-
Microbiology and Immunology 2004The species identification within Mycobacterium terrae complex has been known to be very difficult. In this study, the genomic diversity of M. terrae complex with...
The species identification within Mycobacterium terrae complex has been known to be very difficult. In this study, the genomic diversity of M. terrae complex with eighteen clinical isolates, which were initially identified as M. terrae complex by phenotypic method, was investigated, including that of three type strains (M. terrae, M. nonchromogenicum, and M. triviale ). 16S rRNA and 65-kDa heat shock protein (hsp 65) gene sequences of mycobacteria were determined and aligned with eleven other references for the comparison using similarity search against the GenBank and Ribosomal Database Project II (RDP) databases. 16S rRNA and hsp 65 genes of M. terrae complex showed genomic heterogeneity. Amongst the eighteen clinical isolates, nine were identified as M. nonchromogenicum, eight as M. terrae, one as M. mucogenicum with the molecular characteristic of rapid growth. M. nonchromogenicum could be subdivided into three subgroups, while M. terrae could be subdivided into two subgroups using a 5 bp criterion (>1% difference). Seven isolates in two subgroups of M. nonchromogenicum were Mycobacterium sp. strain MCRO 6, which was closely related to M. nonchromogenicum. The hsp 65 gene could not differentiate one M. nonchromogenicum from M. avium or one M. terrae from M. intracellulare. The nucleotide sequence analysis of 16S rRNA and hsp 65 genes was shown to be useful in identifying the M. terrae complex, but hsp 65 was less discriminating than 16S rRNA.
Topics: Bacterial Proteins; Base Sequence; Chaperonin 60; Chaperonins; DNA, Bacterial; DNA, Ribosomal; Databases, Factual; Genetic Variation; Genome, Bacterial; Molecular Sequence Data; Nontuberculous Mycobacteria; Phylogeny; RNA, Ribosomal, 16S
PubMed: 14978332
DOI: 10.1111/j.1348-0421.2004.tb03492.x -
International Journal of... Mar 2015Nontuberculous mycobacteria (NTM) are a diverse group of bacterial species that are distributed in the environment. Many of these environmental bacteria can cause... (Review)
Review
Nontuberculous mycobacteria (NTM) are a diverse group of bacterial species that are distributed in the environment. Many of these environmental bacteria can cause disease in humans. The identification of NTM in environmental sources is important for both clinical and epidemiological purposes. In this study, the distribution of NTM species from environmental and clinical samples in the Middle East was reviewed. In order to provide an overview of NTM, as well as recent epidemiological trends, all studies addressing NTM in the Middle East from 1984 to 2014 were reviewed. A total of 96 articles were found, in which 1751 NTM strains were isolated and 1084 of which were obtained from clinical samples, 619 from environmental samples and 48 were cited by case reports. Mycobacterium fortuitum was the most common rapid growing mycobacteria (RGM) isolated from both clinical (269 out of 447 RGM; 60.1%) and environmental (135 out of 289 RGM; 46.7%) samples. Mycobacterium avium complex (MAC) was the most common slow growing mycobacteria (SGM) isolated from clinical samples (140 out of 637 SGM; 21.9%). An increasing trend in NTM isolation from the Middle East was noted over the last 5years. This review demonstrates the increasing concern regarding NTM disease in the Middle East, emphasizing the need for regional collaboration and coordination in order to respond appropriately.
Topics: Epidemiological Monitoring; Humans; Middle East; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 26655192
DOI: 10.1016/j.ijmyco.2014.12.005 -
Frontiers in Public Health 2020Nontuberculous mycobacteria (NTM) that cause human disease can be isolated from household tap water. Easy-to-use physical methods to reduce NTM from this potential...
Nontuberculous mycobacteria (NTM) that cause human disease can be isolated from household tap water. Easy-to-use physical methods to reduce NTM from this potential source of exposure are needed. Filters and UV disinfection have been evaluated for their ability to reduce numbers of waterborne non-NTM organisms from drinking water, but their efficacy in reducing NTM counts are not well-established. Thus, five commercially available disinfection methods were evaluated for their potential as practical, efficient, and low-cost methods to reduce NTM from tap water. First, suspensions of tap water-adapted were passed through either a point-of-use, disposable, 7-day or 14-day Pall-Aquasafe filter. The 7-day filter prevented passage of in effluent water for 13 days, and the 14-day filter prevented the passage of for 25 days. Second, a granular activated carbon filter system failed to significantly reduce and numbers. Third, suspensions of tap water-adapted , and ("MycoCocktail") were passed through the "LifeStraw GO" hollow-fiber, two-stage membrane filtration system. LifeStraw GO prevented passage of the MycoCocktail suspension for the entire 68-day evaluation period. Finally, two different water bottle UV sterilization systems, "Mountop" and "SteriPEN," were evaluated for their capacity to reduce NTM numbers from tap water. Specifically, MycoCocktail suspensions were dispensed into Mountop and SteriPEN water bottles and UV treated as per the manufacturer instructions once daily for 7 days, followed by a once weekly treatment for up to 56 days. After 4 days of daily UV treatment, both systems achieved a >4 log reduction in MycoCocktail CFU. After the 56-day evaluation period, suspension and biofilm-associated CFU were measured, and a >4 log reduction in CFU was maintained in both systems. Taken together, physical disinfection methods significantly reduced NTM numbers from tap water and may be easy-to-use, accessible applications to reduce environmental NTM exposures from drinking water.
