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PloS One 2019Mycobacterium canettii is a smooth bacillus related to the Mycobacterium tuberculosis complex. It causes lymph nodes and pulmonary tuberculosis in patients living in...
Mycobacterium canettii is a smooth bacillus related to the Mycobacterium tuberculosis complex. It causes lymph nodes and pulmonary tuberculosis in patients living in countries of the Horn of Africa, including Djibouti. The environmental reservoirs of M. canettii are still unknown. We aimed to further decrypt these potential reservoirs by using an original approach of High-Throughput Carbon and Azote Substrate Profiling. The Biolog Phenotype profiling was performed on six clinical strains of M. canettii and one M. tuberculosis strain was used as a positive control. The experiments were duplicated and authenticated by negative controls. While M. tuberculosis metabolized 22/190 (11%) carbon substrates and 3/95 (3%) nitrogen substrates, 17/190 (8.9%) carbon substrates and three nitrogen substrates were metabolized by the six M. canettii strains forming the so-called corebiologome. A total at 16 carbon substrates and three nitrogen substrates were metabolized in common by M. tuberculosis and the six M. canettii strains. Moreover, at least one M. canettii strain metabolized 36/190 (19%) carbon substrates and 3/95 (3%) nitrogen substrates for a total of 39/285 (13%) substrates. Classifying these carbon and nitrogen substrates into ten potential environmental sources (plants, fruits and vegetables, bacteria, algae, fungi, nematodes, mollusks, mammals, insects and inanimate environment) significantly associated carbon and nitrogen substrates metabolized by at least one M. canettii strain with plants (p = 0.006). These results suggest that some plants endemic in the Horn of Africa may serve as ecological niches for M. canettii. Further ethnobotanical studies will indicate plant usages by local populations, then guiding field microbiological investigations in order to prove the definite environmental reservoirs of this opportunistic tuberculous pathogen.
Topics: Africa, Eastern; Animals; Bacterial Typing Techniques; Disease Reservoirs; Djibouti; Environmental Microbiology; High-Throughput Screening Assays; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Phenotype; Plants; Tuberculosis; Tuberculosis, Lymph Node; Tuberculosis, Pulmonary
PubMed: 31479485
DOI: 10.1371/journal.pone.0222078 -
International Journal of... Sep 2016Nontuberculous mycobacteria (NTM) infection associated with pulmonary and extrapulmonary disease has been increasing globally. Despite an increase in incidence rate of...
OBJECTIVE/BACKGROUND
Nontuberculous mycobacteria (NTM) infection associated with pulmonary and extrapulmonary disease has been increasing globally. Despite an increase in incidence rate of NTM infection, its prevalence, species diversity, and circulation pattern in India is largely unknown. This study sought to investigate the overall burden and diversity of NTM among both pulmonary and extrapulmonary clinical isolates from a Northern Indian population.
METHODS
The study was conducted in the Department of Microbiology, from January 2013 to December 2015. A total of 4620 clinical samples were collected from patients suspected to have pulmonary and extrapulmonary tuberculosis. Preliminary diagnosis was performed using Ziehl-Neelsen staining followed by liquid culture in BacT/ALERT three-dimensional system. A total of 906 positive cultures obtained were differentiated as either NTM or Mycobacterium tuberculosis complex using a biochemical and MPT64 antigen test. Further identification of NTM species was confirmed with a line probe assay.
RESULTS
Out of 906 cultures isolates, 263 (29.0%) were confirmed as NTM and 643 (71.0%) were identified as Mycobacterium tuberculosis complex. A total of 79.4% of the NTM were recovered from pulmonary and 18.2% from extrapulmonary specimens. The diversity of NTM species was high (13 species) and predominated by Mycobacterium abscessus (31.3%) followed by Mycobacterium fortuitum (22%), Mycobacterium intracellulare (13.6%), Mycobacterium chelonae (9.1%), however, M. abscessus and M. fortuitum were the predominant species in both types of clinical isolates. Men (60.4%) and older patients aged greater than 55years were the predominated risk group for NTM infection.
