Nontuberculous Mycobacteria Disease Research Articles

Biofilm prevention concentration of clarithromycin against clinically relevant species of nontuberculous mycobacteria.

Mycobacterium avium complex (MAC) and Mycobacterium abscessus are a group of nontuberculous mycobacteria (NTM) that have been described as human pathogens. Their ability to develop biofilms in tissues and medical devices is one of the most important pathogenicity factors, with important implications in diagnosis and treatment. Macrolides are usually considered one of the bases of this treatment. Here we have studied the biofilm prevention concentration (BPC) of 16 strains (n=16) with clarithromycin to avoid the biofilm development by these NTM. In this study, all M. abscessus strains have similar BPC, while MAC strains showed different values. For MAC the concentrations ranged between 1-16 mg/L, while for M. abscessus the concentration was 32 mg/L for all strains except one that was 64 mg/L. These results open the possibility of using macrolides for the prevention of biofilm development in patients with a risk of developing NTM disease.

Biofilm Formation in Mycobacterial Genus; Mechanism of Biofilm Formation and Anti-Mycobacterial Biofilm Agents.

Mycobacterium tuberculosis, Mycobacterium leprae, and non-tuberculous mycobacteria (NTM) are among the most significant human pathogens within the Mycobacterium genus. These pathogens can infect people who come into contact with biomaterials or have chronic illnesses. A characteristic pathogenic trait of mycobacteria is the development of biofilms, which involves several molecules, such as the GroEL1 chaperone, glycopeptidolipids, and shorter-chain mycolic acids. Bacterial behavior is influenced by nutrients, ions, and carbon sources, which also play a regulatory role in biofilm development. Compared to their planktonic phase, mycobacterial biofilms are more resilient to environmental stresses and disinfectants. Mycobacteria that produce biofilms have been found in several environmental studies, particularly in water systems. NTM can cause respiratory problems in individuals with underlying illnesses such as cystic fibrosis, bronchiectasis, and old tuberculosis scars. Mycobacteria that grow slowly, like those in the Mycobacterium avium complex (MAC), or rapidly, like Mycobacterium abscessus, can be pathogens. Infections related to biomaterials represent a significant category of biofilm-associated infections, with rapidly growing mycobacteria being the most frequently identified organisms. A biofilm produced by M. tuberculosis can contribute to caseous necrosis and cavity formation in lung tissue. Additionally, M. tuberculosis forms biofilms on clinical biomaterials. Biofilm formation is a major contributor to antimicrobial resistance, providing defense against drugs that would typically be effective against these bacteria in their planktonic state. The antibiotic resistance of biofilm-forming microbes may render therapy ineffective, necessitating the physical removal of biofilms to cure the infection. Recently, new approaches have been developed with potential anti-biofilm compounds to increase treatment effectiveness. Understanding biofilms is crucial for the appropriate treatment of various NTM diseases, and the recent discovery of M. tuberculosis biofilms has opened up a new field of study. This review focuses on the biofilm formation of the Mycobacterial genus, the mechanisms of biofilm formation, and anti-mycobacterial biofilm agents.

Nationwide Increasing Incidence of Nontuberculous Mycobacterial Diseases Among Adults in Denmark: Eighteen Years of Follow-Up

BackgroundThe epidemiology of nontuberculous mycobacteria (NTM) infections is not well described. In this study, we determined the incidence and prevalence of NTM infections and focused on social risk factors. Additionally, we described persons suffering from pulmonary and extrapulmonary NTM. Research questionWhat is the incidence and prevalence of NTM and what are the characteristics of the affected patients? MethodsThis is a nationwide retrospective register-based cohort study in Denmark. Adult patients with NTM diagnosis in the Danish national registers from 2000-2017 were classified as having either pulmonary or extrapulmonary NTM disease. ResultsWe identified 1,146 adults with an NTM diagnosis. 661 patients had pulmonary NTM of which 50.4% were male, while 485 had extrapulmonary NTM of which 59.6% were male. The median age (Interquartile range), was 66 years (18) and 57 years (32), respectively. The yearly incidence rate per 100,000 increased between 2000 and 2017 for both pulmonary (0.4 to 1.3) and extrapulmonary NTM (0.3 to 0.6). The annual prevalence per 100,000 increased from 0.4 to 3.5 for pulmonary and 0.3 to 1.0 for extrapulmonary NTM. The incidence rate increased with age. The incidence of pulmonary NTM was highest in 70+ year-olds (19.3 per 100,000). Compared to pulmonary NTM patients, extrapulmonary NTM patients were more likely to be employed and had a higher educational level. InterpretationThe prevalence of NTM disease in Denmark increased between 2000 and 2017. Pulmonary and extrapulmonary NTM patients are two distinct groups that differ in age, gender, education, and employment status. Increased suspicion of pulmonary NTM disease is warranted in the elderly after exclusion of more common lung infections.

