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Journal of Applied Microbiology Sep 2013Measure adherence and biofilm formation by cells of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium abscessus on common household plumbing materials...
AIMS
Measure adherence and biofilm formation by cells of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium abscessus on common household plumbing materials namely stainless steel, glass, zinc-galvanized steel, copper and polyvinyl chloride (PVC).
METHODS AND RESULTS
Coupons in a CDC biofilm reactor were exposed to cell suspensions containing 10(5) NTM colony forming units (CFU) per ml and adherence measured for 6 h. Biofilm formation (increased numbers of adherent CFU) was measured weekly to 21 days in the absence of substantial numbers of suspended mycobacterial cells. Adherence was rapid and substantial with 2000-15 000 CFU cm(-2) adhering within 1-6 h at room temperature. Biofilm numbers reached as high as 10(7) CFU cm(-2) . Biofilm-grown cells of Myco. avium were more adherent compared with suspension-grown cells.
CONCLUSIONS
Mycobacterium avium, Myco. intracellulare and Myco. abscessus readily adhered and formed biofilms on all types of plumbing materials. Factors influencing adherence and biofilm formation were species, plumbing material and prior growth.
Topics: Bacterial Adhesion; Biofilms; Household Articles; Humans; Mycobacterium avium; Mycobacterium avium Complex; Nontuberculous Mycobacteria; Sanitary Engineering; United States
PubMed: 23742161
DOI: 10.1111/jam.12272 -
Antimicrobial Agents and Chemotherapy Dec 1986We determined the MICs of ethambutol for both Mycobacterium avium and Mycobacterium tuberculosis strains by using broth dilution (7H12 broth, radiometric method) and... (Comparative Study)
Comparative Study
We determined the MICs of ethambutol for both Mycobacterium avium and Mycobacterium tuberculosis strains by using broth dilution (7H12 broth, radiometric method) and agar dilution (7H11 agar) methods. We found the MICs to be much lower in liquid than in solid medium. The broth-determined MICs for susceptible M. tuberculosis and most of the M. avium strains were comparable to the levels in blood of patients, being lower than the peak levels. We propose that the MICs, determined radiometrically in in 7H12 broth, be considered as tentative criteria for susceptibility testing of M. avium isolates in future clinical trials. The use of these values instead of critical concentrations should also be considered as an alternative to the conventional susceptibility testing method in chemotherapy of tuberculosis. Ethambutol produced bactericidal effects against both M. tuberculosis and M. avium, and the MIC/MBC ratios were in the same range for both species when MICs and MBCs were tested in 7H12 broth by conventional sampling and plating.
Topics: Culture Media; Ethambutol; Humans; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium tuberculosis
PubMed: 3101588
DOI: 10.1128/AAC.30.6.927 -
PloS One 2012Mycobacterium avium is the principal etiologic agent of non-tuberculous lymphadenitis in children. It is also a known pathogen for birds and other animals. Genetic...
BACKGROUND
Mycobacterium avium is the principal etiologic agent of non-tuberculous lymphadenitis in children. It is also a known pathogen for birds and other animals. Genetic typing of M. avium isolates has led to a proposal to expand the set of subspecies to include M. avium subsp. hominissuis. Isolates associated with disease in humans belong to this subspecies.
METHODOLOGY/PRINCIPAL FINDINGS
Peripheral blood mononuclear cells from six healthy blood donors were stimulated in vitro with ten isolates of M. avium avium and 11 isolates of M. avium hominissuis followed by multiplex bead array quantification of cytokines in supernatants. M. avium hominissuis isolates induced significantly more IL-10 and significantly less IL-12p70, TNF, IFN-γ and IL-17 when compared to M. avium avium isolates. All strains induced high levels of IL-17, but had very low levels of IL-12p70.
CONCLUSION/SIGNIFICANCE
The strong association between M. avium subsp. hominissuis and disease in humans and the clear differences in the human immune response to M. avium subsp. hominissuis compared to M. avium subsp. avium isolates, as demonstrated in this study, suggest that genetic differences between M. avium isolates play an important role in the pathogenicity in humans.
