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Expert Review of Respiratory Medicine Sep 2019: The incidence and prevalence rates of nontuberculous mycobacterial (NTM) pulmonary disease have been continuously increasing worldwide. However, the rate of successful... (Review)
Review
: The incidence and prevalence rates of nontuberculous mycobacterial (NTM) pulmonary disease have been continuously increasing worldwide. However, the rate of successful treatment of this disease greatly needs improving, particularly when intrinsic (natural) drug resistance and acquired drug resistance in NTM pulmonary disease are associated with poor outcomes for patients. : This review covers the major pathogens that cause NTM pulmonary disease caused by complex, , and ; the key drugs and recommended regimens used in the treatment of NTM pulmonary disease; the factors that contribute to resistance to the key drugs, including genetic factors and monotherapy; and the treatment strategies, including revised antibiotic regimens and surgery, that can be used to treat drug-resistant NTM pulmonary disease. : To avoid and overcome drug resistance in NTM pulmonary disease, the appropriate guideline-based treatments are essential, and clinical studies to evaluate new or repurposed drugs are urgently needed.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Humans; Lung; Lung Diseases; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 31256694
DOI: 10.1080/17476348.2019.1638765 -
Experimental and Clinical... Oct 2021Data are limited regarding the clinical significance of nontuberculous mycobacteria pulmonary infections among lung transplant recipients. We investigated the incidence...
OBJECTIVES
Data are limited regarding the clinical significance of nontuberculous mycobacteria pulmonary infections among lung transplant recipients. We investigated the incidence and characteristics of pulmonary nontuberculous mycobacteria infection in ourlung transplant patient population.
MATERIALS AND METHODS
We obtaineddata of the patients who underwent lung transplant in our center from January 1997 to March 2019.
RESULTS
Of 690 patients, nontuberculous mycobacteria were identified in 58 patients (8.4%) over a median follow-up of 3 years. Types of species were as follows: Mycobacterium simiae (n = 24), avium complex (n = 12), abscessus (n = 9), fortuitum (n = 6), chelonae (n = 2), szulgai (n = 1), kansasii (n = 1), lentiflavum (n = 1), and undefined mycobacteria (n = 2). When we compared infections in the early versus late period posttransplant (before and after 6 months), infections with Mycobacterium simiae (16 vs 8 incidents) and Mycobacterium fortuitum (5 vs 1 incident) were more often observed within the early period, whereas most Mycobacterium abscessus (7 vs 1 incident) and Mycobacterium avium complex (9 vs 3 incidents) were observed in the later period. The median forced expiratory volume in 1 second overtime did not differ significantly between patients with and without nontuberculous mycobacteria infection (P = .29). Nontuberculous mycobacteria acquisition was significantly associated with decreased survival (relative risk of 2.41, 95% CI, 1.70-3.43; P ⟨ .001).
CONCLUSIONS
The nontuberculous mycobacteria species isolated varied according to the time elapsed since transplant. Among lung transplant recipients, nontuberculous mycobacteria infection was associated with increased mortality but not with lung dysfunction.
Topics: Humans; Lung; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Opportunistic Infections; Transplant Recipients; Treatment Outcome
PubMed: 34641777
DOI: 10.6002/ect.2021.0177 -
Infection, Genetics and Evolution :... Aug 2019Seventy years have passed since Ernest H. Runyon presented a phenotypic classification approach for nontuberculous mycobacteria (NTM), primarily as a starting point in... (Review)
Review
Seventy years have passed since Ernest H. Runyon presented a phenotypic classification approach for nontuberculous mycobacteria (NTM), primarily as a starting point in trying to understand their clinical relevance. From numerical taxonomy (biochemical testing) to 16S rRNA gene sequencing to whole genome sequencing (WGS), our understanding of NTM has also evolved. Novel species are described at a rapid pace, while taxonomical relationships are re-defined in large part due to the accessibility of WGS. The evolutionary course of clonal complexes within species is better known for some NTM and less for others. In contrast with M. tuberculosis, much is left to learn about NTM as a whole.
Topics: DNA, Bacterial; Evolution, Molecular; Genomics; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Phylogeny; RNA, Ribosomal, 16S; Whole Genome Sequencing
PubMed: 30654178
DOI: 10.1016/j.meegid.2019.01.017 -
International Journal of... 2019The nontuberculous mycobacteria (NTM) have recently emerged as important bacterial pathogens of both animals and humans. Of particular, concern is the high level of... (Review)
Review
The nontuberculous mycobacteria (NTM) have recently emerged as important bacterial pathogens of both animals and humans. Of particular, concern is the high level of antimicrobial resistance (AMR) displayed by these organisms, which complicates treatment and potential successful outcomes. This review, therefore, wishes to examine novel compounds and approaches to combatting AMR in the NTMs, specifically examining antimycobacterial (NTM) compounds from plants and venoms, as well as examining synergistic and combination effects with other antimicrobials. Novel and modified drugs including new inhaled drugs are examined, as well as the repurposing of existing drugs for antimycobacterial activity. Many of these novel interventions are at various stages of development, from initial concept through to licensed intervention. The challenge remains to translate these interventions from in vitro laboratory models to effective in vivo interactions. When these are realized, then we will have the opportunity of overcoming NTM AMR, to the benefit of medicine, society, and humanity.
