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Hernández-Beltrán JCR, San Millán A, Fuentes-Hernández A, Peña-Miller R. Mathematical Models of Plasmid Population Dynamics. Front Microbiol 2021; 12:606396. [PMID: 34803935 PMCID: PMC8600371 DOI: 10.3389/fmicb.2021.606396] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/14/2021] [Indexed: 11/24/2022] Open
Abstract
With plasmid-mediated antibiotic resistance thriving and threatening to become a serious public health problem, it is paramount to increase our understanding of the forces that enable the spread and maintenance of drug resistance genes encoded in mobile genetic elements. The relevance of plasmids as vehicles for the dissemination of antibiotic resistance genes, in addition to the extensive use of plasmid-derived vectors for biotechnological and industrial purposes, has promoted the in-depth study of the molecular mechanisms controlling multiple aspects of a plasmids' life cycle. This body of experimental work has been paralleled by the development of a wealth of mathematical models aimed at understanding the interplay between transmission, replication, and segregation, as well as their consequences in the ecological and evolutionary dynamics of plasmid-bearing bacterial populations. In this review, we discuss theoretical models of plasmid dynamics that span from the molecular mechanisms of plasmid partition and copy-number control occurring at a cellular level, to their consequences in the population dynamics of complex microbial communities. We conclude by discussing future directions for this exciting research topic.
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Affiliation(s)
| | | | | | - Rafael Peña-Miller
- Center for Genomic Sciences, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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2
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Stecher B, Maier L, Hardt WD. 'Blooming' in the gut: how dysbiosis might contribute to pathogen evolution. Nat Rev Microbiol 2013; 11:277-84. [DOI: 10.1038/nrmicro2989] [Citation(s) in RCA: 236] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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3
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Chen J, Jin M, Qiu ZG, Guo C, Chen ZL, Shen ZQ, Wang XW, Li JW. A survey of drug resistance bla genes originating from synthetic plasmid vectors in six Chinese rivers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:13448-13454. [PMID: 23215020 DOI: 10.1021/es302760s] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Antibiotic resistance poses a significant challenge to human health and its rate continues to rise globally. While antibiotic-selectable synthetic plasmid vectors have proved invaluable tools of genetic engineering, this class of artificial recombinant DNA sequences with high expression of antibiotic resistance genes presents an unknown risk beyond the laboratory setting. Contamination of environmental microbes with synthetic plasmid vector-sourced antibiotic resistance genes may represent a yet unrecognized source of antibiotic resistance. In this study, PCR and real-time quantitative PCR were used to investigate the synthetic plasmid vector-originated ampicillin resistance gene, β-lactam antibiotic (blá), in microbes from six Chinese rivers with significant human interactions. Various levels of blá were detected in all six rivers, with the highest levels in the Pearl and Haihe rivers. To validate the blá pollution, environmental plasmids in the river samples were captured by the E. coli transformants from the community plasmid metagenome. The resultant plasmid library of 205 ampicillin-resistant E. coli (transformants) showed a blá-positive rate of 27.3% by PCR. Sequencing results confirmed the synthetic plasmid vector sources. In addition, results of the Kirby-Bauer disc-diffusion test reinforced the ampicillin-resistant functions of the environmental plasmids. The resistance spectrum of transformants from the Pearl and Haihe rivers, in particular, had expanded to the third- and fourth-generation of cephalosporin drugs, while that of other transformants mainly involved first- and second-generation cephalosporins. This study not only reveals environmental contamination of synthetic plasmid vector-sourced blá drug resistance genes in Chinese rivers, but also suggests that synthetic plasmid vectors may represent a source of antibiotic resistance in humans.
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Affiliation(s)
- Jian Chen
- College of Life Sciences, Sichuan University, Chengdu, Sichuan Province 610064, People's Republic of China
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4
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Melamed S, Lalush C, Elad T, Yagur‐Kroll S, Belkin S, Pedahzur R. A bacterial reporter panel for the detection and classification of antibiotic substances. Microb Biotechnol 2012; 5:536-48. [PMID: 22385678 PMCID: PMC3815330 DOI: 10.1111/j.1751-7915.2012.00333.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 01/25/2012] [Indexed: 12/05/2022] Open
Abstract
The ever-growing use of pharmaceutical compounds, including antibacterial substances, poses a substantial pollution load on the environment. Such compounds can compromise water quality, contaminate soils, livestock and crops, enhance resistance of microorganisms to antibiotic substances, and hamper human health. We report the construction of a novel panel of genetically engineered Escherichia coli reporter strains for the detection and classification of antibiotic substances. Each of these strains harbours a plasmid that carries a fusion of a selected gene promoter to bioluminescence (luxCDABE) reporter genes and an alternative tryptophan auxotrophy-based non-antibiotic selection system. The bioreporter panel was tested for sensitivity and responsiveness to diverse antibiotic substances by monitoring bioluminescence as a function of time and of antibiotic concentrations. All of the tested antibiotics were detected by the panel, which displayed different response patterns for each substance. These unique responses were analysed by several algorithms that enabled clustering the compounds according to their functional properties, and allowed the classification of unknown antibiotic substances with a high degree of accuracy and confidence.
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Affiliation(s)
- Sahar Melamed
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Chaim Lalush
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Tal Elad
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Sharon Yagur‐Kroll
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Shimshon Belkin
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Rami Pedahzur
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Environmental Sciences, Hadassah Academic College, Jerusalem, Israel
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5
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Khomenkov VG, Shevelev AB, Zhukov VG, Zagustina NA, Bezborodov AM, Popov VO. Organization of metabolic pathways and molecular-genetic mechanisms of xenobiotic degradation in microorganisms: A review. APPL BIOCHEM MICRO+ 2011. [DOI: 10.1134/s0003683808020014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Jones RA, Broder MW, Stotzky G. Effects of genetically engineered microorganisms on nitrogen transformations and nitrogen-transforming microbial populations in soil. Appl Environ Microbiol 2010; 57:3212-9. [PMID: 16348584 PMCID: PMC183950 DOI: 10.1128/aem.57.11.3212-3219.1991] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The principal concern about releasing genetically engineered microorganisms (GEMs) into the environment is their potential adverse effects on the environment, whether caused directly or indirectly by the GEMs. The effects of five GEMs on ammonification, nitrification, and denitrification in soil were studied. With the possible exception of a strain of Enterobacter cloacae carrying a plasmid, no consistent statistically or ecologically significant differences in effects on these processes or on the population dynamics of the microorganisms responsible for the processes were observed between soils inoculated with the GEMs or their homologous plasmidless hosts and those that were not inoculated. Increasing the concentration of montmorillonite in the soil enhanced the rate of nitrification, regardless of the inoculum, indicating that the perfusion technique used was sensitive enough to detect changes in nitrification rates when they occurred.
