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Journal of Applied Microbiology Apr 2022Mycobacterium abscessus subsp. abscessus (MABS) is an emerging, opportunistic pathogen found globally in freshwater biofilms and soil. Typically, isolates are treated as...
AIMS
Mycobacterium abscessus subsp. abscessus (MABS) is an emerging, opportunistic pathogen found globally in freshwater biofilms and soil. Typically, isolates are treated as a uniform group of organisms and very little is known about their comparative survival in healthy host cells. We posit that environmentally- and clinically derived isolates, show differential infectivity in immune cells and resistance to innate defenses.
METHODS AND RESULTS
Six MABS isolates were tested including three water biofilm/soil and three sputum-derived isolates. A clinical MABS type strain and an environmental isolate of Arthrobacter were also included. MABS counts were significantly higher compared to Arthrobacter after co-culture with Acanthamoeba lenticulata, BEAS-2B epithelial cells, alveolar macrophages and the THP-1 macrophage cell line. A rough sputum-derived MABS isolate emerged as an isolate with higher virulence compared to others tested, as both a pellicle and cord former, survivor in the human cell models tested, inducer of high and prolonged production of pro-inflammatory cytokines, and the capacity to evade LL-37.
CONCLUSIONS
Findings support intraspecies variation between MABS isolates.
SIGNIFICANCE AND IMPACT OF THE STUDY
These data indicate subversion of host immune defenses by environmental and clinical MABS isolates is nuanced and maybe isolate dependent, providing new information regarding the pathogenesis of NTM infections.
Topics: Biofilms; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Nontuberculous Mycobacteria; Sputum; Virulence
PubMed: 34919308
DOI: 10.1111/jam.15416 -
Infection Control and Hospital... Jul 2017OBJECTIVE Activated alkaline glutaraldehyde (GTA) remains one of the most widely used high-level disinfectants worldwide. However, several reports have highlighted the...
OBJECTIVE Activated alkaline glutaraldehyde (GTA) remains one of the most widely used high-level disinfectants worldwide. However, several reports have highlighted the potential for nontuberculous mycobacteria to develop high-level resistance to this product. Because aldehyde resistance may lead to cross-resistance to other biocides, we investigated the susceptibility profile of GTA-resistant Mycobacterium chelonae and M. abscessus isolates to various disinfectant chemistries. METHODS High-level disinfectants commonly used in the reprocessing of endoscopes and other heat-sensitive, semicritical medical equipment, including different formulations of aldehyde-based products and oxidizing agents, were tested against 10 slow- and fast-growing, GTA-susceptible and GTA-resistant, Mycobacterium isolates in suspension tests and carrier tests at different temperatures. RESULTS While peracetic acid- and hydrogen peroxide-based disinfectants (S40, Resert XL, Reliance DG) efficiently killed all of the Mycobacterium isolates, GTA- and ortho-phthalaldehyde-based products (ie, Cidex, Aldahol, Cidex OPA) showed variable efficacy against GTA-resistant strains despite the ability of some formulations (Aldahol) to overcome the resistance of some of these isolates, especially when the temperature was increased from 20°C to 25°C. CONCLUSIONS Application permitting, oxidizing chemistries may provide a safe alternative to aldehyde-based products, particularly in GTA-resistant mycobacterial outbreaks. Infect Control Hosp Epidemiol 2017;38:784-791.
Topics: Aldehydes; Disinfectants; Drug Resistance, Bacterial; Glutaral; Microbial Sensitivity Tests; Mycobacterium abscessus; Mycobacterium chelonae; Nontuberculous Mycobacteria; Peracetic Acid; Temperature
PubMed: 28462746
DOI: 10.1017/ice.2017.75 -
PloS One 2015Clarithromycin was considered the cornerstone for the treatment of Mycobacterium abscessus complex infections. Genetic resistance mechanisms have been described and many...