Therapeutic developments for tuberculosis and nontuberculous mycobacterial lung disease.

Tuberculosis (TB) drug discovery and development has undergone nothing short of a revolution over the past 20 years. Successful public-private partnerships and sustained funding have delivered a much-improved understanding of mycobacterial disease biology and pharmacology and a healthy pipeline that can tolerate inevitable attrition. Preclinical and clinical development has evolved from decade-old concepts to adaptive designs that permit rapid evaluation of regimens that might greatly shorten treatment duration over the next decade. But the past 20 years also saw the rise of a fatal and difficult-to-cure lung disease caused by nontuberculous mycobacteria (NTM), for which the drug development pipeline is nearly empty. Here, we discuss the similarities and differences between TB and NTM lung diseases, compare the preclinical and clinical advances, and identify major knowledge gaps and areas of cross-fertilization. We argue that applying paradigms and networks that have proved successful for TB, from basic research to clinical trials, will help to populate the pipeline and accelerate curative regimen development for NTM disease.

Non-tuberculous mycobacteria hybridisation profiles in the GenoType MTBDRplus assay: experience from a diagnostic routine of a high-throughput laboratory.

Introduction. Disease caused by non-tuberculous mycobacteria (NTM) is an emergent problem. Because NTM pulmonary disease and tuberculosis (TB) have similar clinical presentations, many cases of NTM may be misdiagnosed as TB before laboratory identification of the NTM species.Hypothesis/Gap Statement. Clinical laboratories should always perform differentiation between Mycobacterium tuberculosis complex (MTBC) and NTM to guide patients' correct treatment.Aim. To describe the characteristics and to identify mycobacterial isolates presumptively classified as MTBC by macroscopic characteristics in culture media that tested negative in GenoType MTBDRplus.Methodology. All cultures from February 2019 to December 2021 showing MTBC macroscopic characteristics were processed by GenoType MTBDRplus. MTBC-negative cultures underwent species identification by immunochromatography, line probe assays and PRA-hsp65. Patients' data were obtained from Brazilian surveillance systems.Results. Only 479 (3.1%) of 15 696 isolates presumptively identified as MTBC were not confirmed by GenoType MTBDRplus and were then subjected to identification. A total of 344 isolates were shown to be NTM, of which 309 (64.5%) and 35 (7.3%) were identified to the species and genus levels, respectively. Of the 204 NTM isolates with MTBC characteristics, the most frequent species were M. fortuitum (n=52, 25.5%), M. abscessus complex (MABC; n=27, 13.2%) and M. avium complex (MAC; n=26, 12.7%). Regarding the GenoType MTBDRplus results from NTM isolates, there were diverse hybridisation profiles with rpoB gene's different wild-type (WT) probes. Seventy-six (16.1%) of the 473 patients were classified as having NTM disease, the most frequent being MAC (n=15, 19.7%), MABC (n=13, 17.1%), M. kansasii (n=10, 13.2%) and M. fortuitum (n=6, 7.9%).Conclusion. Because the signs and symptoms of pulmonary TB are similar to those of pulmonary mycobacteriosis and treatment regimens for TB and NTM are different, identifying the disease-causing species is paramount to indicate the correct management. Thus, in the laboratory routine, when an isolate presumptively classified as MTBC is MTBC-negative, it is still essential to perform subsequent identification.

Sudapyridine (WX-081) antibacterial activity against Mycobacterium avium, Mycobacterium abscessus, and Mycobacterium chelonae in vitro and in vivo.