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Affiliation(s)
- R A Jones
- Laboratory of Microbial Ecology, Department of Biology, New York University, New York, New York 10003
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Wellington EM, Cresswell N, Saunders VA. Growth and survival of streptomycete inoculants and extent of plasmid transfer in sterile and nonsterile soil. Appl Environ Microbiol 2010; 56:1413-9. [PMID: 16348192 PMCID: PMC184420 DOI: 10.1128/aem.56.5.1413-1419.1990] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The growth and survival of strains of Streptomyces lividans and S. violaceolatus in sterile and nonsterile soil was investigated by using inoculated soil microcosms run as batch systems. It was evident that, after an initial short mycelial growth phase of 2 to 3 days, sporulation occurred and inoculants survived as spores. The transfer of a high-copy-number, self-transmissible plasmid, pIJ673, was detected by using intra- and interspecific crosses. The initial detection of transconjugants correlated with the development of the mycelial state of the inoculants (as confirmed by scanning electron microscopy) after 2 days of incubation. Subsequent spread of the plasmid was attributed to spread within existing mycelium followed by sporulation. In natural soil, inoculant numbers remained constant or declined, but plasmid transfer was readily detected.
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Affiliation(s)
- E M Wellington
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, and School of Natural Sciences, Liverpool Polytechnic, Liverpool L3 3AF, United Kingdom
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8
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Hölzel C, Harms K, Küchenhoff H, Kunz A, Müller C, Meyer K, Schwaiger K, Bauer J. Phenotypic and genotypic bacterial antimicrobial resistance in liquid pig manure is variously associated with contents of tetracyclines and sulfonamides. J Appl Microbiol 2010; 108:1642-56. [DOI: 10.1111/j.1365-2672.2009.04570.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Soda S, Otsuki H, Inoue D, Tsutsui H, Sei K, Ike M. Transfer of antibiotic multiresistant plasmid RP4 from escherichia coli to activated sludge bacteria. J Biosci Bioeng 2008; 106:292-6. [DOI: 10.1263/jbb.106.292] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 06/19/2008] [Indexed: 11/17/2022]
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10
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Polano M, Anselmi C, Leita L, Negro A, De Nobili M. Organic polyanions act as complexants of prion protein in soil. Biochem Biophys Res Commun 2008; 367:323-9. [DOI: 10.1016/j.bbrc.2007.12.143] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
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11
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The Construction and Monitoring of Genetically Tagged, Plasmid-Containing, Naphthalene-Degrading Strains in Soil. Microbiology (Reading) 2005. [DOI: 10.1007/s11021-005-0088-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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12
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Luijten ML, Weelink SA, Godschalk B, Langenhoff AA, Eekert MH, Schraa G, Stams AJ. Anaerobic reduction and oxidation of quinone moieties and the reduction of oxidized metals by halorespiring and related organisms. FEMS Microbiol Ecol 2004; 49:145-50. [DOI: 10.1016/j.femsec.2004.01.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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13
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Crawford DL. Development of recombinant Streptomyces for biotechnological and environmental uses. Biotechnol Adv 2004; 6:183-206. [PMID: 14541215 DOI: 10.1016/0734-9750(88)90004-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recombinant DNA techniques for manipulation of genes in Streptomyces are well developed, and currently there is a high level of activity among researchers interested in applying molecular cloning and protoplast fusion techniques to strain development within this commercially important group of bacteria. A number of efficient plasmid and phage vector systems are being used for the molecular cloning of genes, primarily those encoding antibiotic biosynthesis enzymes, but also for a variety of other bioactive proteins and enzymes of known or potential commercial value. In addition, cloning aimed at constructing specialized bioconversion strains for use in the production of chemicals from organic carbon substrates is underway in numerous laboratories. This review discusses the current status of research involving recombinant DNA technologies applied to biotechnological applications using Streptomyces. The topic of potential environmental uses of recombinant Streptomyces is also reviewed, as is the status of current research aimed at assessing the fate and effects of recombinant Streptomyces in the environment. Also summarized is recent research that has confirmed that genetic exchange occurs readily among Streptomyces in the soil environment and which has shown the potential for exchange between recombinant Streptomyces and native soil bacteria.
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Affiliation(s)
- D L Crawford
- Department of Bacteriology and Biochemistry, Institute for Molecular and Agricultural Genetic Engineering, University of Idaho, Moscow, Idaho 83843, USA
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14
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Hinnebusch BJ, Rosso ML, Schwan TG, Carniel E. High-frequency conjugative transfer of antibiotic resistance genes to Yersinia pestis in the flea midgut. Mol Microbiol 2002; 46:349-54. [PMID: 12406213 DOI: 10.1046/j.1365-2958.2002.03159.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The acquisition of foreign DNA by horizontal transfer from unrelated organisms is a major source of variation leading to new strains of bacterial pathogens. The extent to which this occurs varies widely, due in part to lifestyle factors that determine exposure to potential donors. Yersinia pestis, the plague bacillus, infects normally sterile sites in its mammalian host, but forms dense aggregates in the non-sterile digestive tract of its flea vector to produce a transmissible infection. Here we show that unrelated co-infecting bacteria in the flea midgut are readily incorporated into these aggregates, and that this close physical contact leads to high-frequency conjugative genetic exchange. Transfer of an antibiotic resistance plasmid from an Escherichia coli donor to Y. pestis occurred in the flea midgut at a frequency of 10-3 after only 3 days of co-infection, and after 4 weeks 95% of co-infected fleas contained an average of 103 antibiotic-resistant Y. pestis transconjugants. Thus, transit in its arthropod vector exposes Y. pestis to favourable conditions for efficient genetic exchange with microbial flora of the flea gut. Horizontal gene transfer in the flea may be the source of antibiotic-resistant Y. pestis strains recently isolated from plague patients in Madagascar.
