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Microbiology Spectrum Jun 2024Four species of non-tuberculous mycobacteria (NTM) rated as biosafety level 1 or 2 (BSL-1/BSL-2) organisms and showing higher genomic similarity with () than previous...
Four species of non-tuberculous mycobacteria (NTM) rated as biosafety level 1 or 2 (BSL-1/BSL-2) organisms and showing higher genomic similarity with () than previous comparator species and were subjected to genomic and phenotypic characterization. These species named , , and might represent "missing links" between low-virulent mycobacterial opportunists and the highly virulent obligate pathogen . We confirmed that is the closest NTM species to currently known and found that it has an optimal growth temperature of 32°C-35°C and not 37°C. showed resistance to rifampicin, isoniazid, and ethambutol, whereas and showed resistance to isoniazid and ethambutol. was sensitive to all three first-line TB drugs, and all four species were sensitive to bedaquiline, a third-generation anti-TB drug. Our results suggest these four NTM may be useful models for the identification and study of new anti-TB molecules, facilitated by their culture under non-BSL-3 conditions as compared to was the most virulent of the four species in cellular and mouse infection models. also multiplied in THP-1 cells at 35°C but was growth impaired at 37°C. Genomic comparisons showed that the locus, essential for the secretion of ESX-1 proteins in , was present only in , which was able to secrete ESAT-6 and CFP-10, whereas secretion of these antigens varied in the other species, making the four species interesting examples for studying ESX-1 secretion mechanisms.IMPORTANCEIn this work, we investigated recently identified opportunistic mycobacterial pathogens that are genomically more closely related to () than previously used comparator species and . We confirmed that is the currently closest known species to the tubercle bacilli, represented by and strains. Surprisingly, the reference strain of (DSM 45176), which was purchased as a biosafety level 1 (BSL-1)-rated organism, was the most virulent of the four species in the tested cellular and mouse infection models, suggesting that a BSL-2 rating might be more appropriate for this strain than the current BSL-1 rating. Our work establishes the four NTM species as interesting study models to obtain new insights into the evolutionary mechanisms and phenotypic particularities of mycobacterial pathogens that likely have also impacted the evolution of the key pathogen .
Topics: Mycobacterium tuberculosis; Antitubercular Agents; Nontuberculous Mycobacteria; Humans; Genome, Bacterial; Genomics; Phenotype; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Phylogeny; Animals; Tuberculosis; Drug Resistance, Bacterial; Mice
PubMed: 38700329
DOI: 10.1128/spectrum.04126-23 -
BMC Microbiology Apr 2018Mycobacteriosis caused by non-tuberculous mycobacteria (NTM), is among the most chronic diseases of aquatic animals. In addition, fish mycobacteriosis has substantial...
BACKGROUND
Mycobacteriosis caused by non-tuberculous mycobacteria (NTM), is among the most chronic diseases of aquatic animals. In addition, fish mycobacteriosis has substantial economic consequences especially in the aquaculture and fisheries industry as infections may significantly decrease production and trade. Some fish NTM pathogens are highly virulent and zoonotic; as such, infection of aquaria with these pathogens is a public health concern. In this study, we report isolation of nine different NTM species from sixteen aquatic animals including different fish species, frogs and a crocodile. Given the clinical significance of Mycobacterium marinum and its close relation to Mycobacterium tuberculosis, as well as the significance of ESAT 6 and CFP-10 secretion in mycobacterial virulence, we analysed the esxA and esxB nucleotide sequences of M. marinum isolates identified in this study as well as other mycobacteria in the public databases.
RESULTS
Mycobacterium shimoidei, Mycobacterium marinum, Mycobacterium chelonae, Mycobacterium septicum /M. peregrinum and Mycobacterium porcinum were isolated from gold fish, Guppy, exotic fish species in South Africa, koi and undefined fish, Knysna seahorse, as well Natal ghost frogs respectively, presenting tuberculosis like granuloma. Other NTM species were isolated from the studied aquatic animals without any visible lesions, and these include Mycobacterium sp. N845 T, Mycobacterium fortuitum, a member of the Mycobacterium avium complex, and Mycobacterium szulgai. Phylogenetic analysis of mycobacteria, based on esxA and esxB genes, separated slow growing from rapidly growing mycobacteria as well as pathogenic from non-pathogenic mycobacteria in some cases.
CONCLUSIONS
Isolation of the different NTM species from samples presenting granuloma suggests the significance of these NTM species in causing mycobacteriosis in these aquatic animals. The study also revealed the potential of esxA and esxB sequences as markers for phylogenetic classification of mycobacteria. Observations regarding use of esxA and esxB sequences for prediction of potential pathogenicity of mycobacteria warrants further investigation of these two genes in a study employing NTM species with well-defined pathogenicity.