Due to the rapidly increased cases globally, non-tuberculous mycobacteria (NTM) disease has become a significant public health problem. NTM accounted for 11.57% of all mycobacterial isolates in China, with a high detection rate of Mycobacterium abscessus, Mycobacterium avium, and Mycobacterium chelonae during 2000-2019. Treatment of NTM infection is often challenging, as natural resistance to most antibiotics is quite common among different NTM species. Hence, identifying highly active anti-NTM agents is a priority for potent regimen establishment. The pursuit of new drugs to treat multidrug-resistant tuberculosis may also identify some agents with strong activity against NTM. Sudapyridine (WX-081) is a structural analog of bedaquiline (BDQ), which was developed to retain the anti-tuberculosis efficacy but eliminates the severe side effects of BDQ. This study initially evaluated the antimicrobial activity of this novel compound against M. avium, M. abscessus, and M. chelonae in vitro, in macrophages and mice, respectively.

Common Features of Environmental Mycobacterium chelonae from Colorado Using Partial and Whole Genomic Sequence Analyses

Nontuberculous mycobacteria (NTM) are environmentally acquired opportunistic pathogens that cause chronic lung disease in susceptible individuals. While presumed to be ubiquitous in built and natural environments, NTM environmental studies are limited. While environmental sampling campaigns have been performed in geographic areas of high NTM disease burden, NTM species diversity is less defined among areas of lower disease burden like Colorado. In Colorado, metals such as molybdenum have been correlated with increased risk for NTM infection, yet environmental NTM species diversity has not yet been widely studied. Based on prior regression modeling, three areas of predicted high, moderate, and low NTM risk were identified for environmental sampling in Colorado. Ice, plumbing biofilms, and sink tap water samples were collected from publicly accessible freshwater sources. All samples were microbiologically cultured and NTM were identified using partial rpoB gene sequencing. From these samples, areas of moderate risk were more likely to be NTM positive. NTM recovery from ice was more common than recovery from plumbing biofilms or tap water. Overall, nine different NTM species were identified, including clinically important Mycobacterium chelonae. MinION technology was used to whole genome sequence and compare mutational differences between six M. chelonae genomes, representing three environmental isolates from this study and three other M. chelonae isolates from other sources. Drug resistance genes and prophages were common findings among environmentally derived M. chelonae, promoting the need for expanded environmental sampling campaigns to improve our current understanding of NTM species abundance while opening new avenues for improved targeted drug therapies.

NONTUBERCULOUS MYCOBACTERIA - CURRENT RISK IN BULGARIA

Background: Nontuberculous mycobacteria (NTM) are generally free-living and have a potential to cause opportunistic infection. More than 190 species of NTM have been identified (http://www.bacterio.net/mycobacterium.html), up to 60 species of them are pathogenic. The distribution is geographically specific for some species and others are cosmopolitan. Understanding their diversity has practical value for the treatment and management of NTM disease. Except for isolated reports, there is no accurate information about NTM spread among Bulgarian patients. Material and Methods: We retrospectively analysed the data on the NTM isolated from patients throughout the country for the period from January 2010 to December 2017. Identification to the species level was done by Line Probe Assay (LPA). Results: 586 NTM strains were identified. We calculated the rate of NTM isolation in Bulgaria and NTM disease incidence by applying microbiological criteria defined by the American Thoracic Society (ATS). As a result, the laboratory isolation rate amounted to 1/100 000 people for the period, and when applying only the ATS criteria, the prevalence of NTM disease was 0,23 per 100 000 people. In both cases, we reported that NTM   disease incidence remains low as compared to tuberculosis, though with an increasing  trend. The prevalence of NTM varied significantly between northern and southern Bulgaria, as well as between the capital and the rest of the country's regions. Conclusions: Slow growing NTM species predominate in Bulgaria but rapidly growing ones have isolation levels higher than the average for Europe and closer to that of Asian countries. Given the demographic situation in Bulgaria and the changing climatic factors, NTM infections need special attention.

Disseminated Infection by Scedosporium/Lomentospora During Induction Therapy for Acute Myeloid Leukemia Complicated by Nontuberculous Mycobacteria.