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Affiliation(s)
- B Joseph Hinnebusch
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, Hamilton, MT 59840, USA.
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15
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. IHS, . PA, . SH. Use of Synthetic DNA as New Tracers for Tracing Groungwater Flow and Multiple Contaminants. ACTA ACUST UNITED AC 2001. [DOI: 10.3923/jas.2001.233.238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Hansen LH, Ferrari B, Sørensen AH, Veal D, Sørensen SJ. Detection of oxytetracycline production by Streptomyces rimosus in soil microcosms by combining whole-cell biosensors and flow cytometry. Appl Environ Microbiol 2001; 67:239-44. [PMID: 11133451 PMCID: PMC92555 DOI: 10.1128/aem.67.1.239-244.2001] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2000] [Accepted: 11/01/2000] [Indexed: 11/20/2022] Open
Abstract
Combining the high specificity of bacterial biosensors and the resolution power of fluorescence-activated cell sorting (FACS) provided qualitative detection of oxytetracycline production by Streptomyces rimosus in soil microcosms. A plasmid containing a transcriptional fusion between the tetR-regulated P(tet) promoter from Tn10 and a FACS-optimized gfp gene was constructed. When harbored by Escherichia coli, this plasmid produces large amounts of green fluorescent protein (GFP) in the presence of tetracycline. This tetracycline biosensor was used to detect the production of oxytetracycline by S. rimosus introduced into sterile soil. The tetracycline-induced GFP-producing biosensors were detected by FACS analysis, enabling the detection of oxytetracycline encounters by single biosensor cells. This approach can be used to study interactions between antibiotic producers and their target organisms in soil.
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Affiliation(s)
- L H Hansen
- Department of General Microbiology, University of Copenhagen, DK-1307 Copenhagen K, Denmark
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17
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Safe biotechnology 10: DNA content of biotechnological process waste. The Safety in Biotechnology Working Party of the European Federation of Biotechnology. Trends Biotechnol 2000; 18:141-6. [PMID: 10740259 DOI: 10.1016/s0167-7799(00)01424-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The adequacy of the existing treatment, disposal and recycling processes of waste streams from biotechnological laboratories and industrial processes, especially those using genetically modified microorganisms, have been repeatedly discussed. Here, we focus on the discussions linked to the DNA content of these wastes, the properties of extracellular (or 'naked') DNA and the ability to transfer genetic information between bacteria (e.g. antibiotic resistances) or into higher organisms.
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18
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Min M, Kawabata Z, Ishii N, Takata R, Furukawa K. Fate of a PCBS degrading recombinantpseudomonas putidaAC30(PMFB2) and its effect on the densities of microbes in marine microcosms contaminated with PCBS. ACTA ACUST UNITED AC 1998. [DOI: 10.1080/00207239808711185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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20
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Sikorski J, Graupner S, Lorenz MG, Wackernagel W. Natural genetic transformation of Pseudomonas stutzeri in a non-sterile soil. MICROBIOLOGY (READING, ENGLAND) 1998; 144 ( Pt 2):569-576. [PMID: 9493393 DOI: 10.1099/00221287-144-2-569] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Natural transformation of the soil bacterium Pseudomonas stutzeri JM300 in a non-sterile brown earth microcosm was studied. For this purpose, the microcosm was loaded with purified DNA (plasmid or chromosomal DNA, both containing a high-frequency-transformation marker, his+, of the P. stutzeri genome), the non-adsorbed DNA was washed out with soil extract and then the soil was charged with competent cells (his-1). Both chromosomal and plasmid transformants were found among the P. stutzeri cells recovered from the soil. The number of plasmid transformants increased in a linear fashion with the amount of DNA added [10-600 ng (0.7 g soil)-1]. The observed efficiency of transformation, the time course of transformant formation and the complete inhibition of transformation by DNase I, when added to the soil, were similar to that seen in optimized transformations in nutrient broth. Addition of cells as late as 3 d after loading the soil with plasmid DNA still yielded 3% of the initial transforming activity. This suggests that nucleases indigenous to the soil destroyed the transforming DNA, but at a rate allowing considerable DNA persistence. Transformants were also obtained when intact P. stutzeri cells were introduced into the soil to serve as plasmid DNA donors. Apparently, DNA was released from the cells, adsorbed to the soil material and subsequently taken up by recipient cells. The results indicate that competent cells of P. stutzeri were able to find access to and take up DNA bound on soil particles in the presence of micro-organisms and DNases indigenous to the soil.
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Affiliation(s)
- Johannes Sikorski
- Genetik, Fachbereich Biologie, Carl von Ossietzky Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany
| | - Stefan Graupner
- Genetik, Fachbereich Biologie, Carl von Ossietzky Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany
| | - Michael G Lorenz
- Genetik, Fachbereich Biologie, Carl von Ossietzky Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany
| | - Wilfried Wackernagel
- Genetik, Fachbereich Biologie, Carl von Ossietzky Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany
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21
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Yin X, Stotzky G. Gene transfer among bacteria in natural environments. ADVANCES IN APPLIED MICROBIOLOGY 1997; 45:153-212. [PMID: 9342828 DOI: 10.1016/s0065-2164(08)70263-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- X Yin
- SRA Technologies, Inc., Rockville, Maryland 20850, USA
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22
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DiGiovanni GD, Neilson JW, Pepper IL, Sinclair NA. Gene transfer of Alcaligenes eutrophus JMP134 plasmid pJP4 to indigenous soil recipients. Appl Environ Microbiol 1996; 62:2521-6. [PMID: 8779592 PMCID: PMC168035 DOI: 10.1128/aem.62.7.2521-2526.1996] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
This study evaluated the potential for gene transfer of a large catabolic plasmid from an introduced organism to indigenous soil recipients. The donor organism Alcaligenes eutrophus JMP134 contained the 80-kb plasmid pJP4, which contains genes that code for mercury resistance. Genes on this plasmid plus chromosomal genes also allow degradation of 2,4-dichloruphenoxyacetic acid (2,4-D). When JMP134 was inoculated into a nonsterile soil microcosm amended with 1,000 micrograms of 2,4-D g-1, significant (10(6) g of soil-1) populations of indigenous recipients or transconjugants arose. These transconjugants all contained an 80-kb plasmid similar in size to pJP4, and all degraded 2,4-D. In addition, all transconjugants were resistant to mercury and contained the tfdB gene of pJP4 as detected by PCR. No mercury-resistant, 2,4-D-degrading organisms with large plasmids or the tfdB gene were found in the 2,4-D-amended but uninoculated control microcosm. These data clearly show that the plasmid pJP4 was transferred to indigenous soil recipients. Even more striking is the fact that not only did the indigenous transconjugant population survive and proliferate but also enhanced rates of 2,4-D degradation occurred relative to microcosms in which no such gene transfer occurred. Overall, these data indicate that gene transfer from introduced organisms is an effective means of bioaugmentation and that survival of the introduced organism is not a prerequisite for biodegradation that utilizes introduced biodegradative genes.