CONCLUSION
The high prevalence and species diversity of NTM suggests the need for immediate and accurate characterization of NTM for proper treatment and management of patients.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Child; Child, Preschool; Female; Genetic Variation; Humans; India; Infant; Male; Middle Aged; Molecular Diagnostic Techniques; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Prevalence; Prospective Studies; Tertiary Care Centers; Young Adult
PubMed: 27847012
DOI: 10.1016/j.ijmyco.2016.06.008 -
Nontuberculous Mycobacteria Show Differential Infectivity and Use Phospholipids to Antagonize LL-37.American Journal of Respiratory Cell... Mar 2020Comparisons of infectivity among the clinically important nontuberculous mycobacteria (NTM) species have not been explored in great depth. Rapid-growing mycobacteria,... (Comparative Study)
Comparative Study
Comparisons of infectivity among the clinically important nontuberculous mycobacteria (NTM) species have not been explored in great depth. Rapid-growing mycobacteria, including and , can cause indolent but progressive lung disease. Slow-growing members of the complex are the most common group of NTM to cause lung disease, and molecular approaches can now distinguish between several distinct species of complex including , , , and . Differential infectivity among these NTM species may, in part, account for differences in clinical outcomes and response to treatment; thus, knowing the relative infectivity of particular isolates could increase prognostication accuracy and enhance personalized treatment. Using human macrophages, we investigated the infectivity and virulence of nine NTM species, as well as multiple isolates of the same species. We also assessed their capacity to evade killing by the antibacterial peptide cathelicidin (LL-37). We discovered that the ability of different NTM species to infect macrophages varied among the species and among isolates of the same species. Our biochemical assays implicate modified phospholipids, which may include a phosphatidylinositol or cardiolipin backbone, as candidate antagonists of LL-37 antibacterial activity. The high variation in infectivity and virulence of NTM strains suggests that more detailed microbiological and biochemical characterizations are necessary to increase our knowledge of NTM pathogenesis.
Topics: Antimicrobial Cationic Peptides; Cell Membrane; Chromatography, Thin Layer; Escherichia coli; Humans; Immune Evasion; Macrophages; Macrophages, Alveolar; Membrane Lipids; Nontuberculous Mycobacteria; Phospholipids; Phylogeny; Species Specificity; THP-1 Cells; Virulence; Cathelicidins
PubMed: 31545652
DOI: 10.1165/rcmb.2018-0278OC -
Journal of Dairy Science Jan 2021Nontuberculous mycobacteria (NTM) compose a group of mycobacteria that do not belong to the Mycobacterium tuberculosis complex group. They are frequently isolated from...
Nontuberculous mycobacteria (NTM) compose a group of mycobacteria that do not belong to the Mycobacterium tuberculosis complex group. They are frequently isolated from environmental samples such as water, soil, and, to a lesser extent, food samples. Isolates of NTM represent a major health threat to humans worldwide, especially those who have asthma or are immunocompromised. Human disease is acquired from environmental exposures and through consumption of NTM-contaminated food. The most common clinical manifestation of NTM disease in human is lung disease, but lymphatic, skin and soft tissue, and disseminated disease are also important. The main objective of the current study was to profile the farm-level contamination of cow milk with NTM by examining milk filters and bulk tank milk samples. Five different NTM species were isolated in one dairy herd in Wisconsin, with confirmed 16S rRNA genotypes including Mycobacterium fortuitum, Mycobacterium avium ssp. hominissuis, Mycobacterium abscessus, Mycobacterium simiae, and Mycobacterium avium ssp. paratuberculosis (Mycobacterium paratuberculosis). In tank milk samples, M. fortuitum was the predominant species in 48% of the samples, whereas M. chelonae/abscessus and M. fortuitum were the only 2 species obtained from 77 and 23% of the examined filters, respectively. Surprisingly, M. avium ssp. hominissuis, M. paratuberculosis, and M. simiae were isolated from 16.7, 10.4, and 4% of the examined milk samples, respectively, but not from milk filters. Interestingly, NTM isolates from human clinical cases in Wisconsin clustered very closely with those from milk samples. These findings suggest that the problem of NTM contamination is underestimated in dairy herds and could contribute to human infections with NTM. Overall, the study validates the use of bulk tank samples rather than milk filters to assess contamination of milk with NTM. Nontuberculous mycobacteria represent one type of pathogens that extensively contaminate raw milk at the farm level. The significance of our research is in evaluating the existence of NTM at the farm level and identifying a simple approach to examine the potential milk contamination with NTM members using tank milk or milk filters from dairy operations. In addition, we attempted to examine the potential link between NTM isolates found in the farm to those circulating in humans in Wisconsin.
Topics: Animals; Cattle; Female; Food Contamination; Food Storage; Genotype; Humans; Milk; Mycobacterium; Mycobacterium Infections, Nontuberculous; Mycobacterium avium subsp. paratuberculosis; Nontuberculous Mycobacteria; RNA, Ribosomal, 16S; Wisconsin
PubMed: 33162087
DOI: 10.3168/jds.2020-18214 -
Scientific Reports Mar 2018Four slowly growing mycobacteria isolates were isolated from the respiratory tract and soft tissue biopsies collected in four unrelated patients in Iran. Conventional...
