Clinical Relevance Of Non-tuberculous Mycobacteria Research Articles

Micobacterias no tuberculosas: cuando categorizarlas en pediatría

Background: The term "nontuberculous mycobacteria" refers to more than 170 different species of bacteria that are not Mycobacterium tuberculosis or M. leprae. These bacteria can cause a variety of infections in children. Accurate diagnosis is crucial, as they can be confused with other diseases. Treatment can be challenging due to antibiotic resistance in some strains. The literature review focuses on improving the diagnosis and treatment of these infections in the pediatric population. The characterization of these bacteria, through methods such as PCR, is essential for effective treatment. Material and methods: A systematic review was performed to determine the need to categorize nontuberculous mycobacteria in pediatrics. Various databases and Boolean operators were used to search for relevant information. Inclusion and exclusion criteria were applied to select documents. The review covered the period from 2012 to 2023. They focused on pediatric studies on nontuberculous mycobacteria. Results: The article "Idiopathic CD4+ lymphocytopenia and juvenile laryngeal papillomatosis" describes a case of juvenile laryngeal papillomatosis (JLP) that was complicated by idiopathic CD4 lymphocytopenia (ICL). Despite treatments and surgeries, JLP progressed. The patient developed ICL based on the decrease in CD4+ lymphocytes without HIV. After receiving interferon-alpha with partial response, he died. The study "Prevalence and species spectrum of both pulmonary and extrapulmonary nontuberculous mycobacteria isolates" highlights the high prevalence of nontuberculous mycobacteria in India, especially M. abscessus. "Nontuberculous Mycobacteria in Denmark" evaluates the incidence and clinical relevance of NTM in Denmark from 1991 to 2015, finding a stable incidence and differences in age groups and species. These studies enrich the understanding of these medical conditions. Conclusion: The four studies analyzed offer a global vision of the incidence and characteristics of nontuberculous mycobacteria (NTM) in various regions. Although they all address NTM, they reveal geographic variability in their incidence and characteristics. A global increase in the incidence of NTM is observed, raising concerns about its clinical relevance. Furthermore, the study in New York highlights the increase in NTM in densely populated urban environments. Botswana underlines the importance of accurate diagnosis, especially in areas with high prevalence of tuberculosis and HIV. In Denmark, no significant increase in the incidence of NTM is observed, suggesting regional variability. Together, these findings emphasize the need to understand the local epidemiology of NTM and the importance of its prevention and control

Clinical relevance of pulmonary non-tuberculous mycobacterial isolates in three reference centres in Belgium: a multicentre retrospective analysis

Background/objectivesAssessing the clinical relevance of non-tuberculous mycobacteria (NTM) isolated from respiratory samples can be challenging. The epidemiology and pathogenicity of NTM species vary geographically. We aimed to outline the clinical relevance and associated radiological patterns of NTM species isolated in Belgium.MethodsWe performed a retrospective multicentre analysis of all patients identified from the laboratory database with > 1 respiratory sample growing NTM from January 2010 through December 2017. We collected clinical, radiological and microbiological data through medical record review and assessed clinical relevance according to ATS/IDSA criteria for NTM pulmonary disease (NTM-PD).ResultsOf the 384 unique patients, 60% were male, 56% had a smoking history and 61% had pre-existing lung disease. Mycobacterium avium complex (MAC), M. gordonae and M. xenopi were the most frequently isolated species: 53, 15 and 8% respectively. 43% of patients met ATS/IDSA criteria, of whom 28% presented with fibrocavitary disease. Weight loss, fever, nodular bronchiectatic and fibrocavitary lesions on chest CT, and a positive acid-fast bacilli (AFB) stain were significantly associated with NTM-PD. The species with the highest pathogenic potential were M. abscessus (11/12), M. malmoense (6/7) and M. intracellulare (41/64).ConclusionIn our study, MAC was the most commonly isolated NTM species, but M. abscessus and M. malmoense showed the highest probability of being clinically relevant. Clinical relevance varied not only by species but also by radiological findings on chest CT and AFB staining. Clinicians should consider these elements in their treatment decision making. Prospective data including clinical outcome are needed to provide more robust evidence.

Clinical relevance of non-tuberculous mycobacteria isolated from respiratory specimens: seven year experience in a UK hospital

The frequency of isolation of non-tuberculous mycobacteria (NTM) species from respiratory specimens is increasing, however the clinical relevance of such identifications vary by mycobacterial species and geographical location. A retrospective study of 853 NTM isolates from respiratory samples from 386 patients over seven years was performed. Clinical records and radiographic information were examined. Clinical significance was assessed by American Thoracic Society diagnostic criteria. 25% of all patients with respiratory isolates met criteria for non-tuberculous mycobacterial pulmonary disease (NTM-PD). Significant symptoms were weight loss, fever, night sweats, productive cough and haemoptysis. HIV co-infection was a significant risk factor for disease. Cavities, nodules and tree-in-bud were significant radiographic findings. Mycobacterium avium complex (MAC) were the dominant species isolated from this patient cohort. Mycobacterium abscessus (M. abscessus) was the species most likely to cause clinically significant disease and be sputum smear positive, thus warranting particular attention.