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Affiliation(s)
- G D DiGiovanni
- Department of Soil, Water, and Environmental Science, University of Arizona, Tucson 85721, USA
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23
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Trevors JT. DNA in soil: adsorption, genetic transformation, molecular evolution and genetic microchip. Antonie Van Leeuwenhoek 1996; 70:1-10. [PMID: 8836436 DOI: 10.1007/bf00393564] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This review examines interactions between DNA and soil with an emphasis on the persistence and stability of DNA in soil. The role of DNA in genetic transformation in soil microorganisms will also be discussed. In addition, a postulated mechanism for stabilization and elongation/assembly of primitive genetic material and the role of soil particles, salt concentrations, temperature cycling and crystal formation is examined.
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Affiliation(s)
- J T Trevors
- Department of Environmental Biology, University of Guelph, Ontario, Canada.
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24
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Pukall R, Tschäpe H, Smalla K. Monitoring the spread of broad host and narrow host range plasmids in soil microcosms. FEMS Microbiol Ecol 1996. [DOI: 10.1111/j.1574-6941.1996.tb00304.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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25
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Abstract
Microbial biofilms are notably recalcitrant towards treatment with antibiotics, biocides or disinfectants that would adequately control the same organisms growing in planktonic mode. Much of this resistance has been attributed to an organisation of the biofilm cells within exopolymer matrices. Whilst such exopolymers are unlikely to hinder the diffusion and access of antimicrobial agents to the underlying cells, they will chemically quench reactive biocides such as chlorine and peroxygens, and bind highly charged antibiotics, such as tobramycin and gentamycin, thereby providing some protection to the more deep lying cells. Extracellular enzymes, bound within the glycocalyx and able to degrade the treatment agents, will further reduce the access of susceptible compounds. Diffusion limitation however, is unlikely to be the sole moderator of the resistance properties of microbial biofilms. In addition, gradients of oxygen and nutrients established across the biofilm community will cause growth rates to be much reduced at points remoted from the accessible nutrient. Slow growth rates, and the associated induction of stringent responses further contribute towards this resistance. Finally, there have been recent demonstrations that attachment of microorganisms to surfaces promotes the expression of genes that are not normally expressed in planktonic culture. Whether or not the expression of such genes alters the phenotype in a manner which alters the response of the cells to antimicrobial agents remains to be demonstrated.
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Affiliation(s)
- I Foley
- a Department of Pharmacy , University of Manchester , Oxford Road , Manchester , M13 9PL , UK
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26
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Top EM, Rore H, Collard JM, Gellens V, Slobodkina G, Verstraete W, Mergeay M. Retromobilization of heavy metal resistance genes in unpolluted and heavy metal polluted soil. FEMS Microbiol Ecol 1995. [DOI: 10.1111/j.1574-6941.1995.tb00176.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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27
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Doyle JD, Stotzky G, McClung G, Hendricks CW. Effects of genetically engineered microorganisms on microbial populations and processes in natural habitats. ADVANCES IN APPLIED MICROBIOLOGY 1995; 40:237-87. [PMID: 7604738 DOI: 10.1016/s0065-2164(08)70366-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J D Doyle
- ManTech Environmental Technology, Inc., Corvallis, Oregon 97333, USA
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28
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Neilson JW, Josephson KL, Pepper IL, Arnold RB, Di Giovanni GD, Sinclair NA. Frequency of horizontal gene transfer of a large catabolic plasmid (pJP4) in soil. Appl Environ Microbiol 1994; 60:4053-8. [PMID: 7993092 PMCID: PMC201935 DOI: 10.1128/aem.60.11.4053-4058.1994] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Limited work has been done to assess the bioremediation potential of transfer of plasmid-borne degradative genes from introduced to indigenous organisms in the environment. Here we demonstrate the transfer by conjugation of the catabolic plasmid pJP4, using a model system with donor and recipient organisms. The donor organism was Alcaligenes eutrophus JMP134 and the recipient organism was Variovorax paradoxus isolated from a toxic waste site. Plasmid pJP4 contains genes for mercury resistance and 2,4-dichlorophenoxyacetic (2,4-D) acid degradation. A transfer frequency of approximately 1/10(3) donor and recipient cells (parent cells) was observed on solid agar media, decreasing to 1/10(5) parent cells in sterile soil and finally 1/10(6) parent cells in 2,4-D-amended, nonsterile soil. Presumptive transconjugants were confirmed to be resistant to Hg, to be capable of degrading 2,4-D, and to contain a plasmid of size comparable to that of pJP4. In addition, we confirmed the transfer through PCR amplifications of the tfdB gene. Although transfer of pJP4 did occur at a high frequency in pure culture, the rate was significantly decreased by the introduction of abiotic (sterile soil) and biotic (nonsterile soil) stresses. An evaluation of the data from this model system implies that the reliance on plasmid transfer from a donor organism as a remediative strategy has limited potential.
