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Horizontal gene transfer between bacteria

Published online by Cambridge University Press:  26 October 2007

Holger Heuer  and
Kornelia Smalla
Holger Heuer
Affiliation:
Federal Biological Research Centre for Agriculture and Forestry (BBA), Braunschweig, Germany
Kornelia Smalla
Affiliation:
Federal Biological Research Centre for Agriculture and Forestry (BBA), Braunschweig, Germany

Abstract

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Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

Keywords

horizontal or lateral gene transfermobile genetic elementhorizontal gene poolgenome flexibility
Type
Research Article
Information
Environmental Biosafety Research , Volume 6 , Issue 1-2: Thematic Issue on Horizontal Gene Transfer , January 2007 , pp. 3 - 13
Copyright
© ISBR, EDP Sciences, 2007

References

Adamczyk, M, Jagura-Burdzy G (2003) Spread and survival of promiscuous IncP-1 plasmids. Acta Biochim. Pol. 50: 425–453
Arnold, DL, Pitman, A, Jackson, RW (2003) Pathogenicity and other genomic islands in plant pathogenic bacteria. Mol. Plant Pathol. 4: 407–420 CrossRef
Ashelford, KE, Day, MJ, Fry, JC (2003) Elevated abundance of bacteriophage infecting bacteria in soil. Appl. Environ. Microbiol. 69: 285–289 CrossRef
Bale, MJ, Fry, JC, Day, MJ (1988) Novel method for studying plasmid transfer in undisturbed river epilithon. Appl. Environ. Microbiol. 54: 2756–2758
Berg, OG, Kurland, CG (2002) Evolution of microbial genomes: Sequence acquisition and loss. Mol. Biol. Evol. 19: 2265–2276 CrossRef
Berka, RM, Hahn, J, Albano, M, Draskovic, I, Persuh, M, Cui, X, Sloma, A, Widner, W, Dubnau, D (2002) Microarray analysis of the Bacillus subtilis K-state: genome-wide expression changes dependent on ComK. Mol. Microbiol. 43: 1331–1345 CrossRef
Blum, SEA, Lorenz, MG, Wackernagel, W (1997) Mechanisms of retarded DNA degradation and prokaryotic origin of DNase in nonsterile soils. Syst. Appl. Microbiol. 20: 513–521 CrossRef
Boon, N, Goris, J, De Vos, P, Verstraete, W, Top, EM (2001) Genetic diversity among 3-chloroaniline- and aniline-degrading strains of the Comamonadaceae. Appl. Environ. Microbiol. 67: 1107–1115 CrossRef
Brüssow, H, Canchaya, C, Hardt, W (2004) Phages and the evolution of bacterial pathogens: from genomic rearrangements to lysogenic conversion. Microbiol. Mol. Biol. Rev. 68: 560–602 CrossRef
Brzuszkiewicz, E, Brüggemann, H, Liesegang, H, Emmerth, M, Ölschläger, T, Nagy, G, Albermann, K, Wagner, C, Buchrieser, C, Emody, L, Gottschalk, G, Hacker, J, Dobrindt, U (2006) How to become a uropathogen: comparative genomic analysis of extraintestinal pathogenic Escherichia coli strains. PNAS 103: 12879–12884 CrossRef
Burrus, V, Waldor, MK (2004) Shaping bacterial genomes with integrative and conjugative elements. Res. Microbiol. 155: 376–386 CrossRef
Canchaya, C, Proux, C, Fournous, G, Bruttin, A, Brüssow, H (2003) Prophage genomics. Microbiol. Mol. Biol. Rev. 67: 238–276 CrossRef
Cérémonie, H, Buret, F, Simonet, P, Vogel, TM (2004) Isolation of lightning-competent soil bacteria. Appl. Environ. Microbiol. 70: 6342–6346 CrossRef
