycin and meropenem, which were discontinued when pleural fluid cultures revealed Leuconostoc. The patient was treated with 14 days of clindamycin. DISCUSSION: Leuconostocs are lactobacilli which were previously classified under the Streptococcacae family. They are resistant to vancomycin due to alterations in the cell wall binding site. They are commonly found in pickles, legumes, dairy products and fermentation industries including wine and sugar industries. Predisposing factors include prior vancomycin treatment, immunocompromise, ESRD with hemodialysis, central venous catheterization and severe burns. Leuconostocs are known to cause a wide range of infections including meningitis, line-associated infection, pneumonia, osteomyelitis, subacute bacterial endocarditis and intra-abdominal infections. Very few cases have been reported in immunocompetent individuals with no risk factors. Treatment is recommended with ampicillin, clindamycin, aminoglycosides, cephalosporins or imipenem. CONCLUSIONS: Leuconostocs are morphologically similar to streptococcus but is differentiated by being the only catalase-negative cocci that are also leucin aminopeptidase and pyrrolidonylarylamidase negative. Our patient was unique in his presentation with Leuconostoc lung abscess and empyema in the absence of risk factors. Reference #1: Facklam R, Elliott JA. Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci. Clin Microbiol Rev. 1995;8(4):479-495. Reference #2: Yang C, Wang D, Zhou Q, Xu J. Bacteremia due to vancomycin-resistant leuconostoc lactis in a patient with pneumonia and abdominal infection. Am J Med Sci. 2015;349(3):282-283. Reference #3: Golan Y, Poutsiaka DD, Tozzi S, Hadley S, Snydman DR. Daptomycin for line-related leuconostoc bacteraemia. J Antimicrob Chemother. 2001;47(3):364-365. DISCLOSURE: The following authors have nothing to disclose: Siddique Chaudhary, Wajdi Al Shweiat, Ahmed Hamdi, John Youssef, Susan Smith No Product/Research Disclosure Information