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Affiliation(s)
- J W Neilson
- Department of Soil and Water Science, University of Arizona, Tucson 85721
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29
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Lorenz MG, Wackernagel W. Bacterial gene transfer by natural genetic transformation in the environment. Microbiol Rev 1994; 58:563-602. [PMID: 7968924 PMCID: PMC372978 DOI: 10.1128/mr.58.3.563-602.1994] [Citation(s) in RCA: 462] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Natural genetic transformation is the active uptake of free DNA by bacterial cells and the heritable incorporation of its genetic information. Since the famous discovery of transformation in Streptococcus pneumoniae by Griffith in 1928 and the demonstration of DNA as the transforming principle by Avery and coworkers in 1944, cellular processes involved in transformation have been studied extensively by in vitro experimentation with a few transformable species. Only more recently has it been considered that transformation may be a powerful mechanism of horizontal gene transfer in natural bacterial populations. In this review the current understanding of the biology of transformation is summarized to provide the platform on which aspects of bacterial transformation in water, soil, and sediments and the habitat of pathogens are discussed. Direct and indirect evidence for gene transfer routes by transformation within species and between different species will be presented, along with data suggesting that plasmids as well as chromosomal DNA are subject to genetic exchange via transformation. Experiments exploring the prerequisites for transformation in the environment, including the production and persistence of free DNA and factors important for the uptake of DNA by cells, will be compiled, as well as possible natural barriers to transformation. The efficiency of gene transfer by transformation in bacterial habitats is possibly genetically adjusted to submaximal levels. The fact that natural transformation has been detected among bacteria from all trophic and taxonomic groups including archaebacteria suggests that transformability evolved early in phylogeny. Probable functions of DNA uptake other than gene acquisition will be discussed. The body of information presently available suggests that transformation has a great impact on bacterial population dynamics as well as on bacterial evolution and speciation.
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Affiliation(s)
- M G Lorenz
- Genetik, Fachbereich Biologie, Carl-von-Ossietzky Universität Oldenburg, Germany
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30
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Kellenberger E. Genetic ecology: a new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations. EXPERIENTIA 1994; 50:429-37. [PMID: 8194578 DOI: 10.1007/bf01920741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
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Affiliation(s)
- E Kellenberger
- Institut de Génétique et de Biologie microbienne, Université de Lausanne, Switzerland
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31
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Smets BF, Rittmann BE, Stahl DA. The specific growth rate of Pseudomonas putida PAW1 influences the conjugal transfer rate of the TOL plasmid. Appl Environ Microbiol 1993; 59:3430-7. [PMID: 8250565 PMCID: PMC182470 DOI: 10.1128/aem.59.10.3430-3437.1993] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The kinetics of the conjugal transfer of a TOL plasmid were investigated by using Pseudomonas putida PAW1 as the donor strain and P. aeruginosa PAO 1162 as the recipient strain. Short-term batch mating experiments were performed in a nonselective medium, while the evolution of the different cell types was determined by selective plating techniques. The experimental data were analyzed by using a mass action model that describes plasmid transfer kinetics. This method allowed analysis of the mating experiments by a single intrinsic kinetic parameter for conjugal plasmid transfer. Further results indicated that the specific growth rate of the donor strain antecedent to the mating experiment had a strong impact on the measured intrinsic plasmid transfer rate coefficient, which ranged from 1 x 10(-14) to 5 x 10(-13) ml per cell per min. Preliminary analysis suggested that the transfer rates of the TOL plasmid are large enough to maintain the TOL plasmid in a dense microbial community without selective pressures.
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Affiliation(s)
- B F Smets
- Department of Civil Engineering, University of Illinois, Urbana 61801
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32
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Goodman AE, Hild E, Marshall KC, Hermansson M. Conjugative Plasmid Transfer between Bacteria under Simulated Marine Oligotrophic Conditions. Appl Environ Microbiol 1993; 59:1035-40. [PMID: 16348904 PMCID: PMC202234 DOI: 10.1128/aem.59.4.1035-1040.1993] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Marine
Vibrio
S14 strains and an
Escherichia coli
strain were starved in artificial seawater (NSS) with no added carbon, nitrogen, or phosphorus. The broad-host-range plasmid RP1 was transferred between the starving S14 strains and also from the
E. coli
donor to the S14 recipient under oligotrophic conditions, in which mixtures of donor and recipient cells were held on Nuclepore filters either floated on NSS or held such that NSS flowed through the filter. Transconjugants were obtained from S14 donors and recipients starved for at least 15 days before being mixed together for conjugation, whereas transconjugants were recovered from the
E. coli
donor and S14 recipient for up to 3 days of prestarvation, but not after 5 days. Transconjugants were obtained when there were as few as about 10
5
and 10
4
cells of starving S14 donors and recipients, respectively, per ml held on the filters. Starved donor and recipient mixtures incubated at 4 or 26°C, as well as those allowed to mate for 2, 5, or 24 h, all yielded numbers of transconjugants which were not significantly (
P
> 0.05) different.
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Affiliation(s)
- A E Goodman
- School of Microbiology and Immunology, The University of New South Wales, P.O. Box 1, Kensington, 2033, NSW, Australia
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33
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34
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Stotzky G, Broder M, Doyle J, Jones R. Selected Methods for the Detection and Assessment of Ecological Effects Resulting from the Release of Genetically Engineered Microorganisms to the Terrestrial Environment. ADVANCES IN APPLIED MICROBIOLOGY 1993. [DOI: 10.1016/s0065-2164(08)70214-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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35
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van der Meer JR, de Vos WM, Harayama S, Zehnder AJ. Molecular mechanisms of genetic adaptation to xenobiotic compounds. Microbiol Rev 1992; 56:677-94. [PMID: 1480115 PMCID: PMC372894 DOI: 10.1128/mr.56.4.677-694.1992] [Citation(s) in RCA: 226] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Microorganisms in the environment can often adapt to use xenobiotic chemicals as novel growth and energy substrates. Specialized enzyme systems and metabolic pathways for the degradation of man-made compounds such as chlorobiphenyls and chlorobenzenes have been found in microorganisms isolated from geographically separated areas of the world. The genetic characterization of an increasing number of aerobic pathways for degradation of (substituted) aromatic compounds in different bacteria has made it possible to compare the similarities in genetic organization and in sequence which exist between genes and proteins of these specialized catabolic routes and more common pathways. These data suggest that discrete modules containing clusters of genes have been combined in different ways in the various catabolic pathways. Sequence information further suggests divergence of catabolic genes coding for specialized enzymes in the degradation of xenobiotic chemicals. An important question will be to find whether these specialized enzymes evolved from more common isozymes only after the introduction of xenobiotic chemicals into the environment. Evidence is presented that a range of genetic mechanisms, such as gene transfer, mutational drift, and genetic recombination and transposition, can accelerate the evolution of catabolic pathways in bacteria. However, there is virtually no information concerning the rates at which these mechanisms are operating in bacteria living in nature and the response of such rates to the presence of potential (xenobiotic) substrates. Quantitative data on the genetic processes in the natural environment and on the effect of environmental parameters on the rate of evolution are needed.