Cérémonie, H, Buret, F, Simonet, P, Vogel, TM (2006) Natural electrotransformation of lightning-competent Pseudomonas sp. strain N3 in artificial soil microcosms. Appl. Environ. Microbiol. 72: 2385–2389 CrossRef
Chen, I, Dubnau, D (2004) DNA uptake during bacterial transformation. Nature Rev. Microbiol. 2: 241–249 CrossRef
Costa, R, Götz, M, Mrotzek, N, Lottmann, J, Berg, G, Smalla, K (2006a) Effect of site and plant species on rhizosphere community structure as revealed by molecular analysis of different microbial guilds. FEMS Microbiol. Ecol. 56: 236–249 CrossRef
Costa, R, Salles, JF, Berg, G, Smalla, K (2006b) Cultivation-independent analysis of Pseudomonas species in soil and in the rhizosphere of field-grown Verticillium dahliae host plants. Environ. Microbiol. 8: 2136–2149 CrossRef
Dahlberg, C, Chao, L (2003) Amelioration of the cost of conjugative plasmid carriage in Escherichia coli K12. Genetics 165: 1641–1649
Dejonghe, W, Goris, J, Dierickx, A, De Dobbeleer, V, Crul, K, De Vos, P, Verstraete, W, Top, EM (2002) Diversity of 3-chloroaniline and 3,4-dichloroaniline degrading bacteria isolated from three different soils and involvement of their plasmids in chloroaniline degradation. FEMS Microbiol. Ecol. 42: 315–325 CrossRef
Demanèche, S, Jocteur-Monrozier, L, Quiquampoix, H, Simonet, P (2001a) Evaluation of biological and physical protection against nuclease degradation of clay-bound plasmid DNA. Appl. Environ. Microbiol. 67: 293–299 CrossRef
Demanèche, S, Kay, E, Gourbière, F, Simonet, P (2001b) Natural transformation of Pseudomonas fluorescens and Agrobacterium tumefaciens in soil. Appl. Environ. Microbiol. 67: 2617–2621 CrossRef
de Vries, J, Wackernagel, W (1998) Detection of nptII (kanamycin resistance) genes in genomes of transgenic plants by marker-rescue transformation. Mol. Gen. Genet. 257: 606–613 CrossRef
de Vries, J, Wackernagel, W (2002) Integration of foreign DNA during natural transformation of Acinetobacter sp. by homology-facilitated illegitimate recombination. Proc. Natl. Acad. Sci. USA 99: 2094–2099 CrossRef
de Vries, J, Wackernagel, W (2004) Microbial horizontal gene transfer and the DNA release from transgenic crop plants. Plant Soil 266: 91–104 CrossRef
de Vries, J, Heine, M, Harms, K, Wackernagel, W (2003) Spread of recombinant DNA by roots and pollen of transgenic potato plants, identified by highly specific biomonitoring using natural transformation of an Acinetobacter sp. Appl. Environ. Microbiol. 69: 4455–4462 CrossRef
Dobrindt, U, Hochhut, B, Hentschel, U, Hacker, J (2004) Genomic islands in pathogenic and environmental microorganisms. Nature Rev. Microbiol. 2: 414–424 CrossRef
Doolittle, WF, Boucher, Y, Nesbo, LC, Douady, CJ, Andersson, JO, Roger, AJ (2003) How big is the iceberg of which organellar genes in nuclear genomes are but the tip? Phil. Trans. R. Soc. Lond. B 358: 39–58 CrossRef
Drønen, AK, Torsvik, V, Goksøyr, J, Top, EM (1998) Effect of mercury addition on plasmid incidence and gene mobilising capacity in bulk soil. FEMS Microbiol. Ecol. 27: 381-394 CrossRef
Dubnau, D (1999) DNA uptake in bacteria. Annu. Rev. Microbiol. 53: 217–244 CrossRef
Frey J, Bagdasarian M (1989) The molecular biology of IncQ plasmids. In Thomas CM, ed, Promiscuous plasmids of gram negative bacteria, Academic Press, Orlando, USA, pp 79–94