Topics: Disinfection; Humans; Mycobacterium abscessus; Mycobacterium avium; Nontuberculous Mycobacteria; Water
PubMed: 32596197
DOI: 10.3389/fpubh.2020.00190 -
Emerging Infectious Diseases Sep 2009Over the past several years, the prevalence of human disease caused by nontuberculous mycobacteria (NTM) has increased. Whether the increase in cases is real or whether... (Review)
Review
Over the past several years, the prevalence of human disease caused by nontuberculous mycobacteria (NTM) has increased. Whether the increase in cases is real or whether more cases are being recognized remains unclear. Despite a considerable increase in knowledge about NTM infections, they still represent a diagnostic and therapeutic challenge for several reasons: 1) pathogenic isolates may be indistinguishable from contaminant or saprophytic isolates; 2) timely and reliable identification of isolates may depend on proper communication between clinicians and laboratory staff; 3) lack of standardized susceptibility testing makes adoption of tailored therapies unrealistic; and 4) lack of treatment guidelines exposes patients to toxic drugs and disappointing outcomes. Laboratory research and multicenter controlled trials are needed to improve diagnosis and treatment of these infections.
Topics: Adult; Animals; Child, Preschool; Humans; Immunocompetence; Infant; Lymphadenitis; Mycobacterium; Mycobacterium Infections; Mycobacterium Infections, Nontuberculous; Mycobacterium marinum; Nontuberculous Mycobacteria; Prevalence; Skin Diseases, Bacterial; Soft Tissue Infections; Tuberculosis, Osteoarticular
PubMed: 19788801
DOI: 10.3201/eid1509.081259 -
Frontiers in Cellular and Infection... 2023The advent of metagenomics next-generation sequencing (mNGS) has garnered attention as a novel method for detecting pathogenic infections, including Non-Tuberculous...
INTRODUCTION
The advent of metagenomics next-generation sequencing (mNGS) has garnered attention as a novel method for detecting pathogenic infections, including Non-Tuberculous Mycobacterial (NTM) and tuberculosis (TB).However, the robustness and specificity of mNGS in NTM diagnostics have not been fully explored.
METHODS
In this retrospective study, we enrolled 27 patients with NTM genomic sequences via mNGS and conducted a comprehensive clinical evaluation.
RESULTS
Pulmonary NTM disease was the most commonly observed presentation, with a subset of patients also presenting with extrapulmonary NTM infections.mNGS analysis identified six distinct NTM species, primarily Mycobacteriumavium complex (MAC), followed by Mycobacterium intracellulare andMycobacterium abscessus. Conventional routine culture methods encountered challenges, resulting in negative results for all available 22 samples. Among the 10 patients who underwent quantitative polymerase chain reaction (qPCR) testing, five tested positive for NTM.
DISCUSSION
It is important to note that further species typing is necessary to determine the specific NTM type, as traditional pathogen detection methods serve as an initial step. In contrast, when supplemented with pathogen data, enables the identification of specific species, facilitating precise treatment decisions. In conclusion, mNGS demonstrates significant potential in aidingthe diagnosis of NTMdisease by rapidly detecting NTM pathogens and guiding treatment strategies. Its enhanced performance, faster turnaround time (TAT), and species identification capabilities make mNGS a promising tool for managing NTM infections.
Topics: Humans; Nontuberculous Mycobacteria; Metagenomics; Retrospective Studies; Metagenome; High-Throughput Nucleotide Sequencing; Mycobacterium abscessus
PubMed: 37719673
DOI: 10.3389/fcimb.2023.1253020 -
Respiratory Research Apr 2014Important paradigms of pulmonary disease with nontuberculous mycobacteria (NTM) are currently shifting based on an increasing attention within the field of cystic...
Important paradigms of pulmonary disease with nontuberculous mycobacteria (NTM) are currently shifting based on an increasing attention within the field of cystic fibrosis (CF). These shifts are likely to benefit the management of all patients with pulmonary NTM, regardless of underlying pathology. Currently several key areas are being revised: The first outbreak of human NTM transmission has been proven and new evidence of biofilm growth in vivo has been demonstrated. A better understanding of the clinical impact of NTM infection has led to increased diagnostic vigilance and new recommendations for lung transplantation are under way. While recent changes have reinvigorated the interest in NTM disease, the challenge remains, whether such advances can be successfully translated into improved management and care.
