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The American Review of Respiratory... Aug 1967
Topics: Animals; Bacteriological Techniques; Mice; Mycobacterium; Nontuberculous Mycobacteria; Time Factors
PubMed: 4952831
DOI: 10.1164/arrd.1967.96.2.299 -
Applied and Environmental Microbiology Jan 2010To prevent transmission of mycobacterial pathogens, medical devices must be disinfected by germicides with proven mycobactericidal activity. The quantitative carrier...
To prevent transmission of mycobacterial pathogens, medical devices must be disinfected by germicides with proven mycobactericidal activity. The quantitative carrier test EN 14563 provides an international standard for evaluation of the mycobactericidal activity of disinfectants under practical conditions. However, tests according to the EN 14563 standard are based on cultivation, and results are available only after 21 days. The aim of this study was to accelerate assessment of dosage and contact times of mycobactericidal preparations based on the EN 14563 standard. To this end, a gfp gene was constructed with a codon usage adapted for Mycobacterium tuberculosis. Expression of the gfp(m)(2+) gene in Mycobacterium terrae improved the detection sensitivity by 10-fold over that with a previously used reporter strain. Peracetic acid and a cation-active formulation were tested as commercially available disinfectants for medical devices. M. terrae expressing gfp(m)(2+) was used to determine dosage and contact times for the two test germicides. Fluorescence measurements correlated well with growth of the reporter strain, demonstrating that the fluorescence reliably indicated the number of viable cells. The fluorescence enabled us to determine the mycobactericidal efficacy of the test disinfectants according to the quantitative carrier test EN 14563 standard within at least 15 days. In conclusion, this study establishes gfp(m)(2+)-expressing M. terrae as a new reporter strain for reliable evaluation of mycobactericidal activities of disinfectants with a superior sensitivity and in a significantly shorter time than previously possible.
Topics: Codon; Disinfectants; Fluorescence; Green Fluorescent Proteins; Mycobacterium; Nontuberculous Mycobacteria
PubMed: 19948860
DOI: 10.1128/AEM.01660-09 -
International Journal of Hygiene and... Jan 2016Nontuberculous mycobacteria (NTM) are common bacteria in water and especially water supply distribution systems. Some species can cause infections, especially in...
BACKGROUND
Nontuberculous mycobacteria (NTM) are common bacteria in water and especially water supply distribution systems. Some species can cause infections, especially in immunocompromised patients and other risk groups. This study examined the frequency of occurrence of NTM in 135 household potable water samples collected from household water taps in Tenerife Island.
METHODS
Mycobacteria species were identified by polymerase chain reaction targeting the 16S rRNA and 16S-23S rRNA regions, and by double-reverse hybridization on a dipstick using colloidal gold-bound and membrane-bound probes (Speed-Oligo(®) Mycobacteria). Some species were identified by sequencing the gene that encodes the 16S rRNA region.
RESULTS
NTM were present in 47.4% of the samples. Mycobacterium fortuitum was the NTM isolated most frequently (70.3%), followed by Mycobacterium canariasense (6.3%) and Mycobacterium chelonae (6.3%). Other species were isolated at lower percentage frequencies.
CONCLUSION
We isolated and identified the species M. canariasense in water supplies for public consumption. This species has previously been reported only in hospital settings. The elevated presence of NTM in the water supply indicates that it may be a reservoir for infections caused by recently described species of mycobacteria.
Topics: Bacterial Typing Techniques; DNA, Bacterial; Drinking Water; Family Characteristics; Genes, Bacterial; Humans; Islands; Molecular Probes; Mycobacterium; Mycobacterium Infections; Nontuberculous Mycobacteria; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Spain; Water Microbiology; Water Supply
PubMed: 26324115
DOI: 10.1016/j.ijheh.2015.08.005 -
The Journal of Hospital Infection Oct 2016
Topics: Adult; Cystic Fibrosis; Disease Outbreaks; Electrophoresis, Gel, Pulsed-Field; Genotype; Hawaii; Humans; Molecular Epidemiology; Molecular Typing; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 27238609
DOI: 10.1016/j.jhin.2016.04.015 -
Applied and Environmental Microbiology Mar 2013Mycobacteria are isolated from soil and water environments, where free-living amoebae live. Free-living amoebae are bactericidal, yet some rapidly growing mycobacteria...