Topics: Humans; Interferon-gamma; Interleukins; Leukocytes, Mononuclear; Mycobacterium avium; Tuberculosis; Tumor Necrosis Factor-alpha
PubMed: 22506018
DOI: 10.1371/journal.pone.0034391 -
Viruses Dec 2023Johne's disease (JD), a chronic infectious enteritis of ruminants, causes major economic losses in the dairy industry globally. This enteritis is caused by subsp....
Johne's disease (JD), a chronic infectious enteritis of ruminants, causes major economic losses in the dairy industry globally. This enteritis is caused by subsp. (MAP). Currently there is no cure for JD and test-based culling has proved ineffective at preventing the spread. To isolate new mycobacteriophages (mbps) that can potentially be used to control JD transmission and infection on dairy farms, we optimized an isolation protocol by fecal spiking and the testing of different isolation solution compositions. Using this protocol, we successfully enhanced the yield of mbps from spiked fecal samples, elevating it from less than 1% to 59%. With this method, we isolated 14 mbps from 475 environmental samples collected from MAP-positive dairy farms, after in-sample enrichment with MAP and the fast-growing . The sample sources included soil, manure pits, lactation barns, feces, milk, and drain water. After fingerprinting these mbps by restriction enzyme profiling, we concluded that 12 were distinct and novel. Further characterization of their host range revealed that eight were capable of lysing multiple MAP strains. We also studied the cross-resistance, lysogeny, the effect of pH and their antimycobacterial properties in milk replacer. Each novel mbp showed limited cross-resistance and prophage immunity and showed no reduction in the titer in a range of pHs after 4 h. The novel phages were also able to reduce the mycobacterial counts to zero after 8 h in milk replacer. In conclusion, these novel mbps could be considered to be used in the control strategies of JD on farms.
Topics: Female; Animals; Mycobacterium avium subsp. paratuberculosis; Mycobacteriophages; Bacteriophages; Farms; Enteritis
PubMed: 38257721
DOI: 10.3390/v16010020 -
The European Respiratory Journal Mar 2017
Topics: Humans; Lung Diseases; Mycobacterium avium; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Sputum
PubMed: 28275180
DOI: 10.1183/13993003.00110-2017 -
Scientific Data Dec 2018Infection with Mycobacterium avium is a significant cause of morbidity and its treatment requires the use of multiple antibiotics for more than 12 months. In the current...
Infection with Mycobacterium avium is a significant cause of morbidity and its treatment requires the use of multiple antibiotics for more than 12 months. In the current work, we provide the genome sequence, gene annotations, gene ontology annotations, and protein homology data for M. avium strain 109 (MAC109), which has been used extensively in preclinical studies. The de novo assembled genome consists of a circular chromosome of length 5,188,883 bp and two circular plasmids of sizes 147,100 bp and 16,516 bp. We have named the plasmids pMAC109a and pMAC109b, respectively. Based on its genome, we confirm that MAC109 should be classified as Mycobacterium avium subsp. hominissuis. Using genome annotation software, we identified 4,841 coding sequences and annotated these with Gene Ontology (GO) terms. Additionally, we wrote software to generate a database of homologous proteins among MAC109 and eight other commonly used mycobacterial laboratory strains. The resulting database may be useful for translating genetic data between various strains of mycobacteria, and the software may be applied readily to other organisms.
Topics: Databases, Factual; Genome, Bacterial; Mycobacterium avium; Phylogeny; Sequence Analysis, DNA
PubMed: 30512015
DOI: 10.1038/sdata.2018.277 -
PloS One 2015Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to...
Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to treat. In recent years, extracellular DNA (eDNA) has been found to be a major component of bacterial biofilms, including many pathogens involved in biofilm-associated infections. To date, eDNA has not been described as a component of mycobacterial biofilms. In this study, we identified and characterized eDNA in a high biofilm-producing strain of Mycobacterium avium subsp. hominissuis (MAH). In addition, we surveyed for presence of eDNA in various MAH strains and other nontuberculous mycobacteria. Biofilms of MAH A5 (high biofilm-producing strain) and MAH 104 (reference strain) were established at 22°C and 37°C on abiotic surfaces. Acellular biofilm matrix and supernatant from MAH A5 7 day-old biofilms both possess abundant eDNA, however very little eDNA was found in MAH 104 biofilms. A survey of MAH clinical isolates and other clinically relevant nontuberculous mycobacterial species revealed many species and strains that also produce eDNA. RAPD analysis demonstrated that eDNA resembles genomic DNA. Treatment with DNase I reduced the biomass of MAH A5 biofilms when added upon biofilm formation or to an already established biofilm both on abiotic surfaces and on top of human pharyngeal epithelial cells. Furthermore, co-treatment of an established biofilm with DNase 1 and either moxifloxacin or clarithromycin significantly increased the susceptibility of the bacteria within the biofilm to these clinically used antimicrobials. Collectively, our results describe an additional matrix component of mycobacterial biofilms and a potential new target to help treat biofilm-associated nontuberculous mycobacterial infections.
Topics: Anti-Bacterial Agents; Biofilms; Cell Line; Clarithromycin; DNA, Bacterial; Deoxyribonuclease I; Drug Resistance, Bacterial; Epithelial Cells; Fluoroquinolones; Humans; Moxifloxacin; Mycobacterium avium
PubMed: 26010725
DOI: 10.1371/journal.pone.0128772 -
Journal of Clinical Microbiology May 2015Accurate identification of mycobacterial species and subspecies is essential to evaluate their significance and to perform epidemiological studies. The subspecies of...
Accurate identification of mycobacterial species and subspecies is essential to evaluate their significance and to perform epidemiological studies. The subspecies of Mycobacterium avium have different attributes but coincide in their zoonotic potential. Our knowledge about M. avium subsp. silvaticum is limited, since its identification is uncertain. Mycobacterium avium subsp. avium and M. avium subsp. silvaticum can be discriminated from each other based only on phenotypic characteristics, as they have almost identical genome sequences. Here we describe the development of a diagnostic method which enables the molecular identification of M. avium subsp. silvaticum and discrimination from M. avium subsp. avium based on genomic differences in a duplex high-resolution melt and M. avium subsp. silvaticum-specific mismatch real-time PCR. The developed assay was tested on reference strains and 199 field isolates, which were analyzed by phenotypic methods previously. This assay not only identified all 63 M. avium subsp. silvaticum and 138 M. avium subsp. avium strains correctly but also enabled the detection of mixed M. avium subsp. avium-M. avium subsp. silvaticum cultures. This is the first time that such a large panel of strains has been analyzed, and we also report the first isolation of M. avium subsp. silvaticum from red fox, red deer, wild boar, cattle, and badger. This assay is reliable, rapid, simple, inexpensive, and robust. It eliminates the long-existing problem of ambiguous phenotypic identification and opens up the possibility for detailed and comprehensive strain studies.
Topics: Animals; Animals, Domestic; Base Pair Mismatch; Birds; Costs and Cost Analysis; DNA, Bacterial; Genotyping Techniques; Mammals; Microbiological Techniques; Molecular Diagnostic Techniques; Mycobacterium avium; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Time Factors; Transition Temperature; Tuberculosis
PubMed: 25740770
DOI: 10.1128/JCM.03556-14 -
International Journal of Infectious... Sep 2020Characteristics of the Mycobacterium avium-intracellulare complex pulmonary disease (MAC-PD) caused by distinct subspecies remain uncertain.
OBJECTIVES
Characteristics of the Mycobacterium avium-intracellulare complex pulmonary disease (MAC-PD) caused by distinct subspecies remain uncertain.
METHODS
This study was conducted from 2013-2015 in three hospitals in Taiwan.