Four slowly growing mycobacteria isolates were isolated from the respiratory tract and soft tissue biopsies collected in four unrelated patients in Iran. Conventional phenotypic tests indicated that these four isolates were identical to Mycobacterium lentiflavum while 16S rRNA gene sequencing yielded a unique sequence separated from that of M. lentiflavum. One representative strain AFP-003 was characterized as comprising a 6,121,237-bp chromosome (66.24% guanosine-cytosine content) encoding for 5,758 protein-coding genes, 50 tRNA and one complete rRNA operon. A total of 2,876 proteins were found to be associated with the mobilome, including 195 phage proteins. A total of 1,235 proteins were found to be associated with virulence and 96 with toxin/antitoxin systems. The genome of AFP-003 has the genetic potential to produce secondary metabolites, with 39 genes found to be associated with polyketide synthases and non-ribosomal peptide syntases and 11 genes encoding for bacteriocins. Two regions encoding putative prophages and three OriC regions separated by the dnaA gene were predicted. Strain AFP-003 genome exhibits 86% average nucleotide identity with Mycobacterium genavense genome. Genetic and genomic data indicate that strain AFP-003 is representative of a novel Mycobacterium species that we named Mycobacterium ahvazicum, the nineteenth species of the expanding Mycobacterium simiae complex.
Topics: Bacterial Proteins; DNA, Bacterial; DNA, Ribosomal; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 29515197
DOI: 10.1038/s41598-018-22526-z -
Journal of the Formosan Medical... Jun 2020Nontuberculous mycobacteria (NTM) are critical emerging global infectious pathogens. Though NTM can be mere colonizers when isolated from human specimens, NTM are also...
Nontuberculous mycobacteria (NTM) are critical emerging global infectious pathogens. Though NTM can be mere colonizers when isolated from human specimens, NTM are also responsible for diverse human infections. NTM-lung disease (NTM-LD) is the most common human disease entity. The present review aims to provide general insight into NTM-LD epidemiology in Taiwan. In reviewing NTM epidemiology in Taiwan, we discovered three distinguishing features. First, NTM disease incidence has increased in Taiwan over the past decade. Second, the distribution of NTM varies geographically in Taiwan. Mycobacterium avium-intracellulare complex (MAC) is the dominant species in northern Taiwan, whereas Mycobacterium abscessus complex and MAC may be equally dominant in southern Taiwan. Third, researchers in Taiwan have published valuable research investigating NTM among special patient populations, including patients in intensive care units, with ventilator dependency, with pulmonary tuberculosis, and who are infected with specific NTM species. The largest obstacle to clarifying NTM epidemiology in Taiwan may be the lack of routine NTM species identification in laboratories. Increased awareness of NTM diseases and acknowledgment that NTM species identification is crucial and guides clinical management are essential steps for facilitating the identification of NTM species in laboratories.
Topics: Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Mycobacterium avium Complex; Nontuberculous Mycobacteria; Taiwan
PubMed: 32482605
DOI: 10.1016/j.jfma.2020.05.019 -
BMC Infectious Diseases Jan 2024This study aimed to measure the prevalence of resistance to antimicrobial agents, and explore the risk factors associated with drug resistance by using nontuberculous...
OBJECTIVES
This study aimed to measure the prevalence of resistance to antimicrobial agents, and explore the risk factors associated with drug resistance by using nontuberculous Mycobacteria (NTM) isolates from China.
METHODS
A total of 335 NTM isolates were included in our analysis. Broth dilution method was used to determine in vitro drug susceptibility of NTM isolates.
RESULTS
Clarithromycin (CLA) was the most potent drug for Mycobacterium intracellulare (MI). The resistance rate of 244 MI isolates to CLA was 21%, yielding a minimum inhibitory concentrations (MIC) and MIC of 8 and 64 mg/L, respectively. 51% of 244 MI isolates exhibited resistance to amikacin (AMK). For 91 Mycobacterium abscessus complex (MABC) isolates, 6 (7%) and 49 (54%) isolates were categorized as resistant to CLA at day 3 and 14, respectively. The resistance rate to CLA for Mycobacterium abscessus subspecies abscessus (MAA) was dramatically higher than that for Mycobacterium abscessus subspecies massiliense (MAM). Additionally, the percentage of patients presenting fever in the CLA-susceptible group was significantly higher than that in the CLA-resistant group.
CONCLUSIONS
Our data demonstrate that approximate one fifth of MI isolates are resistant to CLA. We have identified a higher proportion of CLA-resistant MAA isolates than MAM. The patients caused by CLA-resistant MI are at low risk for presenting with fever relative to CLA-susceptible group.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium avium Complex; Mycobacterium abscessus; China; Amikacin; Clarithromycin; Fever
PubMed: 38262940
DOI: 10.1186/s12879-024-09016-6 -
Scientific Reports Aug 2017Mycobacteria are classified into two groups, fast- and slow-growing. Often, fast-growing mycobacteria are assumed to have a higher metabolic activity than their slower...