Topics: Alligators and Crocodiles; Animals; Antigens, Bacterial; Anura; Bacterial Proteins; Base Sequence; Fish Diseases; Fishes; Genes, Bacterial; Genetic Markers; Mycobacterium Infections, Nontuberculous; Mycobacterium chelonae; Mycobacterium marinum; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Phylogeny; Poecilia; RNA, Ribosomal, 16S; South Africa; Virulence
PubMed: 29653505
DOI: 10.1186/s12866-018-1177-9 -
International Journal of... 2021Nontuberculous mycobacteria (NTM) have been recognized as a diverse group of organisms that are ubiquitous in environmental sources. In most regions of the world, NTM...
OBJECTIVE
Nontuberculous mycobacteria (NTM) have been recognized as a diverse group of organisms that are ubiquitous in environmental sources. In most regions of the world, NTM are not reportable as a public health disease, so epidemiological data are not easily available. However, data in published studies note increasing trends at the rate of NTM isolation from different geographic regions of the world. Increasing NTM isolation may have important public health implications. The aim of our study is the investigation of NTM from water resources and networks in Düzce, Turkey.
METHODS
NTM are common in water resources and water networks. They can cause waterborne infections in humans. A total of 120 water samples measured of chlorine and pH levels were decontaminated and filtered. Then, the filters were placed in the culturing media.
STATISTICAL ANALYSIS USED
Chi-square and t-test were used for the statistical analysis.
RESULTS
NTM were detected in 20 (16.6%) samples. Nine of them (45%) were Mycobacterium fortuitum, three (15%) were Mycobacterium gordonae, three (15%) were Mycobacterium szulgai, two (10%) were Mycobacterium lentiflavum, two (10%) were Mycobacterium chelonae, and one (5%) was Mycobacterium peregrinum.
CONCLUSIONS
These environmental bacteria can cause serious illnesses in both immunocompetent and especially immunocompromised individuals. For the correct treatment of these patients, it is important to determine NTM in clinical samples. Surveillance is necessary to know the source of NTM infection, to identify and type the strains, and to establish effective control measures such as disinfection, maintenance, and modernization of water systems.
Topics: Drinking Water; Humans; Mycobacteriaceae; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 34558473
DOI: 10.4103/ijmy.ijmy_82_21 -
Expert Opinion on Pharmacotherapy Jun 2020Non-tuberculous Mycobacteria (NTM) are a group of organisms whose importance in medicine seems to be increasing in recent times. The increasing number of patients... (Review)
Review
INTRODUCTION
Non-tuberculous Mycobacteria (NTM) are a group of organisms whose importance in medicine seems to be increasing in recent times. The increasing number of patients susceptible to these diseases make it necessary to expand our knowledge of therapeutic options and to explore future possibilities for the development of a therapeutic arsenal.
AREAS COVERED
In this review, the authors provide a brief introduction about the present importance of NTM and describe the present recommendations of the available guidelines for their treatment. They include a description of the future options for the management of these patients, especially focusing on new antibiotics. The authors also look at possibilities for future therapeutic options, such as antibiofilm strategies.
EXPERT OPINION
No actual changes have been made to the current recommendations for the management of most NTM infections (except perhaps the availability of nebulized amikacin). However, it is also true that we have increased the number of available antibiotic treatment options with good in vitro activity against NTM. The use of these drugs in selected cases could increase the therapeutic possibilities. However, some problems are still present, such as the knowledge of the actual meaning of a NTM isolate, and will probably be a key part of future research.
Topics: Amikacin; Anti-Bacterial Agents; Humans; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Practice Guidelines as Topic
PubMed: 32200657
DOI: 10.1080/14656566.2020.1740205 -
American Journal of Respiratory and... May 2022Healthcare-associated transmission of nontuberculous mycobacteria (NTM) among people with cystic fibrosis (pwCF) has been investigated at CF centers worldwide, with...