PURPOSE
Clarithromycin was considered the cornerstone for the treatment of Mycobacterium abscessus complex infections. Genetic resistance mechanisms have been described and many experts propose amikacin as an alternative. Nevertheless, clarithromycin has several advantages; therefore, it is necessary to identify the non-functional erm(41) allele to determine the most suitable treatment. The aims of this study were to characterize the molecular mechanisms of clarithromycin resistance in a collection of Mycobacterium abscessus complex isolates and to verify the relationship between these mechanisms and the antibiogram.
MATERIALS AND METHODS
Clinical isolates of M. abscessus complex (n = 22) from 16 patients were identified using four housekeeping genes (rpoB, secA1, sodA and hsp65), and their genetic resistance was characterized by studying erm(41) and rrl genes. Nine strains were recovered from the clinical isolates and subjected to E-test and microdilution clarithromycin susceptibility tests, with readings at 3, 7 and 14 days.
RESULTS
We classified 11/16 (68.8%) M. abscessus subsp. abscessus, 4/16 (25.0%) M. abscessus subsp. bolletii, and 1/16 (6.3%) M. abscessus subsp. massiliense. T28 erm(41) allele was observed in 8 Mycobacterium abscessus subps. abscessus and 3 Mycobacterium abscessus subsp. bolletii. One strain of M. abscessus subsp. bolletii had an erm(41) gene truncated and was susceptible to clarithromycin. No mutations were observed in rrl gene first isolates. In three patients, follow-up of initial rrl wild-type strains showed acquired resistance.
CONCLUSIONS
Most clinical isolates of M. abscessus complex had inducible resistance to clarithromycin and total absence of constitutive resistance. Our findings showed that the acquisition of resistance mutations in rrl gene was associated with functional and non-functional erm(41) gene. Caution is needed when using erm(41) sequencing alone to identify M. abscessus subspecies. This study reports an acquired mutation at position 2057 of rrl gene, conferring medium-low clarithromycin constitutive resistance.
Topics: Anti-Bacterial Agents; Clarithromycin; Drug Resistance, Bacterial; Genes, Bacterial; Humans; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 26448181
DOI: 10.1371/journal.pone.0140166 -
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 -
Acta Medica Portuguesa Dec 1999The isolation of nontuberculous mycobacteria was considered for many years as a result of contamination or transient colonization. The role of these bacteria in human... (Review)
Review
The isolation of nontuberculous mycobacteria was considered for many years as a result of contamination or transient colonization. The role of these bacteria in human disease was recognized only after 1950. They were present almost exclusively in patients with underlying pulmonary pathology and were rare. The prevalence of disease caused by nontuberculous mycobacteria was dramatically increased with the AIDS epidemic. Disseminated infection with MAC and other atypical mycobacteria is nowadays a frequent complication of AIDS. The authors describe some epidemiological and clinical features of these nontuberculous mycobacteria emphasizing the role of MAC and make some considerations about the diagnosis, prophylaxis and treatment of these diseases. The authors end by presenting their own clinical experience.
Topics: Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 10892440
DOI: No ID Found -
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 -
Clinical Infectious Diseases : An... Apr 2008The clinical relevance of Mycobacterium szulgai isolates is unknown, and available literature focuses on case reports of M. szulgai disease. We assessed the clinical...
BACKGROUND
The clinical relevance of Mycobacterium szulgai isolates is unknown, and available literature focuses on case reports of M. szulgai disease. We assessed the clinical relevance of M. szulgai isolated from patients in The Netherlands.
METHODS
We reviewed medical files for all 21 patients in The Netherlands from whom M. szulgai was isolated during 1999-2006, applying the diagnostic criteria of the American Thoracic Society for nontuberculous mycobacterial infection. Random amplified polymorphic DNA genotyping was performed using IS986, OPA-2, and OPA-18 as primers.
RESULTS
Of the 21 patients, 16 (76%) met the American Thoracic Society diagnostic criteria and were thus likely to have M. szulgai disease. Pulmonary M. szulgai disease was the most common presentation, with extrapulmonary disease restricted to patients with an impaired systemic immunity. Although treatment regimens varied in content and duration, the outcomes were mostly favorable. Both overtreatment and undertreatment were noticed. Random amplified polymorphic DNA genotyping revealed a higher degree of interpatient variability, with limited intrapatient variability, suggesting persisting monoclonal infection and good reproducibility. No genotype was associated with clinical relevance.
