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

BACKGROUND: Pulmonary infection with nontuberculous mycobacteria (NTM) is increasing in South Korea. Since treatment strategy differs by NTM species, accurate identification is necessary. In this study, using Mycobacterium pulmonary isolates recently recovered from a general hospital in Seoul, the prevalence of NTM isolates was investigated. METHODS: A total of 483 Mycobacterium pulmonary strains isolated between May and November 2018 from an 814-bed general hospital in South Korea were analyzed. Bacterial species were identified based on nucleotide sequences of the 16S–23S rDNA internal transcribed spacer and the rpoB gene. RESULTS: From a total of 1,209 pulmonary specimens from patients suspected to be infected with mycobacteria, 324 deduplicate strains were isolated, comprising 90 Mycobacterium tuberculosis and 229 NTM strains. Among the NTM isolates, 61.5% (n=144) were Mycobacterium avium complex (MAC), including 92 M. avium and 52 Mycobacterium intracellulare, while 8.1% (n=19) represented Mycobacterium abscessus, including 10 M. abscessus subsp. abscessus and 9 M. abscessus subsp. massiliense. In addition, 12 (5.1%) Mycobacterium lentiflavum, 12 (5.1%) Mycobacterium gordonae, 6 (2.6%) Mycobacterium kansasii, and 5 (2.1%) Mycobacterium fortuitum were identified. In addition, Mycobacterium mucogenicum (n=2), Mycobacterium septicum (n=1), Mycobacterium colombiens (n=1), Mycobacterium asiaticum (n=1), and Mycobacterium celatum (n=1) were identified. CONCLUSION: Among the recently recovered Mycobacterium pulmonary strains, more than half were identified as NTM, and MAC was the most prevalent NTM, followed by M. abcessuss.
Base Sequence ; DNA, Ribosomal ; Hospitals, General ; Humans ; Korea ; Mycobacterium ; Mycobacterium avium Complex ; Mycobacterium fortuitum ; Mycobacterium kansasii ; Mycobacterium tuberculosis ; Nontuberculous Mycobacteria ; Prevalence ; Seoul ; Tertiary Care Centers ; Tertiary Healthcare

As the prevalence of tuberculosis declines, the proportion of mycobacterial lung disease due to nontuberculous mycobacteria (NTM) is increasing worldwide. In Korea, Mycobacterium avium-intracellulare complex and Mycobacterium abscessus account for most of the pathogens encountered, whilst Mycobacterium kansasii is a relatively uncommon cause of NTM lung diseases. When NTM lung disease occurs, it is likely to present in one of two forms: apical fibrocavitary disease often affecting older male smokers with previous tuberculosis or chronic obstructive pulmonary disease; nodular bronchiectasis classically occurring in middle-aged or older woman who never smoked and present with cough. Because its clinical features are frequently indistinguishable from those of pulmonary tuberculosis and NTMs are ubiquitous in the environment, the isolation and identification of causative organisms are mandatory for diagnosis, and some specific diagnostic criteria have been proposed. Treatment of disease depends on the infecting species, extent and form of disease, and overall condition of the patient, but decisions concerning the institution of treatment are never easy. Treatment requires the use of multiple drugs for 18 to 24 months. Thus, treatment is expensive, often has significant side effects, and is frequently not curative. Surgery for localized disease may be useful for those species expected to be refractory to medical therapy. Observation without treatment may be appropriate for some patients with slowly progressive disease that is expected to be particularly difficult to treat.
Bronchiectasis ; Cough ; Female ; Humans ; Korea ; Lung ; Lung Diseases ; Male ; Mycobacterium ; Mycobacterium avium Complex ; Mycobacterium avium-intracellulare Infection ; Mycobacterium kansasii ; Nontuberculous Mycobacteria ; Prevalence ; Smoke ; Tuberculosis ; Tuberculosis, Pulmonary

BACKGROUNDAn increasing incidence of disease caused by nontuberculous mycobacteria (NTM) is being reported. The purpose of this study was to determine the isolation rates of NTM from various clinical specimens, and their antimicrobial susceptibility patterns, over a 4-year period in Shanghai.

METHODSAll NTM isolated between 2005 and 2008 at Shanghai Pulmonary Hospital, a key laboratory of mycobacteria tuberculosis in Shanghai, China, were identified with conventional biochemical tests and 16S rRNA gene sequencing. Antimicrobial susceptibility for all NTM was determined using the BACTEC MGIT 960 system.