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Affiliation(s)
- J R van der Meer
- Department of Microbiology, Wageningen Agricultural University, The Netherlands
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36
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Romanowski G, Lorenz MG, Sayler G, Wackernagel W. Persistence of Free Plasmid DNA in Soil Monitored by Various Methods, Including a Transformation Assay. Appl Environ Microbiol 1992; 58:3012-9. [PMID: 16348772 PMCID: PMC183041 DOI: 10.1128/aem.58.9.3012-3019.1992] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The persistence and stability of free plasmid pUC8-ISP DNA introduced into 10-g samples of various soils and kept at 23°C were monitored over a period of 60 days. The soils were sampled at a plant science farm and included a loamy sand soil (no. 1), a clay soil (no. 2), and a silty clay soil (no. 3). Four different methods allowed monitoring of (i) the production of acid-soluble radioactive material from [
3
H]thymidine-labeled plasmid DNA, (ii) the decrease of hybridizing nucleotide sequences in slot blot analysis, (iii) the loss of plasmid integrity measured by Southern hybridization, and (iv) the decay of the biological activity as determined by transformation of Ca
2+
-treated
Escherichia coli
cells with the DNA extracted from soil. Acid-soluble material was not produced within the first 24 h but then increased to 45% (soil no. 1), 27% (soil no. 2), and 77% (soil no. 3) until the end of incubation. A quite parallel loss of material giving a slot blot hybridization signal was observed. Southern hybridization indicated that after 1 h in the soils, plasmid DNA was mostly in the form of circular and full-length linear molecules but that, depending on the soil type, after 2 to 5 days full-length plasmid molecules were hardly detectable. The transforming activity of plasmid DNA reextracted from the soils followed inactivation curves over 2 to 4 orders of magnitude and dropped below the detection limit after 10 days. The inactivation was slower in soil no. 2 (28.2-h half-life time of the transforming activity of a plasmid molecule) than in soils no. 3 (15.1 h) and no. 1 (9.1 h). The studies provide data on the persistence of free DNA molecules in natural bacterial soil habitats. The data suggest that plasmid DNA may persist long enough to be available for uptake by competent recipient cells in situ.
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Affiliation(s)
- G Romanowski
- Genetik, Fachbereich Biologie, Universität Oldenburg, Postfach 2503, W-2900 Oldenburg, Germany, and Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37932
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37
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Khanna M, Stotzky G. Transformation of Bacillus subtilis by DNA bound on montmorillonite and effect of DNase on the transforming ability of bound DNA. Appl Environ Microbiol 1992; 58:1930-9. [PMID: 1622268 PMCID: PMC195706 DOI: 10.1128/aem.58.6.1930-1939.1992] [Citation(s) in RCA: 208] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The equilibrium adsorption and binding of DNA from Bacillus subtilis on the clay mineral montmorillonite, the ability of bound DNA to transform competent cells, and the resistance of bound DNA to degradation by DNase I are reported. Maximum adsorption of DNA on the clay occurred after 90 min of contact and was followed by a plateau. Adsorption was pH dependent and was greatest at pH 1.0 (19.9 micrograms of DNA mg of clay-1) and least at pH 9.0 (10.7 micrograms of DNA mg of clay-1). The transformation frequency increased as the pH at which the clay-DNA complexes were prepared increased, and there was no transformation by clay-DNA complexes prepared at pH 1. After extensive washing with deionized distilled water (pH 5.5) or DNA buffer (pH 7.5), 21 and 28%, respectively, of the DNA remained bound. Bound DNA was capable of transforming competent cells (as was the desorbed DNA), indicating that adsorption, desorption, and binding did not alter the transforming ability of the DNA. Maximum transformation by bound DNA occurred at 37 degrees C (the other temperatures evaluated were 0, 25, and 45 degrees C). DNA bound on montmorillonite was protected against degradation by DNase, supporting the concept that "cryptic genes" may persist in the environment when bound on particulates. The concentration of DNase required to inhibit transformation by bound DNA was higher than that required to inhibit transformation by comparable amounts of free DNA, and considerably more bound than free DNase was required to inhibit transformation by the same amount of free DNA. Similarly, when DNA and DNase were bound on the same or separate samples of montmorillonite, the bound DNA was protected from the activity of DNase.
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Affiliation(s)
- M Khanna
- Department of Biology, New York University, New York 10003
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38
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Lorenz MG, Reipschläger K, Wackernagel W. Plasmid transformation of naturally competent Acinetobacter calcoaceticus in non-sterile soil extract and groundwater. Arch Microbiol 1992; 157:355-60. [PMID: 1590708 DOI: 10.1007/bf00248681] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The natural transformation of Acinetobacter calcoaceticus BD413 (trpE27) was characterized with respect to features that might be important for a possible gene transfer by extracellular DNA in natural environments. Transformation of competent cells with chromosomal DNA (marker trp+) occurred in aqueous solutions of single divalent cations. Uptake of DNA into the DNase I-resistant state but not the binding of DNA to cells was strongly stimulated by divalent cations. An increase of transformation of nearly 3 orders of magnitude was obtained as a response to the presence of 0.25 mM Ca2+. With CaCl2 solutions the transformation frequencies approached the highest values obtained under standard broth conditions, followed by MnCl2 and MgCl2. It is concluded that transformation requires divalent cations. DNA competition experiments showed that A. calcoaceticus does not discriminate between homologous and heterologous DNA. Furthermore, circular plasmid DNA competed with chromosomal DNA fragments and vice versa. The equally efficient transformation with plasmid pKT210 isolated from A. calcoaceticus or Escherichia coli indicated absence of DNA restriction in transformation. High efficiency plasmid transformation was obtained in samples of non-sterile natural groundwater and in non-sterile extracts of fresh and air-dried soil. Heat-treatment (10 min, 80 degrees C) of the non-sterile liquid samples increased transformation only in the dried soil extract, probably by inactivation of DNases. The results presented suggest that competent cells of A. calcoaceticus can take up free high molecular weight DNA including plasmids of any source in natural environments such as soil, sediment or groundwater.