Topics: Anti-Bacterial Agents; Biofilms; Cystic Fibrosis; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 24725650
DOI: 10.1186/1465-9921-15-41 -
Journal of Applied Microbiology Aug 2009A majority of the Mycobacterium species, called the nontuberculous mycobacteria (NTM), are natural inhabitants of natural waters, engineered water systems, and soils. As... (Review)
Review
A majority of the Mycobacterium species, called the nontuberculous mycobacteria (NTM), are natural inhabitants of natural waters, engineered water systems, and soils. As a consequence of their ubiquitous distribution, humans are surrounded by these opportunistic pathogens. A cardinal feature of mycobacterial cells is the presence of a hydrophobic, lipid-rich outer membrane. The hydrophobicity of NTM is a major determinant of aerosolization, surface adherence, biofilm-formation, and disinfectant- and antibiotic resistance. The NTM are oligotrophs, able to grow at low carbon levels [>50 microg assimilable organic carbon (AOC) l(-1)], making them effective competitors in low nutrient, and disinfected environments (drinking water). Biofilm formation and oligotrophy lead to survival, persistence, and growth in drinking water distribution systems. In addition to their role as human and animal pathogens, the widespread distribution of NTM in the environment, coupled with their ability to degrade and metabolize a variety of complex hydrocarbons including pollutants, suggests that NTM may be agents of nutrient cycling.
Topics: Disinfection; Environmental Microbiology; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Water Supply
PubMed: 19228258
DOI: 10.1111/j.1365-2672.2009.04161.x -
Indian Journal of Medical Microbiology 2011The pathogenic potential of the rapidly growing mycobacteria (RGM) has started being recognized. This is due to more sensitive and specific techniques in the laboratory.... (Review)
Review
The pathogenic potential of the rapidly growing mycobacteria (RGM) has started being recognized. This is due to more sensitive and specific techniques in the laboratory. The RGM are generally defined as nontuberculous species of mycobacteria that show visible growth on agar media within 7 days. RGM are widely distributed in nature and have been isolated from natural water, tap water, and soil. Several biochemical tests, high performance liquid chromatography, and molecular techniques have been developed for rapid identification of these species. The American Thoracic Society and the Infectious Disease Society of America recommend that RGM should be identified to the species level using a recognized acceptable methodology such as polymerase chain reaction restriction enzyme analysis or biochemical testing and routine susceptibility testing of RGM should include amikacin, imipenem, doxycycline, the fluorinated quinolones, a sulphonamide or trimethoprim-sulphamethoxazole, cefoxitin, clarithromycin, linezolid, and tobramycin. The diseases caused by these organisms have varied manifestations. They have been responsible for a number of healthcare-associated outbreaks and pseudo-outbreaks. For recognition of outbreaks, it is important to be familiar with the causative organisms like RGM which are most frequently involved in healthcare-associated outbreaks and pseudo outbreaks. It is essential to intervene as soon as possible to interrupt this transmission. Large gaps still exist in our knowledge of RGM. Unquestionably more studies are required. Through this review, we wish to emphasize that reporting of RGM from clinical settings along with their sensitivity patterns is an absolute need of the hour.
Topics: Anti-Bacterial Agents; Bacteriological Techniques; Cross Infection; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 22120792
DOI: 10.4103/0255-0857.90157 -
International Journal of... Mar 2015Nontuberculous mycobacteria (NTM) are emergent pathogens whose importance in human health has been gaining relevance after being recognized as etiological agents of...
Nontuberculous mycobacteria (NTM) are emergent pathogens whose importance in human health has been gaining relevance after being recognized as etiological agents of opportunist infections in HIV patients. Currently, NTM are recognized as etiological agents of several respiratory and extra-respiratory infections of immune-competent individuals. The environmental nature of NTM together with the ability to assemble biofilms on different surfaces plays a key role on their pathogenesis. In the present work the ability of three fast-growing NTM (Mycobacterium smegmatis, Mycobacterium fortuitum and Mycobacterium chelonae) to persist within a model of human alveolar macrophages was evaluated. Most often human infections with NTM occur by contact with the environment. Biofilms can work as environmental reservoirs. For this reason, it was decided to evaluate the ability of NTM to assemble biofilms on different surfaces. Scanning electron microscopy was used to elucidate the biofilm structure. The ability to assemble biofilms was connected with the ability to spread on solid media known as sliding. Biofilm assembly and intracellular persistence seems to be ruled by different mechanisms.
Topics: Bacterial Adhesion; Biofilms; Cell Line; Humans; Macrophages, Alveolar; Microscopy, Electron, Scanning; Mycobacterium Infections, Nontuberculous; Mycobacterium chelonae; Mycobacterium fortuitum; Mycobacterium smegmatis; Nontuberculous Mycobacteria
PubMed: 26655196
DOI: 10.1016/j.ijmyco.2014.11.065 -
BioMed Research International 2015
Topics: Anti-Bacterial Agents; Clinical Trials as Topic; Genetic Predisposition to Disease; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 26161405
DOI: 10.1155/2015/523697