Topics: Antitubercular Agents; Drug Discovery; Drug Repositioning; Drug Resistance, Bacterial; Drug Synergism; Drug Therapy, Combination; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 30860173
DOI: 10.4103/ijmy.ijmy_153_18 -
International Journal of... Jun 2015Pulmonary infections with nontuberculous mycobacteria (NTM) are recognized as a problem in immunodeficient individuals and are increasingly common in older people with... (Review)
Review
Pulmonary infections with nontuberculous mycobacteria (NTM) are recognized as a problem in immunodeficient individuals and are increasingly common in older people with no known immune defects. NTM are found in soil and water, but factors influencing transmission from the environment to humans are mostly unknown. Studies of the epidemiology of NTM disease have matched some clinical isolates of NTM with isolates from the patient's local environment. Definitive matching requires strain level differentiation based on molecular analyses, including partial sequencing, PCR-restriction fragment length polymorphism (RFLP) analysis, random amplified polymorphic DNA (RAPD) PCR, repetitive element (rep-) PCR and pulsed field gel electrophoresis (PFGE) of large restriction fragments. These approaches have identified hospital and residential showers and faucets, hot-tubs and garden soil as sources of transmissible pathogenic NTM. However, gaps exist in the literature, with many clinical isolates remaining unidentified within environments that have been tested, and few studies investigating NTM transmission in developing countries. To understand the environmental reservoirs and transmission routes of pathogenic NTM, different environments, countries and climates must be investigated.
Topics: Environmental Microbiology; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 26972876
DOI: 10.1016/j.ijmyco.2015.03.002 -
Respiration; International Review of... 2022Nontuberculous mycobacteria (NTM) are increasingly identified in industrialized countries, and their role as pathogens is more frequently recognized. The relative...
BACKGROUND
Nontuberculous mycobacteria (NTM) are increasingly identified in industrialized countries, and their role as pathogens is more frequently recognized. The relative prevalence of NTM strains shows an important geographical variability. Thus, establishing the local relative prevalence of NTM strains is relevant and useful for clinicians.
METHODS
Retrospective analysis (2015-2020) of a comprehensive database was conducted including all results of cultures for mycobacteria in a University Hospital (Geneva, Switzerland), covering a population of approximately 500,000 inhabitants. All NTM culture-positive patients were included in the analyses. Patients' characteristics, NTM strains, and time to culture positivity were reported.
RESULTS
Among 38,065 samples analyzed during the study period, 411 were culture-positive for NTM, representing 236 strains, and 231 episodes of care which occurred in 222 patients. Patients in whom NTM were identified were predominantly female (55%), with a median age of 62 years, and a low BMI (median: 22.6 kg/m2). The Mycobacterium avium complex (MAC) was the most frequently identified group (37% of strains) followed by Mycobacterium gordonae (25%) and Mycobacterium xenopi (12%) among the slowly growing mycobacteria (SGM), while the Mycobacterium chelonae/abscessus group (11%) were the most frequently identified rapidly growing mycobacteria (RGM). Only 19% of all patients were treated, mostly for pulmonary infections: the MAC was the most frequently treated NTM (n = 19, 43% of cases in patients treated) followed by RGM (n = 15, 34%) and M. xenopi (n = 6, 14%). Among those treated, 23% were immunosuppressed, 12% had pulmonary comorbidities, and 5% systemic comorbidities. Cultures became positive after a median of 41 days (IQR: 23; 68) for SGM and 28 days (14; 35) for RGM.
CONCLUSIONS
In Western Switzerland, M. avium and M. gordonae were the most prevalent NTM identified. Positive cultures for NTM led to a specific treatment in 19% of subjects. Patients with a positive culture for NTM were mostly female, with a median age of 62 years, a low BMI, and a low prevalence of immunosuppression or associated severe comorbidities.
Topics: Female; Humans; Male; Middle Aged; Mycobacterium Infections, Nontuberculous; Mycobacterium avium Complex; Mycobacterium xenopi; Nontuberculous Mycobacteria; Retrospective Studies
PubMed: 34875659
DOI: 10.1159/000520033 -
Journal of the Formosan Medical... Jun 2020Great progress has recently been made in methodologies for identifying nontuberculous mycobacteria (NTM). Recommendations for drug susceptibility testing (DST) of NTM... (Review)
Review
Great progress has recently been made in methodologies for identifying nontuberculous mycobacteria (NTM). Recommendations for drug susceptibility testing (DST) of NTM have been expanded and updated by the Clinical and Laboratory Standards Institute and are crucial in the management of NTM infections. This article summarizes the clinically relevant molecular methods used to discriminate NTM species and updates the information on DST. Furthermore, recent progress on new antimicrobials against NTM infections is reviewed.