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Affiliation(s)
- M G Lorenz
- Genetik, Fachbereich Biologie, Universität Oldenburg, Federal Republic of Germany
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39
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Wagner-Döbler I, Pipke R, Timmis KN, Dwyer DF. Evaluation of aquatic sediment microcosms and their use in assessing possible effects of introduced microorganisms on ecosystem parameters. Appl Environ Microbiol 1992; 58:1249-58. [PMID: 1599244 PMCID: PMC195583 DOI: 10.1128/aem.58.4.1249-1258.1992] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In this paper we describe a sediment microcosm system consisting of 20 undisturbed, layered sediment cores with overlying site water which are incubated under identical conditions of temperature, light, stirring rate of overlying water, and water exchange rate. Ecosystem parameters (nutrient level, photosynthetic potential, community structure of heterotrophic bacteria, thymidine incorporation rate, and oxygen microgradients) of the laboratory microcosms and the source ecosystem were compared and shown to be indistinguishable for the first 2 weeks. In weeks 3 and 4, small differences were detectable in the nutrient level, community structure of heterotrophic bacteria, and thymidine incorporation rate. However, the photosynthetic potential, depth profiles of heterotrophic bacterial community structure, and oxygen microgradients were maintained throughout the incubation period and did not differ between laboratory microcosms and the source ecosystem. The microcosm system described here would thus appear to be a valid model of aquatic sediments for up to 4 weeks; the actual period would depend on the sediment source and incubation temperature. The validated systems were used with Rhine river sediment to assess possible effects on ecosystem parameters of Pseudomonas sp. strain B13 FR1(pFRC20P), a genetically engineered microorganism (GEM) that had been constructed to degrade mixtures of halo- and alkylbenzoates and -phenols. The GEM survived in the surface sediment at densities of 5 x 10(4) to 5 x 10(5)/g (dry weight) for 4 weeks and degraded added chloro- and methylaromatics. The GEM did not measurably influence ecosystem parameters such as photosynthesis, densities of selected heterotrophic bacteria, thymidine incorporation rate, and oxygen microgradients. Thus, the microcosm system described here would seem to be useful for the study of the ecology of biodegradation and the fate and effect of microorganisms introduced into the environment.
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Affiliation(s)
- I Wagner-Döbler
- Molecular Microbial Ecology Group, Department of Microbiology, National Research Center for Biotechnology, Braunschweig, Germany
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40
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Doucet-Populaire F, Trieu-Cuot P, Andremont A, Courvalin P. Conjugal transfer of plasmid DNA from Enterococcus faecalis to Escherichia coli in digestive tracts of gnotobiotic mice. Antimicrob Agents Chemother 1992; 36:502-4. [PMID: 1605622 PMCID: PMC188470 DOI: 10.1128/aac.36.2.502] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have studied the transfer of the conjugative shuttle plasmid pAT191, which confers resistance to kanamycin, from Enterococcus faecalis to Escherichia coli in the digestive tracts of six gnotobiotic mice. Colonies of E. coli resistant to kanamycin were isolated from the feces of two mice, respectively, on days 25 and 35 after the beginning of the experiment and never thereafter. The transfer frequency of pAT191, expressed as the number of transconjugants per donor cell isolated from intestines of sacrificed mice, was 3 x 10(-9). These results indicate that conjugation is a mechanism that could account for the resistance gene flux from gram-positive to gram-negative bacteria observed in nature.
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Affiliation(s)
- F Doucet-Populaire
- Laboratoire d'Ecologie Microbienne, Institut Gustave-Roussy, Villejuif, France
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41
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42
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Hussey C. Recombinant plasmids. SAFETY IN INDUSTRIAL MICROBIOLOGY AND BIOTECHNOLOGY 1992. [PMCID: PMC7155667 DOI: 10.1016/b978-0-7506-1105-3.50010-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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43
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Amici A, Bazzicalupo M, Gallori E, Rollo F. Monitoring a genetically engineered bacterium in a freshwater environment by rapid enzymatic amplification of a synthetic DNA ?number-plate? Appl Microbiol Biotechnol 1991; 36:222-7. [PMID: 1369367 DOI: 10.1007/bf00164424] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In order to set up a sensitive and reliable detection method to monitor environmentally released genetically engineered microorganisms (GEMs) a 72-bp, double-stranded DNA fragment has been built by annealing and ligating four synthetic oligonucleotides. Binding sites for two 20-mer oligonucleotides are situated inside the DNA fragment, flanking the centre. Into the central part of the construction a 30-nucleotide identification sequence has been fitted. Thanks to the presence of the two oligonucleotide binding sites, the synthetic construction ("number-plate") can be submitted to enzymatic amplification using the polymerase chain reaction (PCR), thus enabling the identification system to take advantage of the outstanding sensitivity of this technique. When released into a freshwater microcosm, cells of Pseudomonas putida carrying a "number-plated" chromosome could be easily and rapidly detected merely by submitting boiled cell sediments to PCR amplification.
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Affiliation(s)
- A Amici
- Dipartimento di Biologia Molecolare Cellulare e Animale, Università di Camerino, Italy
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44
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Viljanen P, Boratynski J. The susceptibility of conjugative resistance transfer in gram-negative bacteria to physicochemical and biochemical agents. FEMS Microbiol Rev 1991; 8:43-54. [PMID: 1931138 DOI: 10.1111/j.1574-6968.1991.tb04956.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Over thirty years of studies have established that conjugative transfer of plasmid-encoded resistance to drugs and heavy metals can take place at high frequency between various organisms under laboratory conditions. The detected transfer frequencies in soil, in aquatic environments, and in the urogenital and respiratory tracts of healthy animals and man have generally been low. However, the conversion of bacteria from susceptible to resistant to antibiotics has been observed often during antimicrobial therapy. This has formed a challenge for the antibacterial treatment of pathogenic bacteria and called for the evaluation of the extent of conjugative transfer in various environments. Several biochemical and physicochemical factors inhibit conjugation, show preferential toxicity against plasmid-bearing cells, or stimulate plasmid curing. These factors include various agents such as detergents, anesthetics, mutagens and antibiotics which affect membrane potential, membrane permeability, protein synthesis and the processing of DNA. The application of the data on these agents, summarized in this review, might be helpful in preventing drug multi-resistance from spreading. Also these data might be valuable in studies which use conjugation as a tool or which treat the molecular mechanisms involved in conjugation.
