Horizontal spread of mer operons among Gram-positive bacteria in natural environments

Bogdanova, E. S.; Bass, I. A.; Minakhin, Leonid; Petrová, Magdalena; Mindlin, S. Z.; Volodin, Alexander M.; Kalyaeva, E. S.; Tiedje, James M.; Hobman, Jon L.; Brown, Nigel L.; Nikiforov, Vadim

doi:10.1099/00221287-144-3-609

Cited by 74 publications

(69 citation statements)

References 56 publications

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“…2C). Multiple resistance genes are most often located in mobile genetic elements [2,4,15], able to spread among the bacterial community very rapidly [6,12]. Considering that 62.96% of the Hgresistant bacterial strains harbored large, potentially conjugative plasmids, we were concerned by the potential acquisition of multiple resistances by human pathogens through conjugation with indigenous bacteria.…”

Section: Discussionmentioning

confidence: 99%

Mercury Resistance in Bacterial Strains Isolated from Tailing Ponds in a Gold Mining Area Near El Callao (Bolívar State, Venezuela)

et al. 2007

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Abstract. Bacterial resistance to mercury (Hg) was investigated in strains isolated from Hg-contaminated tailing ponds located in the gold mining area of El Callao (Bolívar State, Venezuela). High frequencies of resistance were detected to both inorganic-Hg and organomercurials among these strains. A broad range of resistance levels was observed when determining minimal inhibitory concentrations of Hg 2+ . Some strains were able to grow in liquid medium containing 25 lM Hg 2+ , whereas others grew at 300 lM Hg 2+ . Of 190 Hg-resistant strains tested, 58.2% were additionally shown to be resistant to ampicillin (40 mg/L), 33.3% to chloramphenicol (30 mg/L), 24.9% to streptomycin (30 mg/L), 23.3% to tetracycline (30 mg/L), and 1.6% to kanamycin (30 mg/L). Furthermore, we found that 20% of the Hgresistant strains were simultaneously resistant to as many as four of these antibiotics, at the concentrations tested. The presence of large plasmids in 62.9% of 53 Hg-resistant strains screened prompted us to investigate the horizontal transfer of resistance determinants. Mating experiments were performed using Escherichia coli and Pseudomonas aeruginosa as recipient strains. The results obtained confirmed that indigenous Hg-resistant bacteria colonizing the tailing ponds can effectively transfer the phenotype to potentially pathogenic species.

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Section: Discussionmentioning

confidence: 99%

Mercury Resistance in Bacterial Strains Isolated from Tailing Ponds in a Gold Mining Area Near El Callao (Bolívar State, Venezuela)

et al. 2007

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“…In Gram-positive bacteria, the cad operon from Bacillus and Staphylococcus members has been well studied (Silver & Phung 1996). In both Grampositive and Gram-negative bacteria the ars operons from Escherichia coli (Mobley et al 1983;Saltikov & Olson 2002) and Staphylococcus strains (Ji & Silver 1992;Rosenstein et al 1992), and the mer systems from Escherichia coli (Nascimento & Chartone-Souza 2003) and Bacillus populations (Bogdanova et al 1998) have been well characterized. In addition, the cyanobacterial smt locus from Synechococcus PCC 7942 also contains a well-characterized heavy metal resistance system (Erbe et al 1995).…”

Section: Introductionmentioning

confidence: 99%

The isolation of heavy-metal resistant culturable bacteria and resistance determinants from a heavy-metal-contaminated site

et al. 2010

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In this study we performed a phylogenetic analysis of a culturable bacterial community isolated from heavymetal-contaminated soil from southwest Slovakia using 16S rRNA (16S rDNA) and heavy-metal resistance genes. The soil sample contained high concentrations of nickel (2,109 mg/kg), cobalt (355 mg/kg) and zinc (177 mg/kg), smaller concentrations of iron (35.75 mg/kg) and copper (32.2 mg/kg), and a trace amount of cadmium (<0.25 mg/kg). A total of 100 isolates were grown on rich (Nutrient agar No. 2) or minimal (soil-extract agar medium) medium. The isolates were identified by phylogenetic analysis using partial sequences of their 16S rRNA (16S rDNA) genes. Representatives of two broad taxonomic groups, Firmicutes and Proteobacteria, were found on rich medium, whereas four taxonomic groups, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, were represented on minimal medium. Forty-two isolates grown on rich medium were assigned to 20 bacterial species, while 58 bacteria grown on minimal medium belonged to 49 species. Twenty-three isolates carried czcA-and/or nccA-like heavy-metal-resistance determinants. The heavy-metalresistance genes of nine isolates were identified by phylogenetic analysis of their protein sequences.