Scedosporium/Lomentospora infections are rare and are associated with a high mortality rate in immunocompromised patients. A 69-year-old man with nontuberculous mycobacteria (NTM) died during induction chemotherapy for acute myeloid leukemia because of multiple organ failure due to pneumonia. During an autopsy, Lomentospora prolificans was detected using a fungal gene analysis of the blood, lungs, spleen, kidneys, and intestines, and Scedosporium aurantiacum was detected in the lungs. NTM disease may predispose patients to Scedosporium/Lomentospora infections. Physicians should consider Scedosporium/Lomentospora spp. as an invasive fungal infection that occurs during myelosuppression, particularly when NTM is a complication.

Intracellular iron accumulation facilitates mycobacterial infection in old mouse macrophages

Aging has a significant impact on the immune system, leading to a gradual decline in immune function and changes in the body’s ability to respond to bacterial infections. Non-tuberculous mycobacteria (NTM), also known as atypical mycobacteria or environmental mycobacteria, are commonly found in soil, water, and various environmental sources. While many NTM species are considered opportunistic pathogens, some can cause significant infections, particularly in individuals with compromised immune systems, such as older individuals. When mycobacteria enter the body, macrophages are among the first immune cells to encounter them and attempt to engulf mycobacteria through a process called phagocytosis. Some NTM species, including Mycobacterium avium (M. avium) can survive and replicate within macrophages. However, little is known about the interaction between NTM and macrophages in older individuals. In this study, we investigated the response of bone marrow–derived macrophage (BMMs) isolated from young (5 months) and old (25 months) mice to M. avium serotype 4, one of the main NTM species in patients with pulmonary NTM diseases. Our results demonstrated that BMMs from old mice have an increased level of intracellular iron and are more susceptible to M. avium serotype 4 infection compared to BMMs from young mice. The whole-cell proteomic analysis indicated a dysregulated expression of iron homeostasis–associated proteins in old BMMs regardless of mycobacterial infection. Deferoxamine, an iron chelator, significantly rescued mycobacterial killing and phagolysosome maturation in BMMs from old mice. Therefore, our data for the first time indicate that an intracellular iron accumulation improves NTM survival within macrophages from old mice and suggest a potential application of iron-chelating drugs as a host-directed therapy for pulmonary NTM infection in older individuals.

Incorporating direct molecular diagnostics in management algorithms for nontuberculous mycobacteria: Is it high time?

Nontuberculous mycobacteria (NTM) are a group of acid-fast mycobacteria other than Mycobacterium tuberculosis complex (MTBC) that cause pulmonary disease that is similar to the disease caused by MTBC. International guidelines for the diagnosis of pulmonary NTM disease are rigid and have remained unchanged for nearly 2 decades. In this opinion piece, we provide a new perspective on the traditional criteria by suggesting a diagnostic algorithm that incorporates direct molecular identification of NTM performed on raw sputum specimens (using Sanger or targeted deep sequencing approaches, among others) paired with traditional culture methods. Our approach ensures a more rapid diagnosis of pulmonary NTM disease, thus, facilitating timeous clinical diagnosis, and prompt treatment initiation, where indicated, and leverages recent advances in novel molecular techniques into routine NTM identification practice.

The performance of interferon gamma release assays in patients with nontuberculous mycobacterial infection: a systematic review and meta-analysis.

The actual positive rate of interferon gamma release assays (IGRAs) in patients with nontuberculous mycobacteria (NTM) infections remains unclear. This review and meta-analysis present the prevalence of positive IGRAs (T-SPOT.TB and QuantiFERON [QFT] tests) among patients infected with NTM isolates (with or without ESAT-6/CFP-10). Several databases, including PubMed, Scopus, Embase, and Web of Science were searched (until June 18th, 2022). Studies that had the following data were included: (1) results of T-SPOT.TB, QuantiFERON (QFT) test, or both, (2) NTM species, and (3) NTM diseases, or NTM colonization. The metaprop command that incorporates a Freeman-Tukey double arcsine transformation is used for pooling proportions. A total of 11 articles (n = 929) were deemed eligible for inclusion. Meta-analysis identified that the overall pooled positive and indeterminate rates of IGRA results in patients with NTM infections was 16% and 5%, respectively. Subgroup analysis showed that the positive rate of IGRAs in patients infected with NTM (without ESAT-6/CFP-10) was 7% (95% CI, 1%-18%), and 44% (95%CI, 22%-68%) in patients infected with NTM (with ESAT-6/CFP-10). In addition, the indeterminate rate of QFT (7%, 95% CI: 4%-12%) was higher than that of T-SPOT.TB (0%; 95% CI, 0%-2%) among the overall population with NTM infections. The IGRAs have a moderate positive rate for the diagnosis of NTM (expressing ESAT-6/CFP-10) infections, and a significant indeterminate rate is observed among the overall population infected with NTM. However, these findings should be interpreted with caution because of the high heterogeneity among studies.