Gebhard, F, Smalla, K (1998) Transformation of Acinetobacter sp. strain BD 413 by transgenic sugar beet DNA. Appl. Environ. Microbiol. 64: 1550–1554
Gebhard, F, Smalla, K (1999) Monitoring field releases of genetically modified sugar beets for persistence of transgenic plant DNA and horizontal gene transfer. FEMS Microbiol. Ecol. 28: 261–272 CrossRef
Ghigo, JM (2001) Natural conjugative plasmids induce bacterial biofilm development. Nature 412: 442–445 CrossRef
Gillings, MR, Holley, MP, Stokes, HW, Holmes, AJ (2005) Integrons in Xanthomonas: A source of species genome diversity. PNAS 102: 4419–1124 CrossRef
Götz, A, Smalla, K (1997) Manure enhances plasmid mobilization and survival of Pseudomonas putida introduced into field soil. Appl. Environ. Microbiol. 63: 1980–1986
Grozdanov, L, Raasch, C, Schulze, J, Sonnenborn, U, Gottschalk, G, Hacker, J, Dobrindt, U (2004) Analysis of the genome structure of the nonpathogenic probiotic Escherichia coli strain Nissle 1917. J. Bacteriol. 186: 5432–5441 CrossRef
Hacker, J, Carniel, E (2001) Ecological fitness, genomic islands and bacterial pathogenicity. EMBO reports 2: 376–381 CrossRef
Hacker, J, Kaper, JB (2000) Pathogenicity islands and the evolution of microbes. Annu. Rev. Microbiol. 54: 641–679 CrossRef
Hacker, J, Hentschel, U, Dobrindt, U (2003) Prokaryotic chromosomes and disease. Science 301: 790–793 CrossRef
Hall, RM, Collis, CM (1995) Mobile gene cassettes and integrons: capture and spread of genes by site-specific recombination. Mol. Microbiol. 15: 593–600 CrossRef
Hendrickx, L, Hausner, M, Wuertz, S (2003) Natural genetic transformation in monoculture Acinetobacter sp. strain BD413 biofilms. Appl. Environ. Microbiol. 69: 1721–1727 CrossRef
Heuer, H, Smalla, K (2007) Manure and sulfadiazine synergistically increased bacterial antibiotic resistance in soil at least over two months. Environ. Microbiol. 9: 657–666 CrossRef
Heuer, H, Krögerrecklenfort, E, Egan, S, van Overbeek, L, Guillaume, G, Nikolakopoulou, TL, Wellington, EMH, van Elsas, JD, Collard, JM, Karagouni, AD, Smalla, K (2002) Gentamicin resistance genes in environmental bacteria: prevalence and transfer. FEMS Microbiol. Ecol. 42: 289–302 CrossRef
Heuer, H, Szczepanowski, R, Schneiker, S, Pühler, A, Top, EM, Schlüter, A (2004) The complete sequences of plasmids pB2 and pB3 provide evidence for a recent ancestor of the IncP-1 $\beta $ group without any accessory genes. Microbiology 150: 3591–3599 CrossRef
Heuer, H, Fox, RE, Top, EM (2007) Frequent conjugative transfer accelerates adaptation of a broad-host-range plasmid to an unfavourable Pseudomonas putida host. FEMS Microbiol. Ecol. 59: 738–748 CrossRef
Jain, R, Rivera, MC, Lake, JA (1999) Horizontal gene transfer among genomes: The complexity hypothesis. Proc. Natl. Acad. Sci. USA 96: 3801–3806 CrossRef
Jain, R, Rivera, MC, Moore, J, Lake, JA (2003) Horizontal gene transfer accelerates genome innovation and evolution. Mol. Biol. Evol. 20: 1598–1602 CrossRef
Johnsen AR, Kroer N (2006) Effects of stress and other environmental factors on horizontal plasmid transfer assessed by direct quantification of discrete transfer events. FEMS Microbiol. Ecol., DOI:10.1111/j.1574-6941.2006.00230.x