Pulmonary isolation and clinical relevance of nontuberculous mycobacteria during nationwide survey in Serbia, 2010-2015.

The rates of pulmonary colonization and disease due to nontuberculous mycobacteria (NTM) appear to be increasing globally, but diversity of species recovered as well as clinical relevance of NTM isolates differ considerably by geographic region. The first nationwide study of isolation frequency and clinical significance of NTM in Serbia included all patients with respiratory specimens yielding a positive NTM culture over the six-year period, 2010–2015. We analyzed trends in annual NTM isolation and NTM pulmonary disease (PD) incidence rates, with NTM PD cases defined in accordance with microbiological criteria established by the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA). 777 pulmonary NTM isolates were collected from 565 patients, of whom 126 (22.3%) met the ATS/IDSA criteria. The annual NTM isolation and NTM PD incidence rates per 100,000 changed over 2010–2015 from 0.9 to 1.6 (p = 0.1746) and from 0.18 to 0.48 (p = f0.0040), respectively. Both isolation and disease rates increased considerably with age, while higher NTM PD rates were also associated with residence in urbanized areas. Diversity of NTM species isolated was shown to be region-specific, with M. xenopi as the most prevalent species (17.3%), and increasing isolation rates of rapid growing mycobacteria (RGM) (p = 0.0072). M. xenopi was also the most common cause of NTM PD (28.6%), followed by RGM (27.8%). With 73% clinically relevant isolates, M. abscessus was identified as the most clinically relevant NTM species. While NTM PD obviously remains a rare disease in Serbia, the overall results justify recognition of NTM as pathogens of rising importance, and require further characterization of their epidemiology in the country.

Emergence of Rare Species of Nontuberculous Mycobacteria as Potential Pathogens in Saudi Arabian Clinical Setting.

BackgroundClinical relevance of nontuberculous mycobacteria (NTM) is increasing worldwide including in Saudi Arabia. A high species diversity of NTM’s has been noticed in a recent study. However, the identification in diagnostic laboratories is mostly limited to common species. The impact of NTM species diversity on clinical outcome is so far neglected in most of the clinical settings.Methodology/Principal FindingsDuring April 2014 to September 2015, a nationwide collection of suspected NTM clinical isolates with clinical and demographical data were carried out. Primary identification was performed by commercial line probe assays. Isolates identified up to Mycobacterium species level by line probe assays only were included and subjected to sequencing of 16S rRNA, rpoB, hsp65 and 16S-23S ITS region genes. The sequence data were subjected to BLAST analysis in GenBank and Ez-Taxon databases. Male Saudi nationals were dominated in the study population and falling majorly into the 46–59 years age group. Pulmonary cases were 59.3% with a surprising clinical relevance of 75% based on American Thoracic Society guidelines. Among the 40.7% extra-pulmonary cases, 50% of them were skin infections. The identification revealed 16 species and all of them are reporting for the first time in Saudi Arabia. The major species obtained were Mycobacterium monascence (18.5%), M. cosmeticum (11.1%), M. kubicae (11.1%), M. duvalli (7.4%), M.terrae (7.4%) and M. triplex (7.4%). This is the first report on clinical relevance of M. kubicae, M. tusciae, M.yongonense, M. arupense and M.iranicum causing pulmonary disease and M. monascence, M. duvalli, M. perigrinum, M. insubricum, M. holsaticum and M. kyorinense causing various extra-pulmonary diseases in Saudi Arabia. Ascites caused by M. monascence and cecum infection by M. holsaticum were the rarest incidents.Conclusions/SignificanceTo the first time in the country, clinical significance of various rare NTM’s are well explored and the finding warrants a new threat to the Saudi Arabian clinical settings.

Clinical Significance of Nontuberculous Mycobacteria Isolated From Respiratory Specimens in a Chinese Tuberculosis Tertiary Care Center.

The clinical relevance of non-tuberculous mycobacteria (NTM) has been reported to be different dramatically by species or by regions, however, no such evaluation has been performed in China.A retrospective study was performed in Beijing Chest Hospital. All the NTM strains isolated from respiratory specimens in the past 5 years, and patients’ clinical records (symptoms and radiographic information etc.) were investigated. The clinical relevance was evaluated according to the criteria recommended by the American Thoracic society. Totally 232 NTM strains were recruited, among them, M. intracellulare was the dominant species (40.5%), followed by M. abscessus (28.4%). 109 patients, with 185 total isolates, had full clinical records available for review. 84.4% (38/45), 85.7% (24/28%) and 63.6% (7/11) of patients with isolation of M. intracellulare, M. abscessus and M. kansasii, respectively, were categorized as definite NTM disease. Whereas all the 10 patients with isolation of M. gordonae were defined as unlikely NTM disease. The majority of NTMs isolates yielded from respiratory specimens in Beijing Chest Hospital were clinically significant, and M. intracellulare and M. abscessus was the dominated species of NTM lung disease. NTM lung infections demonstrated some specific chest radiograph characteristics.