Prospective evaluation of nontuberculous mycobacteria disease in cystic fibrosis: The design of the PREDICT study

BackgroundNontuberculous mycobacteria (NTM) are an important cause of airway infections in people with cystic fibrosis (pwCF). Isolation of NTM from respiratory specimens of pwCF do not mandate treatment in the absence of clinical and radiologic features of NTM pulmonary disease (NTM-PD), as some pwCF clear the infection without treatment and others do not appear to progress to NTM-PD despite persistent infection. An evidence-based protocol to standardize diagnosis of NTM-PD is needed to systematically identify pwCF who may benefit from treatment. MethodsIn this multicenter observational study, eligible pwCF who are 6 years of age and older and who have had a recent positive NTM culture are systematically evaluated for NTM-PD. Participants are identified based on positive NTM culture results obtained during routine clinical care and following enrollment are evaluated for NTM-PD and CF-related comorbidities. Participants are followed in PREDICT until they meet NTM-PD diagnostic criteria and are ready to initiate NTM treatment, or until study termination. Active participants who have not met these criteria are re-consented every 5 years to enable long-term participation. ResultsThe primary endpoint will summarize the proportion of participants who meet the NTM-PD diagnosis definition. The time from enrollment to NTM-PD diagnosis will be derived from Kaplan-Meier estimates. ConclusionA prospective protocol to identify NTM-PD in pwCF will test if this standardized approach defines a cohort with signs and symptoms associated with NTM-PD, to assist with clinical decision making and to build a framework for future therapeutic trials. Trial RegistrationClinicalTrials.gov Identifier: NCT02073409

Nontuberculous mycobacterial infections in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation.

The incidence of mycobacterial infections in patients with hematologic malignancies and hematopoietic stem cell transplant (HSCT) recipients is increasing, contributing to significant mortality and morbidity. This review explores the epidemiology, risk factors, clinical presentation, diagnosis, and treatment of nontuberculous mycobacteria (NTM) in this population. A literature search was performed using PubMed with keywords and MeSH terms pertaining to the topics of nontuberculous mycobacteria, hematologic malignancies, hematopoietic stem cell transplant, cellular therapies, chimeric antigen therapies, epidemiology, diagnosis, and treatment. Additionally, we examined the reference lists of the included articles to identify other pertinent studies. Diagnosing mycobacterial disease among patients with hematologic disease and treatment-associated immunosuppressive conditions is challenging due to the lack of distinctive clinical, radiographic, and laboratory markers, as well as the atypical manifestations compared to immunocompetent patients. Treatment involves using a combination of antibiotics for extended durations, coupled with strategies to achieve source control and reduce immunosuppression when feasible. This is complicated by the absence of clear data correlating in-vitro drug susceptibility and clinical outcome for many antimicrobials use to treat NTM, adverse drug-drug interactions, and the frequent challenges related to poor medication tolerability and toxicities. The rising incidence and corresponding clinical challenges of mycobacterial infections in this unique patient population necessitate a heightened awareness and familiarity of NTM disease by clinicians to achieve timely diagnosis and favorable treatment outcomes.