Kobayashi, N, Bailey, MJ (1994) Plasmids isolated from the sugar beet phyllosphere show little or no homology to molecular probes currently available for plasmid typing. Microbiology 140: 289–296 CrossRef
Koonin, EV, Makarova, KS, Aravind, L (2001) Horizontal gene transfer in prokaryotes: quantification and classification. Ann. Rev. Microbiol. 55: 709–742 CrossRef
Lan, L, Reeves, PR (2000) Intraspecies variation in bacterial genomes: the need for a species genome concept. Trends Microbiol. 8: 396–401 CrossRef
Larraín-Linton, J, De la Iglesia, R, Melo, F, González, B (2006) Molecular and population analyses of a recombination event in the catabolic plasmid pJP4. J. Bacteriol. 188: 6793–6801 CrossRef
Li, YH, Lau, PC, Lee, JH, Ellen, RP, Cvitkovitch, DG (2001) Natural genetic transformation of Streptococcus mutans growing in biofilms. J. Bacteriol. 183: 897–908 CrossRef
Licht, TR, Struve, C, Christensen, BB, Poulsen, RL, Molin, S, Krogfelt, KA (2003) Evidence of increased spread and establishment of plasmid RP4 in the intestine under sub-inhibitory tetracycline concentrations. FEMS Microbiol. Ecol. 44: 217–223 CrossRef
Lilley, AK, Bailey, MJ (1997) The acquisition of indigenous plasmids by a genetically marked pseudomonad population colonizing the sugar beet phytosphere is related to local environmental conditions. Appl. Environ. Microbiol. 63: 1577–1583
Lilley, AK, Fry, JD, Day, MJ, Bailey, MJ (1994) In situ transfer of an exogenously isolated plasmid between indigenous donor and recipient Pseudomonas spp. in sugar beet rhizosphere. Microbiology 140: 27–33 CrossRef
Lilley, AK, Bailey, MJ, Day, MJ, Fry, JC (1996) Diversity of mercury resistance plasmids obtained by exogenous isolation from the bacteria of sugar beet in three successive years. FEMS Microbiol. Ecol. 20: 211–227 CrossRef
Lorenz, MG, Wackernagel, W (1994) Bacterial gene transfer by natural genetic transformation in the environment. Microbiol. Rev. 58: 563–602
Lucchini S, Rowley G, Goldberg MD, Hurd D, Harrison M, Hinton JCD (2006) H-NS mediates the silencing of laterally acquired genes in bacteria. PLoS Pathog. 2: e81, DOI: 10.1371/journal.ppat.0020081
Maamar, H, Dubnau, D (2005) Bistability in the Bacillus subtilis K-state (competence) system requires a positive feedback loop. Mol. Microbiol. 56: 615–624 CrossRef
Mahillon J, Chandler M (1998) Insertion sequences. Microbiol. Mol. Biol. Rev. 62: 725–774
Mazel, D, Davies, J (1999) Antibiotic resistance in microbes. Cell. Mol. Life Sci. 56: 742–754 CrossRef
McManus, PS, Stockwell, VO, Sundin, GW, Jones, AL (2002) Antibiotic use in plant agriculture. Ann. Rev. Phytopathol. 40: 443 CrossRef
Merlin, C, Springael, D, Toussaint, A (1999) Tn4371: A modular structure encoding a phage-like integrase, a Pseudomonas-like catabolic pathway, and RP4-Ti-like transfer functions. Plasmid 41: 40–54 CrossRef
Mølbak, L, Licht, TR, Kvist, T, Kroer, N, Andersen, SR (2003) Plasmid transfer from Pseudomonas putida to the indigenous bacteria on alfalfa sprouts: characterization, direct quantification, and in situ location of transconjugant cells. Appl. Environ. Microbiol. 69: 5536–5542 CrossRef
Mølbak, L, Molin, S, Kroer, N (2007) Root growth and exudate production define the frequency of horizontal plasmid transfer in the Rhizosphere. FEMS Microbiol. Ecol. 59: 167–176 CrossRef