Mycobacteria are classified into two groups, fast- and slow-growing. Often, fast-growing mycobacteria are assumed to have a higher metabolic activity than their slower counterparts, but in mature biofilms this assumption might not be correct. Indeed, when measuring the metabolic activity of mycobacterial biofilms with two independent non-invasive techniques (isothermal microcalorimetry and tunable diode laser absorption spectrometry), mature biofilms of slow- and fast-growing species appeared more alike than expected. Metabolic heat production rate was 2298 ± 181 µW for M. smegmatis and 792 ± 81 µW for M. phlei, while M. tuberculosis and M. bovis metabolic heat production rates were between these values. These small differences were further confirmed by similar oxygen consumption rates (3.3 ± 0.2 nMole/s and 1.7 ± 0.3 nMole/s for M. smegmatis and M. tuberculosis, respectively). These data suggest that the metabolic potential of slow-growing mycobacterial biofilms has been underestimated, particularly for pathogenic species.
Topics: Biofilms; Carbon Dioxide; Energy Metabolism; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Oxygen
PubMed: 28835629
DOI: 10.1038/s41598-017-10019-4 -
Applied and Environmental Microbiology Oct 2020Environmental nontuberculous mycobacteria (NTM), with the potential to cause opportunistic lung infections, can reside in soil. This might be particularly relevant in...
Environmental nontuberculous mycobacteria (NTM), with the potential to cause opportunistic lung infections, can reside in soil. This might be particularly relevant in Hawai'i, a geographic hot spot for NTM infections and whose soil composition differs from many other areas of the world. Soil components are likely to contribute to NTM prevalence in certain niches as food sources or attachment scaffolds, but the particular types of soils, clays, and minerals that impact NTM growth are not well-defined. Hawai'i soil and chemically weathered rock (saprolite) samples were examined to characterize the microbiome and quantify 11 mineralogical features as well as soil pH. Machine learning methods were applied to identify important soil features influencing the presence of NTM. Next, these features were directly tested by incubating synthetic clays and minerals in the presence of and isolates recovered from the Hawai'i environment, and changes in bacterial growth were determined. Of the components examined, synthetic gibbsite, a mineral form of aluminum hydroxide, inhibited the growth of both and , while other minerals tested showed differential effects on each species. For example, (but not ) growth was significantly higher in the presence of hematite, an iron oxide mineral. In contrast, (but not ) counts were significantly reduced in the presence of birnessite, a manganese-containing mineral. These studies shed new light on the mineralogic features that promote or inhibit the presence of Hawai'i NTM in Hawai'i soil. Globally and in the United States, the prevalence of NTM pulmonary disease-a potentially life-threatening but underdiagnosed chronic illness-is prominently rising. While NTM are ubiquitous in the environment, including in soil, the specific soil components that promote or inhibit NTM growth have not been elucidated. We hypothesized that NTM culture-positive soil contains minerals that promote NTM growth Because Hawai'i is a hot spot for NTM and a unique geographic archipelago, we examined the composition of Hawai'i soil and identified individual clay, iron, and manganese minerals associated with NTM. Next, individual components were evaluated for their ability to directly modulate NTM growth in culture. In general, gibbsite and some manganese oxides were shown to decrease NTM, whereas iron-containing minerals were associated with higher NTM counts. These data provide new information to guide future analyses of soil-associated factors impacting persistence of these soil bacteria.
Topics: Hawaii; Nontuberculous Mycobacteria; Soil; Soil Microbiology; Species Specificity
PubMed: 32859599
DOI: 10.1128/AEM.00121-20 -
International Journal of Systematic and... Aug 2011A previously undescribed, rapid-growing, non-chromogenic Mycobacterium isolate from a goat lung lesion in Algeria is reported. Biochemical and molecular tools were used...
A previously undescribed, rapid-growing, non-chromogenic Mycobacterium isolate from a goat lung lesion in Algeria is reported. Biochemical and molecular tools were used for its complete description and showed its affiliation to the Mycobacterium terrae complex. 16S rRNA, rpoB and hsp65 gene sequences were unique. Phylogenetic analyses showed a close relationship with M. terrae sensu stricto and Mycobacterium senuense. Culture and biochemical characteristics were generally similar to those of M. terrae and M. senuense. However, in contrast to M. terrae and M. senuense, the isolate was positive for urease production and had faster growth. The mycolic acid profile was distinct from those of M. terrae and M. senuense, thus further supporting the new taxonomic position of the isolate. We propose the name Mycobacterium algericum sp. nov. for this novel species. The type strain is TBE 500028/10(T) ( = Bejaia(T) = CIP 110121(T) = DSM 45454(T)).
Topics: Animals; Bacterial Proteins; DNA, Bacterial; DNA, Ribosomal; Goat Diseases; Goats; Lung; Molecular Sequence Data; Mycobacterium; Mycobacterium Infections; Nontuberculous Mycobacteria; Phylogeny; RNA, Ribosomal, 16S
PubMed: 20833885
DOI: 10.1099/ijs.0.024851-0