Epidemiology of non-tuberculous mycobacterial diseases in Slovakia during the years 2016–2021

Nontuberculous mycobacteria (NTM) are opportunistic human pathogens found worldwide, primarily in the environment. They predominantly affect the lungs, especially in individuals with compromised immune systems. Recent studies suggest an increasing incidence of NTM disease; however, their actual clinical impact in Slovakia remains uncertain. In this study, we conducted a retrospective analysis using a representative collection of NTM cases in the country. We searched the national database for patients with positive NTM cultures between January 2016 and December 2021. A total of 1355 NTM-positive cultures were identified in Slovakia, with no significant increase observed during the study period. Among these, 358 cases (26.4%) were confirmed as NTM disease. The incidence of the disease was notably higher in individuals over 55 years old (p < 0.0001). Moreover, women diagnosed with NTM disease exhibited a significantly higher average age than men (p = 0.0005). The majority of NTM disease cases were attributed to Mycobacterium (M.) intracellulare (39.9%) and M. avium (38.5%). Geographically, the highest incidence of NTM disease was observed in the Bratislava region (10.69 per 100,000 population).

A Case Series of Non-Tuberculous Mycobacterial Pulmonary Disease Masquerading as Malignancy From a Community-Based Hospital

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms in the environment that can potentially cause a range of pulmonary and extrapulmonary infections in humans. Epidemiological risk factors and the host’s immune status determine the susceptibility to various clinical syndromes caused by different NTM species. Non-tuberculous mycobacteria pulmonary disease (NTM-PD) is primarily reported in patients with underlying lung disease. These infections often pose a significant disease burden on affected patients as they are often chronic, difficult to treat, and necessitate long-term multi-drug therapy. Mycobacterium avium complex (MAC) is the most common causative pathogen of NTM-PD in the USA, followed by Mycobacterium kansasii ( M. kansasii ). Less common species in the USA include Mycobacterium xenopi ( M. xenopi ), Mycobacterium abscessus , and others, largely depending upon the geographic location and exposure to species-specific predisposing risks. In this case series, the authors report on three elderly patients with chronic lung diseases who had pulmonary NTM disease caused by M. xenopi and MAC. The patients were encountered in both inpatient and outpatient settings from a community-based hospital in the midwestern USA. The clinical and radiological features of NTM-PD masqueraded as malignancy and posed a diagnostic dilemma. The epidemiology, clinical and radiological features, diagnosis, and management of NTM-PD are reviewed in this report. J Med Cases. 2023;14(4):141-147 doi: https://doi.org/10.14740/jmc4098

Risk factors and outcomes of non-tuberculous mycobacteria infection in lung transplant recipients: A systematic review and meta-analysis

Patients with structural lung disease and immunocompromised status are at increased risk of pulmonary non-tuberculous mycobacteria (NTM) infection. However, literature on NTM in lung transplant recipients (LTR) is limited. We sought to systematically review the literature and perform a meta-analysis to examine associations with NTM disease and isolation in LTRs and their influence on mortality and chronic lung allograft dysfunction (CLAD). A literature search of MEDLINE and Embase was performed on February 23, 2022. NTM disease was defined according to international guidelines. Isolation was defined as any growth of NTM in culture. Odds ratios (OR) were pooled for risk factors of NTM disease or isolation, and hazard ratios (HR) were pooled for mortality or CLAD. Eleven studies totaling 3,371 patients were eligible for inclusion, 10 of which underwent meta-analysis. Cystic fibrosis (OR 1.84, 95% confidence interval [CI] 1.03-3.30; I2=0%) and pre-transplant NTM isolation (OR 2.40, 95% CI 1.20-4.83; I2=0%) were associated with NTM disease. Only male sex was associated with NTM isolation (OR 1.45, 95% CI 1.01-2.10; I2=0%). NTM disease was associated with increased mortality (HR 2.69, 95% CI 1.70-4.26; I2=0%) and CLAD (HR 2.11, 95% CI 1.03-4.35; I2=44%). NTM isolation was not associated with mortality in pooled analysis or CLAD in 1 included study. NTM disease, but not isolation, is associated with worse outcomes. Several factors were associated with development of NTM disease, including cystic fibrosis and pretransplant NTM isolation. Strategies to optimize prevention and treatment of NTM disease in lung transplant recipients are needed.

Rapid and Comprehensive Identification of Nontuberculous Mycobacteria.

