mycobacterium abscessus subsp . abscessus ( mab ) lung disease is the most important cause of a non - tuberculous mycobacterium ( ntm ) infection , as it is considered a chronic infection that is incurable with current antibiotic therapy . moreover , the simultaneous detection of mycobacterium tuberculosis ( mtb ) and ntm in patients with presumptive pulmonary tuberculosis ( ptb ) at the time of diagnosis is not considered uncommon , although patients treated for ntm lung disease co - infected with mtb are very rare . herein , we describe a case of the successful treatment of a mixed lung infection with mab and mtb by pneumonectomy followed by inhaled amikacin therapy . in march 2011 , a 59-year - old woman was referred to busan paik hospital because of intermittent hemoptysis . she had no history of smoking or alcoholism , and no medical history other than that of ptb cured 27 years ago . on examination chest computed tomography ( ct ) revealed bronchiectasis and bronchiolitis mainly in the left upper lung ( lul ) and right upper lobe ( rul ) ( fig . ntm was isolated 3 times from consecutive sputum specimens , and identified as mab in all the isolates . she was diagnosed with mab lung disease on the basis of the appropriate diagnostic guidelines . she was followed up without antibiotic therapy because of her mild symptoms . during the 2 years after the diagnosis of mab lung disease , her cough gradually worsened , with an increase in the quality of purulent sputum and intermittent hemoptysis . moreover , the sputum smear status changed from negative to positive with radiological progression on chest ct ( fig . she received oral azithromycin along with an initial 4-week course of intravenous amikacin and cefoxitin . during the initial antibiotic treatment , her symptoms and ct lesions improved and the sputum smear changed to negative at weeks 3 and 4 of the treatment , although mab was consistently cultivated ( fig . 2 ) . antibiotic treatment via oral azithromycin was continued after 4 weeks of the combination therapy . follow - up sputum cultures remained persistently positive for mab , and the smear status of the sputum again changed to positive after 4 months . in november 2013 , 6 months after the initial combination therapy , she revisited our clinic because of fever and worsened sputum . she was diagnosed with pneumonia in the lul and treated with oral moxifloxacin , which led to some improvement in her condition ( fig . surprisingly , however , both mtb and mab were identified from 2 consecutive sputum samples . we treated her with isoniazid , rifampicin , ethambutol , and pyrazinamide , while assessing the possibility of a combined infection of mab and mtb in the repeated sputum and bronchial washing samples . these tests yielded the same result ; unfortunately , a drug sensitivity test could not be conducted because of the mixed colonies of mycobacteria . we decided to treat her with a 4-week course of intravenous amikacin and cefoxitin once more , along with oral azithromycin and anti - tuberculosis ( tb ) medication . despite the add - on therapy , her follow - up sputum smears remained consistently positive , and eventually , her entire left lung was destroyed and collapsed ( fig . 2 and fig . she underwent left pneumonectomy because of the persistent positive smear in the acid - fast bacilli stain and resistance to the antibiotic therapy . pathological examinations of the surgically resected specimen showed chronic granulomatous inflammation , and a mixed infection of mtb and mab was confirmed in a subsequent mycobacterial culture of the lung tissue . antibiotics targeting mab were continued for a week after surgery , followed by inhaled amikacin ( 500 mg / day ) along with oral azithromycin for 12 months , as she had another small lung lesion suggesting a mab infection in the rul . anti - tb therapy was maintained for a total of 6 months . a completely negative sputum smear and culture conversion of mtb and mab were achieved immediately after surgery and maintained until the completion of the antibiotic treatment ( fig . the patient remained well , without relapse of the mab lung disease , at a 1-year follow - up after the completion of therapy . a mixed infection involving ntm and mtb in the lung is a very rare clinical manifestation , although polyclonal and mixed infections of ntm and mtb have been reported . however , the simultaneous detection of ntm species in respiratory specimens with underlying ptb can occur , and such an infection is not considered a true concurrent infection because ntm is ubiquitous in the environment . thus , most studies have focused on distinguishing ntm lung disease from ptb at the time of the initial diagnosis , at the recurrence of ptb , and during follow - up examinations while treating ptb . moreover , there is only one previous report in the literature about a concurrent infection of ntm and mtb in an immune - compromised host , while none involving immune - competent hosts have been published . in our case , however , at 4 weeks after pneumonia , we noticed the concurrent mtb infection from the repeated results of the cultures conducted to assess mab lung disease , which was unexpected because of its rarity . previous studies dispute whether the use of fluoroquinolone in pneumonia contributes to delays in the diagnosis of ptb . the 2009 korean guideline for community - acquired pneumonia ( cap ) , not yet revised , recommended that the use of fluoroquinolone as the first - line therapy for cap be avoided in the setting of ptb , because south korea has an intermediate tb burden . our patient already had multiple bronchiectasis ; hence , we treated her with moxifloxacin , based on her structural lung disease . moreover , the management of her concurrent ntm and mtb infection was further complicated , as she already had a history of ptb and had been treated with several antibiotics for the mab lung disease . further , the possibility of drug - resistant ( dr ) mtb required investigation . however , we could not conduct a drug sensitivity test by either the phenotypic or the genotypic method , because the colonies of mtb were mixed with those of ntm . her left lung continued to deteriorate over time , despite anti - tb and anti - mab medication ; fortunately , her right lung was relatively conserved . many previous studies have reported that surgical resection has played an important role in the treatment of refractory ntm and dr - mtb infections of the lung . in our case , surgical resection was also an effective treatment of her concurrent mtb infection with a suspected dr pathogen and medically refractory mab lung disease with a unilateral destruction of the lung . it is recommended that mab lung disease be treated with oral macrolide therapy in combination with intravenous amikacin and cefoxitin for 2 to 4 months , according to the revised guidelines for ntm [ 1 ] ; however , the prolonged use of systemic amikacin is limited because of its adverse effects . a recent study showed an effective outcome of negative culture conversion in 62% of refractory ntm lung disease cases when inhaled amikacin therapy was added . moreover , a study evaluating the effectiveness of inhaled amikacin for mab lung disease is currently ongoing . we treated the patient in this study with oral azithromycin , along with inhaled amikacin , for 12 months after pneumonectomy , and she has remained culture - negative to date . in conclusion , we successfully treated a patient with combined mab lung disease and ptb by pneumonectomy followed by inhaled amikacin therapy . to the best of our knowledge , thus far , this is the first description of a mixed lung infection involving mab and mtb in an immune - competent individual .
a mixed infection of mycobacterium abscessus subsp . 
 abscessus ( mab ) and mycobacterium tuberculosis ( mtb ) in the lung is an unusual clinical manifestation and has not yet been reported . 
 a 61-year - old woman had been treated for mab lung disease and concomitant pneumonia , and was diagnosed with pulmonary tuberculosis ( ptb ) . despite both anti - ptb and anti - mab therapy , her entire left lung was destroyed and collapsed . 
 she underwent left pneumonectomy and received medical therapy . 
 we were able to successfully treat her mixed infection by pneumonectomy followed by inhaled amikacin therapy . 
 to the best of our knowledge , thus far , this is the first description of a mixed mab and mtb lung infection .