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Affiliation(s)
- P Viljanen
- Miyazaki University, Faculty of Agriculture, Japan
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45
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Fulthorpe RR, Wyndham RC. Transfer and Expression of the Catabolic Plasmid pBRC60 in Wild Bacterial Recipients in a Freshwater Ecosystem. Appl Environ Microbiol 1991; 57:1546-53. [PMID: 16348493 PMCID: PMC182983 DOI: 10.1128/aem.57.5.1546-1553.1991] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
3-Chlorobenzoate (3Cba)-degrading bacteria were isolated from the waters and sediments of flowthrough mesocosms dosed with various concentrations of 3Cba and inoculated with a 3Cba-degrading
Alcaligenes
sp., strain BR60. Bacteria capable of 3Cba degradation which were distinct from BR60 were isolated. They carried pBRC60, a plasmid introduced with
Alcaligenes
sp. strain BR60 that carries a transposable element (Tn
5271
) encoding 3Cba degradation. The isolates expressed these genes in different ways. The majority of pBRC60 recipients were motile, yellow-pigmented, gram-negative rods related to the group III pseudomonads and to BR60 by substrate utilization pattern. They were capable of complete 3Cba degradation at both millimolar and micromolar concentrations. Two isolates,
Pseudomonas fluorescens
PR24B(pBRC60) and
Pseudomonas
sp. strain PR120(pBRC60), are more distantly related to BR60 and both produced chlorocatechol when exposed to 3Cba at millimolar concentrations in the presence of yeast extract. These species showed poor growth in liquid 3Cba minimal medium but could degrade 3Cba in continuous cultures dosed with micromolar levels of the chemical. Laboratory matings confirm that pBRC60 can transfer from BR60 to species in both the beta and gamma subgroups of the proteobacteria and that 3Cba gene expression is variable between species. Selection pressures acting on pBRC60 recipients are discussed.
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Affiliation(s)
- R R Fulthorpe
- Carleton University, Ottawa, Ontario, Canada K1S 5B6
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46
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Bogosian G, Kane JF. Fate of recombinant Escherichia coli K-12 strains in the environment. ADVANCES IN APPLIED MICROBIOLOGY 1991; 36:87-131. [PMID: 1877384 DOI: 10.1016/s0065-2164(08)70452-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- G Bogosian
- Animal Sciences Division, Monsanto Company, St. Louis, Missouri 63198
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47
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Stotzky G, Zeph LR, Devanas MA. Factors affecting the transfer of genetic information among microorganisms in soil. BIOTECHNOLOGY (READING, MASS.) 1991; 15:95-122. [PMID: 2009389 DOI: 10.1016/b978-0-409-90199-3.50012-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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48
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Top E, Mergeay M, Springael D, Verstraete W. Gene escape model: transfer of heavy metal resistance genes from Escherichia coli to Alcaligenes eutrophus on agar plates and in soil samples. Appl Environ Microbiol 1990; 56:2471-9. [PMID: 2206101 PMCID: PMC184750 DOI: 10.1128/aem.56.8.2471-2479.1990] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Conjugal transfer from Escherichia coli to Alcaligenes eutrophus of the A. eutrophus genes coding for plasmid-borne resistance to cadmium, cobalt, and zinc (czc genes) was investigated on agar plates and in soil samples. This czc fragment is not expressed in the donor strain, E. coli, but it is expressed in the recipient strain, A. eutrophus. Hence, expression of heavy metal resistance by cells plated on a medium containing heavy metals represents escape of the czc genes. The two plasmids into which this DNA fragment has been cloned previously and which were used in these experiments are the nonconjugative, mobilizable plasmid pDN705 and the nonconjugative, nonmobilizable plasmid pMOL149. In plate matings at 28 to 30 degrees C, the direct mobilization of pDN705 occurred at a frequency of 2.4 x 10(-2) per recipient, and the mobilization of the same plasmid by means of the IncP1 conjugative plasmids RP4 or pULB113 (present either in a third cell [triparental cross] or in the recipient strain itself [retromobilization]) occurred at average frequencies of 8 x 10(-4) and 2 x 10(-5) per recipient, respectively. The czc genes cloned into the Tra- Mob- plasmid pMOL149 were transferred at a frequency of 10(-7) to 10(-8) and only by means of plasmid pULB113. The direct mobilization of pDN705 was further investigated in sandy, sandy-loam, and clay soils. In sterile soils, transfer frequencies at 20 degrees C were highest in the sandy-loam soil (10(-5) per recipient) and were enhanced in all soils by the addition of easily metabolizable nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Top
- Laboratory of Microbial Ecology, Faculty of Agricultural Sciences, State University of Ghent, Belgium
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Herron PR, Wellington EM. New Method for Extraction of Streptomycete Spores from Soil and Application to the Study of Lysogeny in Sterile Amended and Nonsterile Soil. Appl Environ Microbiol 1990; 56:1406-12. [PMID: 16348191 PMCID: PMC184419 DOI: 10.1128/aem.56.5.1406-1412.1990] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new method for the isolation and enumeration of streptomycete spores from soil was developed. This method makes use of a cation-exchange resin to disperse soil particles. It allowed the detection of 10 spores in 100 g of sterile soil, while ca. 10
3
could be accurately enumerated in 100 g. This method was applied to studying the fate of a marked actinophage in soil. In sterile amended and nonsterile soil, relatively high numbers of actinophages were only found during the first few days of the experiment when the host streptomycete was in the mycelial form. Later, after sporulation, lysogens could be detected in sterile amended soil and could still be found 60 days after inoculation. Although no lysogens were found in nonsterile soil, the introduced phage could still be detected in the free state after 60 days, albeit at a low titer.
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Affiliation(s)
- P R Herron
- Department of Biological Sciences, University of Warwick, Coventry, West Midlands CV4 7AL, United Kingdom
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Stotzky G, Devanas MA, Zeph LR. Methods for studying bacterial gene transfer in soil by conjugation and transduction. ADVANCES IN APPLIED MICROBIOLOGY 1990; 35:57-169. [PMID: 2205084 DOI: 10.1016/s0065-2164(08)70243-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- G Stotzky
- Department of Biology, New York University, New York 10003
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