Nielsen, KM, van Weerelt, DM, Berg, TN, Bones, AM, Hagler, AN, van Elsas, JD (1997) Natural transformation and availability of transforming chromosomal DNA to Acinetobacter calcoaceticus in soil microcosms. Appl. Environ. Microbiol. 63: 1945–1952
Nielsen KM, Smalla K, van Elsas JD (2000) Natural transformation of Acinetobacter sp. strain BD413 with cell lysates of Acinetobacter sp., Pseudomonas fluorescens, and Burkholderia cepacia in soil microcosms. Appl. Environ. Microbiol. 66: 206–212
Normander, B, Christensen, BB, Molin, S, Kroer, N (1998) Effect of bacterial distribution and activity on conjugal gene transfer on the phylloplane of the bush bean (Phaseolus vulgaris). Appl. Environ. Microbiol. 64: 1902–1909
Ochman, H, Lawrence, JG, Groisman, EA (2000) Lateral gene transfer and the nature of bacterial innovation. Nature 405: 299–304 CrossRefPubMed
Paget, E, Simonet, P (1994) On the track of natural transformation in soil. FEMS Microbiol. Ecol. 15: 109–118 CrossRef
Paget E, Simonet P (1997) Development of engineered genomic DNA to monitor the natural transformation of Pseudomonas stutzeri in soil-like microcosms. Can. J. Microbiol. 43: 78–84
Powell BJ, Purdy KJ, Thompson IP, Bailey MJ (1993) Demonstration of tra + plasmid activity in bacteria indigenous to the phyllosphere of sugar beet; gene transfer to a recombinant pseudomonad. FEMS Microbiol. Ecol. 12: 195–206
Pukall, R, Tschäpe, H, Smalla, K (1996) Monitoring the spread of broad host and narrow host range plasmids in soil microcosms. FEMS Microbiol. Ecol. 20: 53–66 CrossRef
Reisner, A, Höller, BM, Molin, S, Zechner, EL (2006) Synergistic effects in mixed Escherichia coli biofilms: Conjugative plasmid transfer drives biofilm expansion. J. Bacteriol. 188: 3582–3588 CrossRef
Schlüter, A, Heuer, H, Szczepanowski, R, Forney, LJ, Thomas, CM, Pühler, A, Top, EM (2003) The 64,508 bp IncP-1 ${\beta} $ antibiotic multiresistance plasmid pB10 isolated from a wastewater treatment plant provides evidence for recombination between members of different branches of the IncP-1 ${\beta} $ group. Microbiology 149: 3139–3153 CrossRef
Schneiker, S, Keller, M, Dröge, M, Lanka, E, Pühler, A, Selbitschka, W (2001) The genetic organization and evolution of the broad host range mercury resistance plasmid pSB102 isolated from a microbial population residing in the rhizosphere of alfalfa. Nucl. Acids Res. 29: 5169–5181 CrossRef
Sengeløv, G, Kristensen, KJ, Sørensen, AH, Kroer, N, Sørensen, SJ (2001) Effect of genomic location on horizontal transfer of a recombinant gene cassette between Pseudomonas strains in the rhizosphere and spermosphere of barley seedlings. Curr. Microbiol. 42: 160–167 CrossRef
Sikorski, J, Teschner, N, Wackernagel, W (2002) Highly different levels of natural transformation are associated with genomic subgroups within a local population of P. stutzeri from soil. Appl. Environ. Microbiol. 68: 865–873 CrossRef
Smalla K, Heuer H (2006) How to assess the abundance and diversity of mobile genetic elements in soil bacterial communities? In Nannipieri P, Smalla K, eds, Nucleic acids in soil, Springer Berlin Heidelberg New York, pp 313–330