Healthcare-associated transmission of nontuberculous mycobacteria (NTM) among people with cystic fibrosis (pwCF) has been investigated at CF centers worldwide, with conflicting conclusions. We investigated transmission at the Colorado Adult CF Program. To systematically investigate healthcare-associated transmission and/or acquisition of NTM to determine similarity among respiratory and environmental isolates, and to compare home residence watershed mapping among pwCF having genetically similar NTM isolates. Whole-genome sequencing of NTM isolates from 80 pwCF was conducted to identify genetically similar isolate clusters (⩽30 SNP differences). Epidemiology, comparison of respiratory and environmental isolates, and home residence watershed mapping were analyzed. Whole-genome sequencing analysis revealed 11 clusters of NTM [6 subspecies (ssp.) , 1 ssp. , 2 , and 2 ] among pwCF. Epidemiologic investigation demonstrated opportunities for healthcare-associated transmission in two and two clusters. Respiratory and healthcare environmental isolate comparisons revealed no genetic similarity. Individuals comprising one cluster, with no plausible healthcare-associated transmission, resided in the same watershed. This study suggests healthcare-associated transmission of is rare and includes a report of potential healthcare-associated transmission of among pwCF. One cluster possibly had common acquisition arising from residing in the same watershed. The presence of genetically similar isolates is insufficient to demonstrate healthcare-associated NTM transmission. Standardizing epidemiologic investigation, combined with environmental sampling and watershed analysis, will improve understanding of the frequency and nature of healthcare-associated NTM transmission among pwCF.
Topics: Adult; Colorado; Cystic Fibrosis; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Nontuberculous Mycobacteria
PubMed: 35085056
DOI: 10.1164/rccm.202108-1911OC -
Journal of Clinical Microbiology Jan 2020infection and nontuberculous mycobacteria (NTM) infections exhibit similar clinical symptoms; however, the therapies for these two types of infections are different....
infection and nontuberculous mycobacteria (NTM) infections exhibit similar clinical symptoms; however, the therapies for these two types of infections are different. Therefore, the rapid and accurate identification of and NTM species is very important for the control of tuberculosis and NTM infections. In the present study, a Cas12a/guide RNA (gRNA)-based platform was developed to identify and most NTM species. By designing species-specific gRNA probes targeting the sequence, a Cas12a/gRNA-based platform successfully identified and six major NTM species (, , , , , and ) without cross-reactivity. In a blind assessment, a total of 72 out of 73 clinical isolates were correctly identified, which is consistent with previous sequencing results. These results suggest that the Cas12a/gRNA-based platform is a promising tool for the rapid, accurate, and cost-effective identification of both and NTM species.
Topics: Bacterial Proteins; CRISPR-Associated Proteins; CRISPR-Cas Systems; Endodeoxyribonucleases; Humans; Mycobacterium; Mycobacterium Infections, Nontuberculous; Mycobacterium avium Complex; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; RNA Probes; RNA, Guide, CRISPR-Cas Systems; RNA, Ribosomal, 16S; Sensitivity and Specificity; Tuberculosis
PubMed: 31723010
DOI: 10.1128/JCM.01368-19 -
Archivos de Bronconeumologia Oct 2017Non-tuberculous mycobacteria (NTM) isolates are becoming more common. The main objective of our study was to establish the number and diversity of NTM species in our...
INTRODUCTION AND OBJECTIVE
Non-tuberculous mycobacteria (NTM) isolates are becoming more common. The main objective of our study was to establish the number and diversity of NTM species in our region and their distribution according to the source sample, age and gender of the patients, and to analyse clinically significant isolates.
METHODOLOGY
Prospective study of all NTM isolated in Asturias from 2005 to 2012. Samples were processed following internationally accepted guidelines. Statistical analysis was based on Fisher's exact test for 2×2 contingency tables.
RESULTS
A total of 3,284 mycobacteria were isolated: 1,499 Mycobacterium tuberculosis complex (MTB) and 1,785 NTM.During the study, NTM isolation rates increased while MTB isolation decreased. NTM were more frequent in men (P<.001). M.gordonae was the most frequently isolated species but did not cause disease in any case. NTM isolates from 212 patients were associated with clinically significant disease (17.1%). M.kansasii and M.avium were most commonly associated with disease. The number of M.kansasii isolates from men was statistically significant (P<.01).
CONCLUSIONS
In our study, NTM isolates increased by 35%, compared with a 21% decline in cases of MTB. Both isolation of NTM and clinically significant cases were more common in men. Only 17.1% of NTM isolates were associated with disease, most commonly M.avium complex and M.kansasii.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Typing Techniques; Child; Child, Preschool; Communicable Diseases, Emerging; Feces; Female; Hospitals, Public; Humans; Infant; Lymph Nodes; Male; Middle Aged; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Prospective Studies; Respiratory System; Skin; Spain; Species Specificity; Urine; Young Adult
PubMed: 28433210
DOI: 10.1016/j.arbres.2017.02.014 -
The Cochrane Database of Systematic... Jun 2020Nontuberculous mycobacteria are mycobacteria, other than those in the Mycobacterium tuberculosis complex, and are commonly found in the environment. Nontuberculous...