Mycobacteria are isolated from soil and water environments, where free-living amoebae live. Free-living amoebae are bactericidal, yet some rapidly growing mycobacteria are amoeba-resistant organisms that survive in the amoebal trophozoites and cysts. Such a capacity has not been studied for the environmental rapidly growing organism Mycobacterium gilvum. We investigated the ability of M. gilvum to survive in the trophozoites of Acanthamoeba polyphaga strain Linc-AP1 by using optical and electron microscopy and culture-based microbial enumerations in the presence of negative controls. We observed that 29% of A. polyphaga cells were infected by M. gilvum mycobacteria by 6 h postinfection. Surviving M. gilvum mycobacteria did not multiply and did not kill the amoebal trophozoites during a 5-day coculture. Extensive electron microscopy observations indicated that M. gilvum measured 1.4 ± 0.5 μm and failed to find M. gilvum organisms in the amoebal cysts. Further experimental study of two other rapidly growing mycobacteria, Mycobacterium rhodesiae and Mycobacterium thermoresistibile, indicated that both measured <2 μm and exhibited the same amoeba-mycobacterium relationships as M. gilvum. In general, we observed that mycobacteria measuring <2 μm do not significantly grow within and do not kill amoebal trophozoites, in contrast to mycobacteria measuring >2 μm (P < 0.05). The mechanisms underlying such an observation remain to be determined.
Topics: Acanthamoeba; Bacterial Load; Cell Survival; Microbial Viability; Microscopy; Nontuberculous Mycobacteria
PubMed: 23275502
DOI: 10.1128/AEM.03765-12 -
International Journal of... 2017Rapidly growing mycobacterial species (RGM) are increasingly being recognized as the cause of various superficial and deep infections in humans. Two of the species most...
BACKGROUND
Rapidly growing mycobacterial species (RGM) are increasingly being recognized as the cause of various superficial and deep infections in humans. Two of the species most frequently isolated from clinical specimens are Mycobacterium abscessus and Mycobacterium fortuitum. Both species are associated with antibiotic resistances that may complicate therapy. This paper describes the pattern of resistance to five antibiotics commonly prescribed for RGM infections, in M. abscessus and M. fortuitum isolated from Malaysian patients.
METHODS
The bacterial strains studied were examined with Etest strips to determine their minimum inhibitory concentrations (MICs) toward amikacin, ciprofloxacin, clarithromycin, imipenem, and linezolid.
RESULTS
Among 51 M. abscessus isolates examined by the Etest, the overall MICs of ciprofloxacin, imipenem, amikacin, clarithromycin, and linezolid showed resistance rates of 33.3%, 31.4%, 2.0%, 5.9%, and 21.6%, to the five antibiotics, respectively. M. abscessus subspecies abscessus was more resistant than M. abscessus subsp. massilience to ciprofloxacin, imipenem, and linezolid but was more susceptible to clarithromycin and amikacin. M. fortuitum isolates were significantly less resistant than M. abscessus to ciprofloxacin (3.6%) and imipenem (7.1%) but more resistant to clarithromycin (42.9%) and linezolid (39.3%).
CONCLUSION
A suitable combination therapy for Malaysian patients would be amikacin plus clarithromycin and ciprofloxacin, to cover infections by all three M. abscessus subspecies and M. fortuitum.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Drug Therapy, Combination; Humans; Malaysia; Microbial Sensitivity Tests; Microbial Viability; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 29171453
DOI: 10.4103/ijmy.ijmy_152_17 -
International Journal of Systematic and... May 2018Some species of non-tuberculous mycobacteria (NTM) have been reported to be opportunistic pathogens of animals and humans. Recently there has been an upsurge in the...
