Pulmonary Mycobacterium celatum in an Immunocompetent Patient Successfully Treated With Antimicrobial Chemotherapy

Abstract

Mycobacteriumcelatumpulmonary infection is uncommon in immunocompetent patient. The first reports described M.cellatum in animals and immunocompromised patient. Now in literature there are some reports which presented M.celatum in immunocompetent patient. We report also a case of pulmonary infection in immunocompetent patient. Keywords: Nontuberculous mycobacteria, Mycobacterium celatum, Lung disease. Introduction: Mycobacterium celatum was first described in 1993 and since then, sporadic reports have been published on the isolation of this mycobacterium from immunocompromised patients. M. celatum is phenotypically similar to Mycobacterium avium and Mycobacterium xenopi. M. celatum is a recently described organism. Several reports exist in the literature establishing this organism as a convincing pathogen among Human Immunodeficiency Virus (HIV) seropositive patients. However, there is no evidence of its pathogenicity among individuals whose immune function is not profoundly impaired. Case report: A 66 year old female Caucasian patient. Her medical history was unremarkable and does not use any medicine. There was no history of latent TB in childhood. Chest xray showed nodular infiltration bilaterally. Referred to our hospital, the results of the clinical laboratory tests were unremarkable, apart from elevated Erythrocyte sedementaion rate ESR and C-reactive protein. Human Immunodeficiency Virus (HIV) antibody test was negative. Sputum culture and acid fast smear were tackled. Computed tomography showed nodular changes bilaterally with bronchiectasis. Bronchoscopy was done. AFB was negative in both sputum and BAL, sputum culture showed Mycobacterium cellatum. Started with Rifaputin and then changed to Rifampicin, Ethambutol and Azithromax. Patient improved with treatment after 12 months, there has been no recurrence of symptoms after treatment completion. Discussion: This report of a pulmonary infection with M. celatum indicates not only the known nontuberculous mycobacteria, Mycobacterium kansasii, M. avium and Mycobacterium scrofulaceum, can cause infection in immunocompetent human. The organism was generally found to be susceptible to clarithromycin, azithromycin and ethambutol. Previous case report in Italy for patient with pulmonary M.celatum, showed unsuccessful treatment with antimycobacterium therapy. One patient died 6 weeks after starting antimycobacterium therapy from complication that was apparently related to the M.celatum infection. Two cases reported in korea and Japan, showed successful treatment in using antimicobacterial chemotherapy and combined pulmonary resection. Our patient completely recovered with treatment, there was no recurrence of symptoms and follow-up sputum and blood cultures were performed between 2 and 9 months after initiation of therapy; cultures for four patients remained negative. Chest x-ray control showed a decreased nodular infilteration even when followup was done after treatment. Conclusions: In summary, M. celatum can cause pulmonary infection in populations other than immunocompromised HIV seropostive patient. Treatment with a three or four drug combination, including clarithromycin and ethabutol, should result in considerable reduction in the illness associated with the disease.