RESULTSA total of 21,221 specimens were cultured, of which 4868 (22.94%) grew acid fast bacilli (AFB), and 248 (5.09%) of the AFB were NTM. The prevalence rate of NTM was determined as 4.26%, 4.70%, 4.96% and 6.38% among mycobacteria culture positive samples in years 2005, 2006, 2007 and 2008 respectively. These data indicated that the prevalence rate has continuously increased. Sixteen different species of NTM were identified, the most commonly encountered NTM in Shanghai were M. chelonae (26.7%), followed by M. fortuitum (15.4%), M. kansasii (14.2%), M. avium-intracellulare complex (13.1%) and M. terrae (6.9%). The rare species identified were M. marinum, M. gastri, M. triviale, M. ulcerans, M. smegmatis, M. phlci, M. gordonae, M. szulgai, M. simiae, M. scrofulaceum and M. xenopi. The five most commonly identified NTM species showed high drug resistance to general anti-tuberculosis drugs, particularly, M. chelonae and M. fortuitum appear to be multi-drug resistance.

CONCLUSIONSThe prevalence of NTM in Shanghai showed a tendency to increase over the course of the study. The five most commonly isolated NTM species showed high drug resistance to first line anti-tuberculosis drugs.

Antitubercular Agents ; pharmacology ; China ; epidemiology ; Drug Resistance, Bacterial ; Mycobacterium ; drug effects ; physiology ; Mycobacterium Infections ; epidemiology ; microbiology ; Mycobacterium chelonae ; drug effects ; physiology ; Mycobacterium fortuitum ; drug effects ; physiology ; Mycobacterium kansasii ; drug effects ; physiology ; Mycobacterium marinum ; drug effects ; physiology ; Mycobacterium xenopi ; drug effects ; physiology ; Nontuberculous Mycobacteria ; drug effects ; physiology ; Prevalence

Atypical mycobacteria, widely distributed in nature, are opportunistic infection strain, rare pathogen in immunocompetent patients. Recently, the increase of invasive cosmetic treatment and surgery has increased the infection of atypical mycobacteria. We report a case of cutaneous infection by Mycobacterium fortuitum and Mycobacterium intracellulare that occurred after a fat graft. A 62-year-old female patient presented painful, erythematous nodules and purulent discharge on her face after a fat graft. A skin biopsy and culture were performed. Polymerase chain reaction-hybridization to identify mycobacterium other than tuberculosis revealed M. fortuitum and M. intracellulare. The patient was treated with clarithromycin, rifampicin, and ethambutol for 1 month after excision and drainage of pus, after which the skin lesions improved. In cases of refractory cutaneous infection after an invasive cosmetic procedure, atypical mycobacterial infection should be suspected.
Biopsy ; Clarithromycin ; Coinfection* ; Drainage ; Ethambutol ; Female ; Humans ; Middle Aged ; Mycobacterium avium Complex* ; Mycobacterium fortuitum* ; Mycobacterium* ; Nontuberculous Mycobacteria ; Opportunistic Infections ; Rifampin ; Skin ; Suppuration ; Transplants* ; Tuberculosis