RESULTS
Among the 144 patients with MAC-PD, 57 (39.6%), 37 (25.7%), 37 (25.7%), and 13 (9.0%) were infected with Mycobacterium intracellulare subspecies intracellulare (MIsI), Mycobacterium avium subspecies hominissuis (MAsH), Mycobacterium intracellulare subspecies chimaera (MIsC), and others, respectively. Patients with MAsH-PD were younger (p = 0.010) with higher human immunodeficiency virus infection rates (27.0%, 0.0%, 0.0%, and 7.7% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p < 0.001). Twenty-two (15.3%) patients reported spontaneous culture-negative conversion, but 15 (10.4%) and 33 (22.9%) patients developed radiographic progression and unfavorable outcomes, especially MAsH-PD. The susceptibility rates to clarithromycin and inhaled amikacin were both 98.6%. MAsH demonstrated the lowest rate of resistance to moxifloxacin (66.7%, 97.3%, 89.1%, and 92.3% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p = 0.001) and MIsI isolates had the highest rate of resistance to intravenous amikacin (25%, 13.5%, 38.2%, and 15.4% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p = 0.024).
CONCLUSIONS
Pulmonary disease caused by distinct MAC subspecies had different outcomes and drug susceptibility. The local prevalence of species needs to be monitored.
Topics: Adult; Aged; Aged, 80 and over; Amikacin; Anti-Bacterial Agents; Clarithromycin; Drug Resistance, Bacterial; Female; Humans; Lung Diseases; Male; Microbial Sensitivity Tests; Middle Aged; Moxifloxacin; Mycobacterium avium; Mycobacterium avium-intracellulare Infection; Taiwan; Young Adult
PubMed: 32534139
DOI: 10.1016/j.ijid.2020.06.019 -
Antimicrobial Agents and Chemotherapy Feb 2016Multidrug therapy is a standard practice when treating infections by nontuberculous mycobacteria (NTM), but few treatment options exist. We conducted this study to...
Multidrug therapy is a standard practice when treating infections by nontuberculous mycobacteria (NTM), but few treatment options exist. We conducted this study to define the drug-drug interaction between clofazimine and both amikacin and clarithromycin and its contribution to NTM treatment. Mycobacterium abscessus and Mycobacterium avium type strains were used. Time-kill assays for clofazimine alone and combined with amikacin or clarithromycin were performed at concentrations of 0.25× to 2× MIC. Pharmacodynamic interactions were assessed by response surface model of Bliss independence (RSBI) and isobolographic analysis of Loewe additivity (ISLA), calculating the percentage of statistically significant Bliss interactions and interaction indices (I), respectively. Monte Carlo simulations with predicted human lung concentrations were used to calculate target attainment rates for combination and monotherapy regimens. Clofazimine alone was bacteriostatic for both NTM. Clofazimine-amikacin was synergistic against M. abscessus (I = 0.41; 95% confidence interval [CI], 0.29 to 0.55) and M. avium (I = 0.027; 95% CI, 0.007 to 0.048). Based on RSBI analysis, synergistic interactions of 28.4 to 29.0% and 23.2 to 56.7% were observed at 1× to 2× MIC and 0.25× to 2× MIC for M. abscessus and M. avium, respectively. Clofazimine-clarithromycin was also synergistic against M. abscessus (I = 0.53; 95% CI, 0.35 to 0.72) and M. avium (I = 0.16; 95% CI, 0.04 to 0.35), RSBI analysis showed 23.5% and 23.3 to 53.3% at 2× MIC and 0.25× to 0.5× MIC for M. abscessus and M. avium, respectively. Clofazimine prevented the regrowth observed with amikacin or clarithromycin alone. Target attainment rates of combination regimens were >60% higher than those of monotherapy regimens for M. abscessus and M. avium. The combination of clofazimine with amikacin or clarithromycin was synergistic in vitro. This suggests a potential role for clofazimine in treatment regimens that warrants further evaluation.
Topics: Amikacin; Anti-Bacterial Agents; Clarithromycin; Clofazimine; Drug Interactions; Drug Synergism; Drug Therapy, Combination; Microbial Sensitivity Tests; Monte Carlo Method; Mutation; Mycobacterium avium; Nontuberculous Mycobacteria
PubMed: 26643335
DOI: 10.1128/AAC.02615-15