No abstract available.
Mycobacterium avium Complex* ; Mycobacterium avium* ; Mycobacterium*

Recently, selective PCR method using DT1 and DT6 sequences was introduced to identify and differentiate the Mycobacterium avium complex (MAC) into M. intracellulare and M. avium. We applied this method to 49 MAC clinical isolates identified by biochemical tests. They were differentiated into 39 strains of M. intracelluare and 10 strains of M. avium. Compared to those results obtained by 16S rDNA sequencing, DT1-DT6 PCR method showed 100% specificity. While the sensitivity of DT6 PCR for M. avium was 100%, that of DT1 PCR for M. intracellulare was 84.6%. These results show heterogeneity of M intracellulare Korea clinical isolates from Korea. In conclusion, although the in-house DTl-DT6 PCR is an easy and convenient method in differentiating MAC members, other methods such as 16S rDNA sequencing analysis should be performed for the correct identification, especially of M intracellulare.
DNA, Ribosomal ; Korea* ; Mycobacterium avium Complex* ; Mycobacterium avium* ; Mycobacterium* ; Polymerase Chain Reaction* ; Population Characteristics ; Sensitivity and Specificity

The global number of Mycobacterium avium complex (MAC) pulmonary infection is increasing. Patients with preexisting lung disease or who are immunodeficient are at the greatest risk for developing MAC infection. Endobronchial lesions with MAC infection are rare in the immunocompetent host. However, there have been an increasing number of reports of an immunocompetent host being afflicted with various manifestations of MAC infection. We report a case of pulmonary and endobronchial MAC infection presenting as an acute pneumonia in a 59-year-old female without preexisting lung disease or immunodeficiency.
Female ; Humans ; Lung Diseases ; Middle Aged ; Mycobacterium ; Mycobacterium avium ; Mycobacterium avium Complex ; Pneumonia

Non-tuberculous mycobacteria (NTM) are being recognized increasingly as the causative agents of opportunistic infections in humans. This study investigated the epidemiologic trends of NTM recovery from various clinical specimens in 2 Korean tertiary-care hospitals. We reviewed the laboratory records of patient samples cultured for mycobacteria between 2009 and 2015 at 2 tertiary-care hospitals in Korea. The medical records for patients with positive NTM samples were also reviewed. During the study period, 144,540 specimens were cultured for mycobacteria. The proportion of NTM-positive samples increased from 23.3% in 2009 to 48.2% in 2015. The 2 most frequently isolated NTM were Mycobacterium intracellulare (38.3%) and M. avium (23.1%). The number of clinically significant diseases caused by NTM in inpatients and outpatients increased from 6.8 to 12.9 per 100,000 patients over the same period. The rates of recovery of NTM from clinical specimens and the number of patients with NTM infections increased significantly (P < 0.001, testing for trend) between 2009 and 2015.
Humans ; Inpatients ; Korea ; Medical Records ; Mycobacterium avium ; Mycobacterium avium Complex ; Mycobacterium tuberculosis ; Opportunistic Infections ; Outpatients

Nontuberculous mycobacterial infection is rarely accompanied by pleural involvement. We report a very rare case of Mycobacterium intracellulare pulmonary disease accompanied with pleural effusion. A 76-year-old man was admitted to our hospital because of dyspnea. A chest radiograph and CT showed bilateral bronchiectasis and bronchopneumonia accompanied with right pleural effusion. The fluid was lymphocyte-dominant exudative effusion, and microbiological examinations of the effusion, including staining and culturing, proved negative. However, one month after admission, subsequent cultures of bronchial washing fluid revealed the presence of M. intracellulare. The patient's effusion was gradually resolved with antibiotic treatment, including clarithromycin.
Aged ; Bronchiectasis ; Bronchopneumonia ; Dyspnea ; Humans ; Lung Diseases ; Mycobacterium ; Mycobacterium avium Complex ; Mycobacterium avium-intracellulare Infection ; Pleural Effusion ; Thorax

The Mycobacterium avium complex (MAC) is the most common pathogen causing nontuberculous mycobacterial pulmonary disease. Despite the introduction of newer, more effective agents for the treatment of MAC, such as clarithromycin, the response to drug therapy in MAC pulmonary disease remains poor, and often frustrating. When MAC pulmonary disease has not been successfully eradicated using drug treatment alone, surgical management is still recognized to play a significant role. A case of MAC pulmonary disease, in a patient whose MAC disease was successfully treated by pulmonary resection, following the failure of drug therapy containing clarithromycin, is reported. To our knowledge, this is the first case report in Korea that the patient underwent a pulmonary resection for the treatment of MAC pulmonary disease.
Clarithromycin ; Drug Therapy* ; Humans ; Korea ; Lung Diseases* ; Mycobacterium avium Complex ; Mycobacterium avium* ; Mycobacterium* ; Nontuberculous Mycobacteria ; Thoracic Surgery