CONCLUSIONS
Clinical isolation of M. szulgai generally represents true disease and demands careful follow-up. Extrapulmonary disease occurs in patients with impaired immunity. Adherence to diagnostic guidelines can be improved.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antitubercular Agents; DNA, Bacterial; Female; Genotype; Humans; Isoniazid; Male; Middle Aged; Mycobacterium Infections, Nontuberculous; Netherlands; Nontuberculous Mycobacteria; Random Amplified Polymorphic DNA Technique
PubMed: 18444856
DOI: 10.1086/529443 -
Nontuberculous mycobacteria isolation from sputum specimens: A retrospective analysis of 1061 cases.International Journal of... 2023In recent years, with the development of laboratory methods, the frequency of nontuberculosis mycobacteria (NTM) infections has increased. The primary aim of this study...
BACKGROUND
In recent years, with the development of laboratory methods, the frequency of nontuberculosis mycobacteria (NTM) infections has increased. The primary aim of this study was to evaluate the clinical significance of therapeutic drug monitoring (TDM) growths in respiratory samples, and the secondary aim was to evaluate the treatment regimens and treatment outcomes of treatment for TDM disease.
METHODS
This study was a retrospective cohort study. Persons with NTM growth in respiratory samples admitted to the reference hospital between 2009 and 2020 were included in this study. Samples detected as NTM by the immunochromatographic rapid diagnostic test, those requested by the clinicians, species were determined by the hsp65PCRREA method. The subjects were classified into 3 groups: patients with NTM infection who received treatment (135, 12.7%), those followed up without treatment (690, 65.1%), and a last group of patients with Mycobacterium tuberculosis (TB) complex strains were isolated and received TB treatment (236, 22.2%). Initiating NTM treatment was decided in accordance with the American Thoracic Society recommendations.
RESULTS
The mean ± standard deviation age of patients was 53.8 ± 16.5 years, and 749 (70.6%) were male. In total, 278 (26.2%) out of 1061 cases had identified, and the most frequent species were MAC (81; Mycobacterium avium: 39, Mycobacterium intracellulare: 39, and MAC: 3), Mycobacterium abscessus (67), Mycobacterium kansasii (48), Mycobacterium fortuitum (23), Mycobacterium chelonae (12), Mycobacterium gordonae (11), and Mycobacterium szulgai (11). In the NTM treatment group, 116 (85.9%) of 135 patients had multiple culture positivity. Previous TB treatment history had 51 (37.8%) of 135 patients, respiratory comorbidities were evident in 37 (27.4%) of 135 patients. Thorax computed tomography imaging in 84 patients revealed nodule 38 (45.2%), consolidation 46 (54.8%), cavity 52 (61.9%), and bronchiectasis 27 (32.1%). Treatment results in the NTM treatment group were as follows: ongoing treatment 14 (10.4%), cure 64 (47.4%), default 33 (24.4%), exitus 19 (14.1%), recurrence 3 (2.2%), and refractory disease 2 (1.5%).
CONCLUSION
This is a large case series evaluating the clinical significance of NTM growths and NTM treatment in Turkey. The clinical significance of NTM growth in respiratory samples is low. Treatment success rates of NTM patients who are treated are low. Treatment defaults and mortality rates are high. New drugs and new regimens are needed.
Topics: Humans; Male; Adult; Middle Aged; Aged; Female; Mycobacterium Infections, Nontuberculous; Retrospective Studies; Sputum; Mycobacterium; Mycobacterium chelonae
PubMed: 36926764
DOI: 10.4103/ijmy.ijmy_10_23 -
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 -
Internal Medicine (Tokyo, Japan) Apr 2000
Review
Topics: Drug Resistance, Microbial; Humans; Lung Diseases; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Rifampin
PubMed: 10801139
DOI: 10.2169/internalmedicine.39.277