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

BACKGROUND: Tuberculosis is globally the most important cause of death from single pathogen. Rapid and accurate identification of mycobacteria is essential for the control of tuberculosis. We evaluated a fluorescence in situ hybridization (FISH) method using peptide nucleic acid (PNA) probes for the differentiation of Mycobacterium tuberculosis complex (MTB) and nontuberculous mycobacteria (NTM) in direct smears of sputum specimens. METHODS: The cross-reactivity of MTB- and NTM-specific PNA probes was examined with reference strains of M. tuberculosis ATCC 13950, Mycobacterium kansasii ATCC 12479, Mycobacterium fortuitum ATCC 6841, several clinical isolates of mycobacteria (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium gordonae and Mycobacterium chelonae), and 11 frequently isolated respiratory bacterial species other than mycobacteria. A series of 128 sputa (89 MTB culture positive, 29 NTM culture positive, and 10 under treatment culture negative) with grades of trace to 4+ were used to evaluate the performance of the method. RESULTS: The MTB- and NTM-specific PNA probes showed specific reactions with the reference strains of MTB and M. kansasii and clinical isolates of mycobacteria except M. fortuitum ATCC 6841, and no cross-reactivity with other tested bacteria. The PNA probe-based FISH assay for detection of MTB had a sensitivity and specificity of 100%, respectively. The sensitivity and specificity of the NTM-specific PNA probe was 100%. The smear grades of the PNA FISH test were same as with those of the fluorescence AFB stain in 2+ or higher grade. CONCLUSION: Detection and differentiation based on PNA FISH is sensitive and accurate for detecting mycobacteria and for differentiating MTB from NTM in clinical sputum smears.
Bacteria ; Cause of Death ; Fluorescence* ; In Situ Hybridization* ; Mycobacterium ; Mycobacterium avium ; Mycobacterium avium Complex ; Mycobacterium fortuitum ; Mycobacterium kansasii ; Mycobacterium tuberculosis* ; Nontuberculous Mycobacteria* ; Peptide Nucleic Acids ; Sputum ; Tuberculosis

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

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

Paratuberculosis caused by Mycobacterium avium subsp. paratuberculosis (MAP) has extended latent periods of infection. Due to this property, difficulties in the detection of fecal shedder have been raised. A newly designed method for DNA extraction from fecal specimens, mGITC/SC was evaluated in terms of diagnostic efficiency. The detection limit of IS900 real-time PCR was about 50 MAP (1.5 cfu) in 250 mg of feces (6 cfu per g). Also, this DNA extraction method was faster and cheaper than that using commercial kit or other methods. Consequently, the mGITC/SC is an economical DNA extraction method that could be a useful tool for detecting MAP from fecal specimens.
Animals ; DNA* ; Feces* ; Limit of Detection ; Mycobacterium avium subsp. paratuberculosis* ; Mycobacterium avium* ; Mycobacterium* ; Paratuberculosis ; Real-Time Polymerase Chain Reaction

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

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