Smalla, K, Sobecky, PA (2002) The prevalence and diversity of mobile genetic elements in bacterial communities of different environmental habitats: insights gained from different methodological approaches. FEMS Microbiol. Ecol. 42: 165–175 CrossRef
Smalla, K, Heuer, H, Götz, A, Niemeyer, D, Krögerrecklenfort, E, Tietze, E (2000) Exogenous isolation of antibiotic resistance plasmids from piggery manure slurries reveals a high prevalence and diversity of IncQ-like plasmids. Appl. Environ. Microbiol. 66: 4854-4862 CrossRef
Smalla, K, Wieland, G, Buchner, A, Zock, A, Parzy, J, Kaiser, S, Roskot, N, Heuer, H, Berg, G (2001) Bulk and rhizosphere soil bacterial communities studied by denaturing gradient gel electrophoresis: plant-dependent enrichment and seasonal shifts revealed. Appl. Environ. Microbiol. 67: 4742–4750 CrossRef
Smalla, K, Haines, AS, Jones, K, Krögerrecklenfort, E, Heuer, H, Schloter, M, Thomas, CM (2006) Increased abundance of IncP-1 $\beta $ plasmids and mercury resistance genes in mercury polluted river sediments - first discovery of IncP-1 $\beta $ plasmids with a complex mer transposon as sole accessory element. Appl. Environ. Microbiol. 72: 7253–7259 CrossRef
Smets, BF, Barkay, T (2005) Horizontal gene transfer: Perspectives at a crossroads of scientific disciplines. Nature Rev. Microbiol. 3: 675–678 CrossRef
Smit, E, Wolters, A, van Elsas, JD (1998) Self-transmissible mercury resistance plasmids with gene-mobilizing capacity in soil bacterial populations: influence of wheat roots and mercury addition. Appl. Environ. Microbiol. 64: 1210–1219
Sørensen, SJ, Bailey, M, Hansen, LH, Kroer, N, Wuertz, S (2005) Studying plasmid horizontal transfer in situ: a critical review. Nature Rev. Microbiol. 3: 700–710 CrossRef
Springael, D, Ryngaert, A, Merlin, C, Toussaint, A, Mergeay M (2001) Occurrence of Tn4371 related mobile elements and sequences in PCB degrading bacteria. Appl. Environ. Microbiol. 67: 42–50 CrossRef
Tauch, A, Schneiker, S, Selbitschka, W, Pühler, A, van Overbeek, L, Smalla, K, Thomas, CM, Bailey, MJ, Forney, LJ, Weightman, A, Ceglowski, P, Pembroke, A, Tietze, E, Schröder, G, Lanka, E, van Elsas, JD (2002) The complete nucleotide sequence and environmental distribution of the cryptic, conjugative, BHR plasmid pIPO2 isolated from bacteria of the wheat rhizosphere. Microbiology 148: 637–653 CrossRef
Thomas, CM (2000) Paradigms of plasmid organization. Mol. Microbiol. 37: 485–491 CrossRef
Timms-Wilson TM, van Overbeek LS, Bailey MJ, Trevors JT, van Elsas JD (2001) Quantification of gene transfer in soil and the rhizosphere. In Hurst CJ, Crawford RL, Knudsen GR, McInerney MJ, Stetzenbach LD, eds, Manual of environmental microbiology, ASM Press, Washington, USA, pp 648–659
Toleman, MA, Bennett, PM, Walsh, TR (2006) Common regions e.g. orf513 and antibiotic resistance: IS91-like elements evolving complex class 1 integrons. J. Antimirob. Chemother. 58: 1–6 CrossRef
Top, EM, Springael, D (2003) The role of mobile genetic elements in bacterial adaptation to xenobiotic organic compounds. Curr. Opin. Biotechnol. 14: 262–269 CrossRef
Top, EM, Holben, WE, Forney, LJ (1995) Characterization of diverse 2,4-dichlorophenoxyacetic acid-degradative plasmids isolated from soil by complementation. Appl. Environ. Microbiol. 61: 1691–1698