Drug resistance and its clinical relevance of nontuberculous mycobacteria in Sichuan area

Objective To analyze the status of infection and drug resistance of nontuberculous mycobacteria (NTM) and its clinical relevance in Sichuan area. Methods Mycobacteria laboratory specimens from January 2014 to December 2015 in Public Health Clinical Center of Chengdu were retrospectively collected and analyzed. NTM identification was performed by gene chip or 16S rDNA gene sequencing. Drug susceptibility test of NTM was performed using proportion method. Clinical relevance of 87 NTM isolates from patients was analyzed. The chi-square test was used for rates comparison between groups. Results There were 12 460 cases of Mycobacterium culture from January 2014 to December 2015. A total of 3 991 cases (32.0%) were positive for culture and 125 cases of them were nontuberculous mycobacteria. Nine species/complex of NTM were identified. M. chelonae/M. abscessus was the predominant species (42/125, 33.6%), followed by M. intracellulare (37/125, 29.6%) and M. avium (29/125, 23.2%). There was no statistically significant difference of drug resistance within two years (χ2=3.88, P>0.05). All 125 NTM isolates exhibited different degrees of drug resistance to anti-TB drugs. The rate of isoniazid resistance (99.2%) was the highest, followed by rifampicin (97.6%), streptomycin (93.6%), ofloxacin (89.6%), amikacin (85.6%), capreomycin (81.6%), ethambutol (65.6%), kanamycin (58.4%) and clarithromycin (44.8%). Of the 87 NTM isolates from patients, 58 cases (66.7%) were diagnosed with NTM infection. Conclusions The incidence of NTM shows an upward trend during the period from 2014 to 2015 in Sichuan area, and the drug resistance is severe. The clinical relevance of NTM isolations needs further study. Key words: Mycobacterium; Nontuberculous; Drug resistance; Clinical relevance

Geographical distribution and clinical relevance of non-tuberculous mycobacteria in Croatia

The clinical relevance of non-tuberculous mycobacteria (NTM) in Croatia is unknown. To estimate the isolation rate of NTM, record geographical differences and assess the burden of pulmonary NTM disease in Croatia. Nationwide retrospective cohort study of all Croatian residents with NTM isolated by culture in the period from 2006 to 2010. Microbiological criteria of the American Thoracic Society were used to establish a laboratory-based case definition of possible and probable NTM disease. Of 1187 individuals with pulmonary NTM isolates, 8.6% met the possible and 5.5% met the probable disease criteria. We estimated an annual incidence of probable pulmonary NTM disease of 0.23 per 100,000 population. This estimated annual incidence was 0.35/100,000 in the coastal region and 0.17/100,000 in the continental region. Species distribution differed between coastal and continental Croatia. NTM isolation frequency increased over the study period. Geography plays an important role in NTM species distribution and possible disease. The overall burden of NTM pulmonary disease in Croatia is still low compared to that of tuberculosis, but it is higher in the coastal region compared to the continental region.

Clinical relevance of non-tuberculous mycobacteria isolated in the Nijmegen-Arnhem region, The Netherlands

Background:The frequency of clinical isolation of non-tuberculous mycobacteria (NTM) in the Netherlands is increasing, but its clinical relevance is often uncertain.Objective:To assess the frequency and clinical relevance of isolation of...

Clinical Relevance of Nontuberculous Mycobacteria, Oman

Little is known about the clinical relevance of nontuberculous mycobacteria (NTM) in the Arabian Peninsula. We assessed the prevalence and studied a random sample of isolates at a reference laboratory in Muscat, Oman. NTM cause disease in this region, and their prevalence has increased.

Nontuberculous Mycobacteria, Zambia

Clinical relevance of nontuberculous mycobacteria (NTM) isolated from 180 chronically ill patients and 385 healthy controls in Zambia was evaluated to examine the contribution of these isolates to tuberculosis (TB)-like disease. The proportion of NTM-positive sputum samples was significantly higher in the patient group than in controls; 11% and 6%, respectively (p<0.05). NTM-associated lung disease was diagnosed for 1 patient, and a probable diagnosis was made for 3 patients. NTM-positive patients and controls were more likely to report vomiting and diarrhea and were more frequently underweight than the NTM-negative patients and controls. Chest radiographs of NTM-positive patients showed deviations consistent with TB more frequently than those of controls. The most frequently isolated NTM was Mycobacterium avium complex. Multiple, not previously identified mycobacteria (55 of 171 NTM) were isolated from both groups. NTM probably play an important role in the etiology of TB-like diseases in Zambia.