The differential diagnosis of atypical mycobacteriosis caused by atypical mycobacteria (with the exception of Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium leprae) which are widly distributed in soil and water, from pulmonary tuberculosis is possible only when atypical mycobacteria are isolated and identified. In this investigation, attempts were made to isolate atypical mycobacteria from persons registered as tuberculosis patients in the Anyang Health Center in Anyang City, Kyungki province, Korea. Biological and biochemical tests were performed for the atypical mycobacteria isolated from these patients, also retrospective analysis of clinical and X-ray findings of the patients with bacteriologically confirmed atypical mycobacteriosis were done. The results can be summarized as follows; 1. 103 strains of mycobacteria were isolated among 334 sputum samples from patients. 2. Among the isolated mycobacteria, 10 strains (9.7%) were found to be an atypical mycobacteria and 93 strains (90.3%) were tubercle bacilli of human type. 3. On the basis of Runyon's grouping of atypical mycobacteria, there were 3 strains (30.0%) of scotochromogen and nonphotochromogen respectively, 4 strains (40.0%) of rapid grower, and no photochromogen. 4. By biochemical tests, 3 strains of scotochromogen were identified as Mycobacterium scroful-aceum (2 strains) and Mycobacterium szulgai (1 strain) 3 strains of nonphotochromogen were Mycobacterium avium-complex (2 strains) and Mycobacterium terriae (1 strain), and 4 strains of rapid grower were Mycobacterium fortuitum (3 strains) and Mycobacterium chelonae. 5. In drug sensitivity tests, all 10 strains isolated atypical mycobacteria showed resistance to various concentration of INH and SM and low concentration (10 mcg, 40 mcg and 50 mcg) of EB, TH, and CS, and were sensitive to only high concentration (20 mcg and 100 mcg) of EB, TH, CS, and RFP. 6. In analysis of clinical findings by the patients with bacteriologically confirmed atypical mycobacteriosis, it was found that clinical symptoms of these patients appeared not to be mild than those of patients with pulmonary tuberculosis. The patients with atypical mycobacteriosis had been treated for pulmonary tuberculosis for a long time and they showed no improvement.
Diagnosis, Differential ; Drug Resistance* ; Gyeonggi-do ; Humans ; Korea ; Mycobacterium ; Mycobacterium bovis ; Mycobacterium chelonae ; Mycobacterium fortuitum ; Mycobacterium tuberculosis ; Nontuberculous Mycobacteria* ; Retrospective Studies ; Soil ; Sputum ; Tuberculosis ; Tuberculosis, Pulmonary* ; Water

Nontuberculous mycobacteria (NTM) are emerging pathogens that affect both immunocompromised and immunocompetent patients. The incidence and prevalence of NTM lung disease are increasing worldwide and rapidly becoming a major public health problem. For the diagnosis of NTM lung disease, patients suspected to have NTM lung disease are required to meet all clinical and microbiologic criteria. The development of molecular methods allows the characterization of new species and NTM identification at a subspecies level. Even after the identification of NTM species from respiratory specimens, clinicians should consider the clinical significance of such findings. Besides the limited options, treatment is lengthy and varies by species, and therefore a challenge. Treatment may be complicated by potential toxicity with discouraging outcomes. The decision to start treatment for NTM lung disease is not easy and requires careful individualized analysis of risks and benefits. Clinicians should be alert to those unique aspects of NTM lung disease concerning diagnosis with advanced molecular methods and treatment with limited options. Current recommendations and recent advances for diagnosis and treatment of NTM lung disease are summarized in this article.
Diagnosis* ; Humans ; Incidence ; Lung Diseases* ; Lung* ; Mycobacterium ; Mycobacterium avium Complex ; Mycobacterium kansasii ; Nontuberculous Mycobacteria ; Prevalence ; Public Health ; Risk Assessment

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

This study investigated the changes in the major etiologic organisms and clinical phenotypes of nontuberculous mycobacterial lung disease (NTM-LD) over a recent 15-year period in Korea. The increase of number of patients with NTM-LD was primarily due to an increase of Mycobacterium avium complex (MAC) lung disease (LD). Among MAC cases, the proportion of M. avium increased compared with M. intracellulare, whereas the incidence of M. abscessus complex and M. kansasii LD remained relatively stable. The proportion of cases of the nodular bronchiectatic form increased compared with the fibrocavitary form of NTM-LD.
Epidemiology ; Humans ; Incidence ; Korea ; Lung Diseases ; Lung ; Mycobacterium avium Complex ; Mycobacterium kansasii ; Nontuberculous Mycobacteria ; Phenotype ; Republic of Korea ; Tertiary Care Centers

As the prevalence of tuberculosis declines, the proportion of nontuberculous mycobacterial (NTM) lung disease is increasing in Korea. The combined use of liquid and solid media increases the sensitivity of mycobacterial culture and shortens culture time. Because NTMs are ubiquitous in the environment, NTM lung disease requires strict diagnostic criteria to prevent over-diagnosis of NTM lung disease. Mycobacterium avium complex is the most common pathogen of NTM lung disease in Korea and present in two forms: upper lobe cavitary and nodular bronchiectatic form. Decision of treatment of NTM lung disease depends on the infecting species and overall condition of the patient. Because medical therapy requires the use of multiple drugs over 18 to 24 months, surgery for localized disease may be useful for those species refractory to medical therapy.
Culture Media ; Humans ; Korea ; Lung Diseases ; Mycobacterium avium Complex ; Mycobacterium avium-intracellulare Infection ; Nontuberculous Mycobacteria ; Prevalence ; Tuberculosis