Some species of non-tuberculous mycobacteria (NTM) have been reported to be opportunistic pathogens of animals and humans. Recently there has been an upsurge in the number of cases of NTM infections, such that some NTM species are now recognized as pathogens of humans and animals. From a veterinary point of view, the major significance of NTM is the cross-reactive immune response they elicit against Mycobacterium bovis antigens, leading to misdiagnosis of bovine tuberculosis. Four NTM isolates were detected from a bovine nasal swab, soil and water, during an NTM survey in South Africa. These were all found using 16S rRNA gene sequence analysis to be closely related to Mycobacterium moriokaense. The isolates were further characterised by sequence analysis of the partial fragments of hsp65, rpoB and sodA. The genome of the type strain was also elucidated. Gene (16S rRNA, hsp65, rpoB and sodA) and protein sequence data analysis of 6 kDa early secretory antigenic target (ESAT 6) and 10 kDa culture filtrate protein (CFP-10) revealed that these isolates belong to a unique Mycobacterium species. Differences in phenotypic and biochemical traits between the isolates and closely related species further supported that these isolates belong to novel Mycobacterium species. We proposed the name Mycobacterium komaniense sp. nov. for this new species. The type strain is GPK 1020 (=CIP 110823T=ATCC BAA-2758).
Topics: Animals; Bacterial Typing Techniques; Cattle; DNA, Bacterial; Genes, Bacterial; Nontuberculous Mycobacteria; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; South Africa
PubMed: 29543151
DOI: 10.1099/ijsem.0.002707 -
Revista Argentina de Microbiologia 2016
Topics: Nontuberculous Mycobacteria
PubMed: 26702767
DOI: 10.1016/j.ram.2015.08.007 -
International Journal of Hygiene and... May 2019Non-tuberculous species of Mycobacterium are commonly found in a large diversity of water environments, and epidemiological studies suggest that natural or drinking... (Review)
Review
Non-tuberculous species of Mycobacterium are commonly found in a large diversity of water environments, and epidemiological studies suggest that natural or drinking waters are the principal sources of human contamination. Controlling non-tuberculous mycobacteria in water systems is therefore important to prevent infection with these micro-organisms. This review article summarizes the information and data published up to now on the factors favoring the presence of these bacteria in natural and artificial water systems, the effectiveness of water treatment means, and based on this information, identifies possible means to control the presence of non-tuberculous mycobacteria in drinking water.
Topics: Biofilms; Disinfection; Drinking Water; Environmental Monitoring; Nontuberculous Mycobacteria; Temperature; Water Microbiology; Water Purification
PubMed: 30670342
DOI: 10.1016/j.ijheh.2019.01.002 -
Indian Journal of Medical Microbiology 2016Mycobacterium kumamotonense is a novel, slow-growing non-chromogenic nontuberculous mycobacterium, which belongs to Mycobacterium terrae complex. We report, for the...
Mycobacterium kumamotonense is a novel, slow-growing non-chromogenic nontuberculous mycobacterium, which belongs to Mycobacterium terrae complex. We report, for the first time in Greece, the isolation of M. kumamotonense from an immunocompetent patient with pulmonary infection and latent tuberculosis. M. kumamotonense was identified by sequencing analysis of 16S rDNA and 65-kDa heat shock protein genes while by commercial molecular assays it was misidentified as Mycobacterium celatum. Antibiotic susceptibility testing was performed by the reference broth microdilution method. The strain was susceptible to amikacin, clarithromycin, rifampin, ciprofloxacin, moxifloxacin, rifabutin, ethambutol and linezolid.
Topics: Adult; Anti-Bacterial Agents; Bacterial Proteins; Chaperonin 60; Cluster Analysis; DNA, Bacterial; DNA, Ribosomal; Female; Greece; Humans; Latent Tuberculosis; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Phylogeny; Pneumonia, Bacterial; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 27080783
DOI: 10.4103/0255-0857.180356