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“…Mer operons have been identified on plasmids (Clark et al 1977;Griffin et al 1987;Summers and Silver 1972), on transposons (Misra et al 1984;Huang et al 1999), and in genomic DNA (Inoue et al 1991;Wang et al 1987). As with resistance to antibiotics and other heavy metals, resistance to Hg can be disseminated through populations of bacteria by natural processes (Bogdanova et al 1998). For the present study, we analyzed the Hg content of a waste sample collected from a West Virginia coal surface mining facility.…”

Section: Introductionmentioning

confidence: 99%

Continuation of Crosscutting Technology Development at Cast

Yoon¹

2012

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5Figure ES-2. Optimization of conditions for leaching Coal B with hydrochloric acid solutions (The selection of time/pH conditions in the dark green region should result in the removal of >30% of the sodium. Note also that a flag has been added to show the amount of sodium in the leach solution, 35% sodium removal, and the sodium content in the product ash). Coal DCoal D showed significantly greater sodium removal than Coal B for similar treatment conditions. The treatability of Coal B is demonstrated in Figures ES3 to ES5. . Coal D leach results for hydrochloric acid solutions (Greater than 75% of the sodium was removed using pH 3 acidic solutions at a 1-hour treatment time. The initial sodium, reported as sodium oxide in the ash, was 6.16 %. The removal of over one-half of the sodium can be achieved using conditions of pH 5, 0.5 hours). Recommended Future StudiesIt is recommended that future studies include, but not be limited to:• Investigation to determine if multiple leach solution contacts with new coal will allow recycle of the leach solution without detrimentally affecting the leachability of the coals and to produce a concentrated sodium bearing solution in order to limit the amount of leach solution that would have to be treated prior to water recycle or disposal.• Water cleanup will be required because of the relatively high sodium and chloride or sulfate content.• Evaluation of where and how the leachate could be introduced into the coal preparation treatment system. • Evaluation of the possible impact of pretreatment on the subsequent shipping and combustion processes.• The anticipated cost of the sodium cleansing treatment and subsequent water treatments. INTRODUCTION BackgroundThe US Department of Energy (DOE) Center for Advanced Separation Technologies (CAST), Great Northern Properties (GN), and the Montana Board Research and Commercialization Technology (MBRCT) are funding this project. The project is being administered and the research directed and conducted at CAMP. The intent of the project is to identify, and validate selected currently used (or previously studied) removal and sodium recovery treatment alternative(s) using laboratory bench-scale tests on four Montana coal samples. If the coals cannot be effectively treated by known techniques, alternative treatments will be developed. The evaluation of selected sodium removal technologies are presently underway and the following four stages are being and will be followed in future work: the successful removal of sodium from the coal so that the ash will content less than three percent, the rate at which the sodium ions are removed, characterization of the waste produced by sodium removal processing, and the overall economics of viable processes. Not part of the initial Project, but a necessary follow-up, will be the scale-up of the most appropriate sodium removal technology(s) in applications with companies using Clean Coal Technology to demonstrate sodium removal process or processes on a pilot scale. Objective and ApproachThe overall ob...

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Horizontal spread of mer operons among Gram-positive bacteria in natural environments

Cited by 74 publications

References 56 publications

Mercury Resistance in Bacterial Strains Isolated from Tailing Ponds in a Gold Mining Area Near El Callao (Bolívar State, Venezuela)

Mercury Resistance in Bacterial Strains Isolated from Tailing Ponds in a Gold Mining Area Near El Callao (Bolívar State, Venezuela)

The isolation of heavy-metal resistant culturable bacteria and resistance determinants from a heavy-metal-contaminated site

Continuation of Crosscutting Technology Development at Cast

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