BACKGROUND
Nontuberculous mycobacteria are mycobacteria, other than those in the Mycobacterium tuberculosis complex, and are commonly found in the environment. Nontuberculous mycobacteria species (most commonly Mycobacterium avium complex and Mycobacterium abscessus) are isolated from the respiratory tract of approximately 5% to 40% of individuals with cystic fibrosis; they can cause lung disease in people with cystic fibrosis leading to more a rapid decline in lung function and even death in certain circumstances. Although there are guidelines for the antimicrobial treatment of nontuberculous mycobacteria lung disease, these recommendations are not specific for people with cystic fibrosis and it is not clear which antibiotic regimen may be the most effective in the treatment of these individuals. This is an update of a previous review.
OBJECTIVES
The objective of our review was to compare antibiotic treatment to no antibiotic treatment, or to compare different combinations of antibiotic treatment, for nontuberculous mycobacteria lung infections in people with cystic fibrosis. The primary objective was to assess the effect of treatment on lung function and pulmonary exacerbations and to quantify adverse events. The secondary objectives were to assess treatment effects on the amount of bacteria in the sputum, quality of life, mortality, nutritional parameters, hospitalizations and use of oral antibiotics.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and hand searching of journals and conference abstract books. Date of last search: 24 February 2020. We also searched a register of ongoing trials and the reference lists of relevant articles and reviews. Date of last search: 21 March 2019.
SELECTION CRITERIA
Any randomized controlled trials comparing nontuberculous mycobacteria antibiotics to no antibiotic treatment, as well as one nontuberculous mycobacteria antibiotic regimen compared to another nontuberculous mycobacteria antibiotic regimen, in individuals with cystic fibrosis. DATA COLLECTION AND ANALYSIS: Data were not collected because in the one trial identified by the search, data specific to individuals with cystic fibrosis could not be obtained from the pharmaceutical company.
MAIN RESULTS
One completed trial was identified by the searches, but data specific to individuals with cystic fibrosis could not be obtained from the pharmaceutical company.
AUTHORS' CONCLUSIONS
This review did not find any evidence for the effectiveness of different antimicrobial treatment for nontuberculous mycobacteria lung disease in people with cystic fibrosis. Until such evidence becomes available, it is reasonable for clinicians to follow published clinical practice guidelines for the diagnosis and treatment of nodular or bronchiectatic pulmonary disease due to Mycobacterium avium complex or Mycobacterium abscessus in patients with cystic fibrosis.
Topics: Anti-Bacterial Agents; Cystic Fibrosis; Drug Therapy, Combination; Humans; Lung Diseases; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Mycobacterium avium Complex; Nontuberculous Mycobacteria
PubMed: 32521055
DOI: 10.1002/14651858.CD010004.pub5 -
Microbiology (Reading, England) May 2020is so far the most thermophilic among mycobacteria as it grows optimally at 50 °C and up to 65 °C in a glycerol-based medium, as verified in this study. Since...
is so far the most thermophilic among mycobacteria as it grows optimally at 50 °C and up to 65 °C in a glycerol-based medium, as verified in this study. Since this and other nontuberculous mycobacteria (NTM) thrive in diverse natural and artificial environments, from where they may access and infect humans, we deemed essential to probe resistance to heat, a strategy routinely used to control microbial growth in water-supply systems, as well as in the food and drink industries. In addition to possibly being a threat in its own right in rare occasions, is also a good surrogate for studying other NTM species more often associated with opportunistic infection, namely and as well as their strictly pathogenic counterparts and . In this regard, this thermophilic species is likely to be useful as a source of stable proteins that may provide more detailed structures of potential drug targets. Here, we investigate growth at near-pasteurization temperatures and at different pHs and also characterize its thermostable glucosyl-3-phosphoglycerate synthase (GpgS), an enzyme considered essential for growth and associated with both nitrogen starvation and thermal stress in different NTM species.
Topics: Bacterial Proteins; DNA, Bacterial; Glucosyltransferases; Hydrogen-Ion Concentration; Mycobacteriaceae; Nontuberculous Mycobacteria; Pasteurization; Temperature
PubMed: 32100712
DOI: 10.1099/mic.0.000898 -
Emerging Infectious Diseases Jul 2017Mycobacterium gordonae is often regarded as a weak pathogen that only occasionally causes overt disease. We report a case of M. gordonae infection in the facial skin,...
Mycobacterium gordonae is often regarded as a weak pathogen that only occasionally causes overt disease. We report a case of M. gordonae infection in the facial skin, nasal mucosa, and paranasal sinus in an immunocompetent patient and review previous cases. The T-SPOT.TB test might be useful in diagnosing such cases.
Topics: Anti-Bacterial Agents; Biopsy; China; Epistaxis; Female; Humans; Middle Aged; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Tomography, X-Ray Computed; Tuberculin Test; Ulcer
PubMed: 28628445
DOI: 10.3201/eid2307.162033