Next-generation sequencing is a powerful tool to accurately identify pathogens. The MinION sequencer is best suited for the rapid identification of bacterial species due to its real-time sequence output. In this chapter, we introduce a method to identify nontuberculous mycobacteria (NTM) in one sequencing analysis from culture isolates using the MinION sequencer. NTM disease is now recognized as a growing global health concern due to its increasing incidence and prevalence. There are over 200 NTM species, of which the major pathogens are further classified into many subspecies showing different antibiotic susceptibilities. Therefore, identifying the pathogens at the subspecies level of NTM is necessary to select an appropriate treatment regimen. The protocol described here includes DNA extraction by lysis using silica beads, library preparation, sequencing by the MinION sequencer, and analysis of multilocus sequence typing using the software "mlstverse" and enables rapid and comprehensive identification of 175 species of NTM at the subspecies level with high sensitivity and accuracy.

Performance Evaluation of MolecuTech REBA Myco-ID Using HybREAD480 for Identification of Nontuberculous Mycobacteria.

Rapid and accurate identification of nontuberculous mycobacteria (NTM) species is essential for the diagnosis and treatment of NTM disease. MolecuTech REBA Myco-ID (YD Diagnostics, Yongin, Korea) is a line probe assay for identification of NTM species and can be performed using HybREAD480, an instrument for automating the post-PCR steps. In this study, we assessed the performance of MolecuTech REBA Myco-ID using HybREAD480. Seventy-four reference strains, including 65 Mycobacterium strains and nine non-Mycobacterium strains within the order Mycobacteriales, were used to determine the analytical specificity of MolecuTech REBA Myco-ID. The clinical performance of this assay was evaluated with 192 clinical Mycobacterium strains, and the assay results were compared to those of multigene sequencing-based typing. The accuracy of MolecuTech REBA Myco-ID for the 74 reference strains and 192 clinical strains was 77.0% (57/74; 95% confidence interval [CI], 65.8 - 86.0%) and 94.3% (181/192; 95% CI, 90.0 - 97.1%), respectively. Although some rarely isolated NTM species are misidentified, the most commonly isolated NTM species, including M. avium complex, M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. fortuitum com-plex, were all correctly identified. Of note, all M. lentiflavum strains tested (reference strain, n = 1; clinical strain, n = 10) were misidentified as M. gordonae. MolecuTech REBA Myco-ID using HybREAD480 was accurate for identifying commonly isolated NTM species and for discriminating between M. abscessus subsp. abscessus and M. abscessus subsp. massiliense. However, the main limitations of this assay, including misidentification of some rarely isolated NTM species and cross-reactivity between M. lentiflavum and M. gordonae, should be considered.

Diagnosis and Management of Pulmonary NTM with a Focus on Mycobacterium avium Complex and Mycobacterium abscessus: Challenges and Prospects.

Nontuberculous mycobacteria (NTM) are ubiquitous. NTM can affect different organs and may cause disseminated diseases, but the pulmonary form is the most common form. Pulmonary NTM is commonly seen in patients with underlying diseases. Pulmonary Mycobacterium avium complex (MAC) is the most common NTM disease and M. abscessus (MAB) is the most challenging to treat. This review is prepared with the following objectives: (a) to evaluate new methods available for the diagnosis of pulmonary MAC or MAB, (b) to assess advances in developing new therapeutics and their impact on treatment of pulmonary MAC or MAB, and (c) to evaluate the prospects of preventive strategies including vaccines against pulmonary MAC or MAB. A literature search was conducted using PubMed/MEDLINE and multiple search terms. The search was restricted to the English language and human studies. The database query resulted in a total of 197 publications. After the title and abstract review, 64 articles were included in this analysis. The guidelines by the American Thoracic Society (ATS), European Respiratory Society (ERS), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Infectious Diseases Society of America (IDSA) are widely applicable. The guidelines are based on expert opinion and there may be a need to broaden criteria to include those with underlying lung diseases who may not fulfill some of the criteria as 'probable cases' for better follow up and management. Some cases with only one culture-positive sputum sample or suggestive histology without a positive culture may benefit from new methods of confirming NTM infection. Amikacin liposomal inhalation suspension (ALIS), gallium containing compounds and immunotherapies will have potential in the management of pulmonary MAC and MAB. the prevalence of pulmonary NTM is increasing. The efforts to optimize diagnosis and treatment of pulmonary NTM are encouraging. There is still a need to develop new diagnostics and therapeutics.