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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 -
Journal of Applied Microbiology Nov 2006Ultraviolet (UV) irradiation for drinking water treatment was examined for inactivation and subsequent dark and photo-repair of Mycobacterium terrae.
AIM
Ultraviolet (UV) irradiation for drinking water treatment was examined for inactivation and subsequent dark and photo-repair of Mycobacterium terrae.
METHODS AND RESULTS
UV sources tested were low pressure (monochromatic, 254 nm) and medium pressure (polychromatic UV output) Hg lamps. UV exposure resulted in inactivation, and was followed by dark or photo-repair experiments. Inactivation and repair were quantified utilizing a molecular-based endonuclease sensitive site (ESS) assay and conventional colony forming unit (CFU) viability assay. Mycobacterium terrae was more resistant to UV disinfection compared to many other bacteria, with approximately 2-log reduction at a UV fluence of 10 mJ cm(-2) ; similar to UV inactivation of M. tuberculosis. There was no difference in inactivation between monochromatic or polychromatic UV lamps. Mycobacterium terrae did not undergo detectable dark repair. Photo-repair resulted in recovery from inactivation by approximately 0.5-log in less than 30 min for both UV lamp systems.
CONCLUSIONS
Mycobacterium terrae is able to photo-repair DNA damage within a short timeframe. The number of pyrimidine dimers induced by UV light were similar for Escherichia coli and M. terrae, however, this similarity did not hold true for viability results.
SIGNIFICANCE AND IMPACT OF THE STUDY
There is no practical difference between UV sources for disinfection or prevention of DNA repair for M. terrae. The capability of M. terrae to photo-repair UV damage fairly quickly is important for wastewater treatment applications where disinfected effluent is exposed to sunlight. Finally, molecular based assay results should be evaluated with respect to differences in the nucleic acid content of the test micro-organism.
Topics: Colony Count, Microbial; DNA Damage; DNA Repair; DNA, Bacterial; Disinfection; Dose-Response Relationship, Radiation; Nontuberculous Mycobacteria; Ultraviolet Rays; Water Microbiology
PubMed: 17040222
DOI: 10.1111/j.1365-2672.2006.03023.x -
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 -
The European Respiratory Journal Jun 2008The nontuberculous mycobacteria (NTM) exhibit heterogeneous pathogenicity in humans. Articles on known and potential human factors capable of producing susceptibility to... (Review)
Review
The nontuberculous mycobacteria (NTM) exhibit heterogeneous pathogenicity in humans. Articles on known and potential human factors capable of producing susceptibility to NTM lung disease (NTMLD) were identified by a systematic search of the medical literature, and are reviewed in the present study. Patients with pre-existing structural lung disease are known to be at risk of NTMLD. Other susceptible groups have become recognised since the 1980s, in particular middle-aged nonsmokers without previous lung disease (a group including those with Lady Windermere syndrome) and patients with genetically determined defects of cell-mediated immunity, including abnormalities of the interleukin-12/interferon-gamma axis, certain human leukocyte antigen alleles, cystic fibrosis transmembrane conductance regulator mutations, and polymorphisms of solute carrier 11A1 (or natural resistance-associated macrophage protein 1) and the vitamin D receptor. Information is also accruing about acquired systemic causes of susceptibility to NTMLD, including inhibitory antibodies directed against interferon-gamma, post-menopausal waning of endogenous oestrogen levels, coeliac disease and exposure to use of dietary phyto-oestrogens. It is not known whether immunosuppressive factors, such as oral corticosteroid treatment, chronic renal failure, diabetes mellitus and other known risk factors for pulmonary tuberculosis, are also risk factors for the development of NTMLD. Caution is appropriate in managing such patients.
Topics: Disease Susceptibility; Humans; Immunocompromised Host; Lung Diseases; Lung Transplantation; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 18515557
DOI: 10.1183/09031936.00140007 -
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 2022The increasing worldwide incidence of nontuberculous mycobacterial lung disease (NTM-LD) and the similarity of its manifestations to those of tuberculosis (TB) pose huge... (Review)
Review
BACKGROUND
The increasing worldwide incidence of nontuberculous mycobacterial lung disease (NTM-LD) and the similarity of its manifestations to those of tuberculosis (TB) pose huge challenges in the diagnosis and treatment of NTM-LD, which is commonly misdiagnosed and mistreated as TB. Proper diagnosis and treatment at an early stage can greatly improve patient outcomes.
CASE PRESENTATION
was identified by mNGS in lung tissue of case 1 and bronchioalveolar fluid from case 2 that was not identified using conventional microbiological methods. Multiple NTM species were detected in the blood mNGS samples from case 3 who had disseminated NTM infection. Although NTM was isolated from blood culture, conventional methods failed to identify the organisms to the level of species. All three patients were suffering from and being treated for myelodysplastic syndrome, rheumatoid arthritis, systemic lupus erythematosus, or acute lymphoblastic leukemia, making them immunosuppressed and susceptible to NTM infections. Case 1 and Case 2 significantly improved after anti-NTM treatment, but case 3 succumbed to the infection due to her underlying medical illness despite aggressive treatment.
CONCLUSIONS
The cases in this study demonstrate the effectiveness of mNGS in facilitating and improving the clinical diagnosis of NTM infections. We propose combining mNGS with traditional diagnostic methods to identify pathogens at the early stages of the disease so that targeted treatment can be implemented.
Topics: Humans; Female; Nontuberculous Mycobacteria; High-Throughput Nucleotide Sequencing; Microbiological Techniques; Immunocompromised Host
PubMed: 36452947
DOI: 10.3389/fpubh.2022.972280