Top, EM, Maltseva, OV, Forney, LJ (1996) Capture of a catabolic plasmid that encodes only 2,4-dichlorophenoxyacetic acid:alpha-ketoglutaric acid dioxygenase (TfdA) by genetic complementation. Appl. Environ. Microbiol. 62: 2470–2476
Top, EM, Springael, D, Boon, N (2002) Mobile genetic elements as tools in bioremediation of polluted soils and waters. FEMS Microbiol. Ecol. 42: 199–208 CrossRef
Tschäpe, H (1994) The spread of plasmids as a function of bacterial adaptability. FEMS Microbiol. Ecol. 15: 23–32 CrossRef
Van Elsas, JD, McSpadden Gardener, BB, Wolters, AC, Smit E (1998) Isolation, characterization, and transfer of cryptic gene-mobilizing plasmids in the wheat rhizosphere. Appl. Environ. Microbiol. 64: 880–889
Van Elsas JD, Fry JC, Hirsch P, Molin S (2000) Ecology of plasmid transfer and spread. In Thomas CM, ed, The horizontal gene pool: bacterial plasmids and gene spread, Harwood Scientif. Publ., UK, pp 175–206
Van Elsas, JD, Turner, S, Bailey, MJ (2003) Horizontal gene transfer in the phytosphere. New Phytol. 157: 525–537 CrossRef
Van Elsas JD, Turner S, Trevors JT (2006) Bacterial conjugation in soil. In Nannipieri P, Smalla K, eds, Nucleic Acids and Proteins in Soil, Springer Berlin Heidelberg, pp 331–353
Vaneechoutte M, Young DM, Ornston LN, de Baere T, Nemec A, Van der Reijden T, Carr E, Tjernberg I, Dijkshoorn L (2006) Naturally transformable Acinetobacter sp. strain ADP1 belongs to the newly described species Acinetobacter baylyi. Appl. Environ. Microbiol. 72: 932–936
van Overbeek, LS, Wellington, EMH, Egan, S, Smalla, K, Heuer, H, Collard, JM, Guillaume, G, Karagouni, AD, Nikolakopoulou, TL, van Elsas, JD (2002) Prevalence of streptomycin resistance genes in bacterial populations in European habitats. FEMS Microbiol. Ecol. 42: 277–288 CrossRef
Vivian, A, Murillo, J, Jackson, RW (2001) The roles of plasmids in phytopathogenic bacteria: mobile arsenals? Microbiology 147: 763–780 CrossRef
Watanabe, T (1963) Infective heredity of multiple drug resistance in bacteria. Bacteriol. Rev. 27: 87–115
Widmer F, Seidler RJ, Watrud LS (1996) Sensitive detection of transgenic plant marker gene persistence in soil microcosms. Mol. Ecol. 5: 603–613
Widmer, F, Seidler, RJ, Donegan, KK, Reed, GL (1997) Quantification of transgenic plant marker gene persistence in the field. Mol. Ecol. 6: 1–7 CrossRef
Witte, W (1998) Medical consequences of antibiotic use in agriculture. Science 279: 996–997 CrossRef
Wommack, KE, Colwell, RR (2000) Virioplankton: viruses in aquatic ecosystems. Microbiol. Mol. Biol. Rev. 64: 69–114 CrossRef
Zechner EL, de la Cruz F, Eisenbrandt R, Grahn AM, Koraimann G, Lanka E, Muth G, Pansegrau W, Thomas CM, Wilkins BM, Zatyka M (2000) Conjugative-DNA transfer processes. In Thomas CM, ed, The horizontal gene pool: bacterial plasmids and gene spread, Harwood Scientif. Publ., UK, pp 87–174
Zhang, X-X, Lilley, AK, Bailey, MJ, Rainey, PB (2004) The indigenous Pseudomonas plasmid pQBR103 encodes plant-inducible genes, including three putative helicases. FEMS Microbiol. Ecol. 51: 9–17 CrossRef
Zhao, Y, Ma, Z, Sundin, GW (2005) Comparative genomic analysis of the pPT23A plasmid family of Pseudomonas syringae. J. Bacteriol. 187: 2113–2126 CrossRef