Topics: Anti-Bacterial Agents; Humans; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Mycobacterium tuberculosis; Nontuberculous Mycobacteria
PubMed: 32423573
DOI: 10.1016/j.jfma.2020.05.002 -
The Journal of Infection Mar 2016Pulmonary non-tuberculous mycobacterial infection (NTM) is a challenging and increasingly prevalent infection. Antimicrobial resistance is common and may be associated...
OBJECTIVES
Pulmonary non-tuberculous mycobacterial infection (NTM) is a challenging and increasingly prevalent infection. Antimicrobial resistance is common and may be associated with poor outcomes. This retrospective study aimed to report longitudinal trends in mycobacterial isolation and NTM drug susceptibility.
METHODS
Mycobacterial culture and drug sensitivity testing results were obtained over a 13 year period. Drug sensitivity testing was performed by broth macrodilution for slow-growing mycobacteria and disc diffusion for rapidly growing mycobacteria.
RESULTS
Culture results were obtained from 109,311 samples (31,758 subjects) of which 5960 samples (1209 subjects) isolated NTM over 13 years. Drug susceptibility results were obtained for 2637 NTM isolates (898 subjects). NTM isolation increased over time, driven by the Mycobacterium avium complex and Mycobacterium abscessus. Amongst most species, resistance to the key agents clarithromycin and amikacin was rare. The highest rate of resistance was found in M. abscessus and Mycobacterium simiae. Most M. abscessus isolates were sensitive to macrolides, aminoglycosides and tigecycline; M. simiae isolates were only consistently sensitive to clofazimine, amikacin and cycloserine.
CONCLUSIONS
NTM isolation is increasingly common in our centre. Reassuringly, resistance to clarithromycin and amikacin is rare in most species. Tigecycline, cycloserine and clofazimine may be useful in the treatment of the most resistant species, M. abscessus and M. simiae.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Drug Resistance, Bacterial; Female; Humans; Infant; Infant, Newborn; Male; Microbial Sensitivity Tests; Middle Aged; Mycobacterium Infections; Nontuberculous Mycobacteria; Pneumonia, Bacterial; Retrospective Studies; Young Adult
PubMed: 26723913
DOI: 10.1016/j.jinf.2015.12.007 -
BMC Infectious Diseases Mar 2024Nontuberculous mycobacteria (NTM) are environmental bacteria which may cause chronic lung disease. The prevalence of NTM pulmonary infection and disease has been...
BACKGROUND
Nontuberculous mycobacteria (NTM) are environmental bacteria which may cause chronic lung disease. The prevalence of NTM pulmonary infection and disease has been increasing in the United States and globally. The predominant clinically relevant species of NTM in the United States are Mycobacterium avium complex (MAC) species and Mycobacterium abscessus. With the development of rapid species identification methods for NTM (e.g. PCR probes), more testing for NTM is being conducted through commercial labs, such as Laboratory Corporation of America (Labcorp), which provides deidentified real-time testing data to the Centers for Disease Control (CDC) pursuant to a data sharing agreement. Because NTM lung infections are not reportable in most states, other data sources are key to understanding NTM testing patterns, positivity rates, and species distributions to track infection trends and identify clinical care needs.
METHODS
We obtained national Labcorp data for the period January 2019 through mid-April 2022. We subset the data to only respiratory samples sent for Acid Fast Bacilli (AFB) cultures. NTM positive results were defined as those which identified an NTM species and are not Mycobacterium tuberculosis, Mycobacterium bovis, or Mycobacterium gordonae.
RESULTS
Overall, 112,528 respiratory samples were sent for AFB testing during the study period; 26.3% were from the Southeast U.S., identified as HSS Region IV in the Labcorp dataset, and 23.0% were from the Pacific and South Pacific region (Region IX). The culture positive prevalence ranged from 20.2% in the Southeast to 9.2% in the East North Central region (Region V). In the Southeast US, M. abscessus prevalence was 4.0%. For MAC, the highest prevalence was observed in the Mountain region (Region VII) (13.5%) and the lowest proportion was in the East South Central region (7.3%, Region III). Among positive tests, the proportion which was MAC varied from 61.8% to 88.9% and was highest in the Northeast U.S. The proportion of positive samples which were M. abscessus ranged from 3.8% to 19.7% and was highest in the Southeast.
CONCLUSIONS
The Southeastern region of the U.S. has the highest rate of culture positivity in Labcorp tests for total NTM and, of all positive tests, the highest proportion of M. abscessus. These estimates may underrepresent the true number of M. abscessus infections because M. absesscus-specific probes are not commercially available and not all NTM testing in the United States is done by Labcorp. Analysis of real-time testing data from commercial laboratories may provide insights into risk factors for NTM culture positivity in 'hotspot' areas.
Topics: United States; Humans; Nontuberculous Mycobacteria; Mycobacterium avium Complex; Mycobacterium abscessus; Laboratories; Mycobacterium bovis; Opportunistic Infections
PubMed: 38448840
DOI: 10.1186/s12879-024-09059-9 -
Respiratory Investigation May 2020
Topics: Humans; Lung Diseases; Mycobacterium Infections, Nontuberculous; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Tuberculosis, Pulmonary
PubMed: 32179021
DOI: 10.1016/j.resinv.2020.02.001