Mycobacterium avium complex (MAC) comprises M. intracellulare and M. avium. MAC usually causes pulmonary diseases in individuals with intact immunity, disseminated disease in patients with acquired immunodeficiency syndrome, and cervical lymphadenitis. It can also cause cutaneous disease, but musculoskeletal infection is rare. Herein, we present a case of vertebral osteomyelitis due to M. intracellulare in an elderly immunocompetent patient who underwent vertebroplasty. The patient was successfully treated with antimycobacterial drugs without surgical intervention. MAC should be considered as a causative pathogen of vertebral osteomyelitis when the patient has a history of vertebroplasty.
Acquired Immunodeficiency Syndrome ; Aged* ; Humans ; Lung Diseases ; Lymphadenitis ; Mycobacterium avium Complex* ; Mycobacterium avium-intracellulare Infection ; Mycobacterium* ; Nontuberculous Mycobacteria ; Osteomyelitis* ; Vertebroplasty*

A recent study showed that comparative sequence analysis of rpoB DNAs could reveal natural relationships in genus Mycobacterium [J Clin Microbiol. 37 (6). 1999]. rpoB DNAs showed interspecies variation and intraspecies conservation, Based on these data, we developed polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) protocols which enable species differentiation in genus Mycabacterium. When this assay was applied to 24 clinical isolates identified as M. avium complex (MAC) by biochemical test, these were successfully differentiated into M. avium and M. intracellulare. These results were concordant with those obtained by 16s rDNA analysis. It is the first report that PCR-SSCP analysis of rpoB DNA could be used for species differentiation of MAC strains.
DNA* ; DNA, Ribosomal ; Mycobacterium avium Complex* ; Mycobacterium avium* ; Mycobacterium* ; Polymerase Chain Reaction* ; Polymorphism, Single-Stranded Conformational* ; Sequence Analysis

Nontuberculous mycobacteria (NTM) have been increasingly recognized as an important cause of chronic pulmonary infections. The Mycobacterium avium complex (MAC), which is composed of two species, Mycobacterium avium and Mycobacterium intracelluare, is the most commonly encountered pathogen associated with NTM lung disease. MAC pulmonary infection typically presents in a fibrocavitary form or a nodular bronchiectatic form. However, there have been atypical presentations of MAC pulmonary infections, including solitary pulmonary nodules (SPN). There have been several previous reports of SPN due to MAC infection in the United States, Japan, and Korea. In 2009, Sekine and colleagues reported a case of MAC pulmonary infection presenting with multiple nodules. To date, however, there have been no cases of NTM lung infection with multiple cavitary pulmonary nodules, and neither a fibrotic change nor nodular bronchiectasis. The present case showed a multiple cavitating nodular lung infection due to MAC, which is very rare and different from the typical presentation of MAC pulmonary infections. We also showed that percutaneous transthoracic needle aspiration can be a useful diagnostic tool to evaluate a case of multiple cavitary nodules.
Bronchiectasis ; Japan ; Korea ; Lung ; Lung Diseases ; Mycobacterium avium ; Mycobacterium avium Complex* ; Mycobacterium* ; Needles ; Nontuberculous Mycobacteria ; Solitary Pulmonary Nodule ; United States

The Mycobacterium avium-intracellulare complex (MAC) is the most common pathogen in pulmonary disease caused by a nontuberculous mycobacteria. Patients with MAC pulmonary disease tend to be older, are more likely to have underlying lung disease than tuberculosis patients. The insidious nature of MAC pulmonary disease has been emphasized in many reports because symptoms may be present for months or years before a diagnosis can be made. Most patients experience chronic coughing, which is usually productive of purulent sputum. A MAC pulmonary infection is rarely accompanied by acute respiratory symptoms and lobar pneumonic consolidation on chest radiography. We report a very rare case of M. intracellulare pulmonary disease presenting as acute pneumonia.
Cough ; Diagnosis ; Humans ; Lung Diseases ; Mycobacterium avium Complex* ; Mycobacterium avium-intracellulare Infection ; Mycobacterium* ; Nontuberculous Mycobacteria ; Pneumonia* ; Radiography ; Sputum ; Thorax ; Tuberculosis