Molecular characterization of conjugative plasmids in pesticide tolerant and multi-resistant bacterial isolates from contaminated alluvial soil

Anjum, Reshma; Grohmann, Elisabeth; Malik, Abdul

doi:10.1016/j.chemosphere.2011.02.002

Cited by 45 publications

(23 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One way to address this central question is to analyze the accessory gene content of extant pools of plasmids in various environments. Unfortunately, most studies on plasmid diversity have focused on plasmids that were isolated based on a trait of interest, such as virulence or resistance to or catabolism of antimicrobials or pollutants, and from habitats and bacteria that are under strong se- lection, such as polluted soils and water bodies, wastewater treatment plants, or known pathogens (18,(62)(63)(64)(65)(66)(67)(68). Not surprisingly, such plasmids contain accessory genes that encode the selected host-beneficial traits.…”

Section: Discussionmentioning

confidence: 99%

“…Most of our knowledge about accessory genes comes from plasmids that were isolated based on specific phenotypes that often match the environmental selection pressures. For example, plasmids isolated from bacteria found in soil contaminated with pesticides and heavy metals encode degradation of, or resistance to, these xenobiotics (18). The same is true for wastewaters known to contain pollutants such as antibiotics and organic and inorganic xenobiotics (19)(20)(21)(22).…”

mentioning

confidence: 96%

See 1 more Smart Citation

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Brown

Sen

Yano

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

c Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured from freshwater sources without selecting for a particular phenotype or cultivating their host. To do this, triparental matings were used such that the only required phenotype was the plasmid's ability to mobilize a nonconjugative plasmid. Based on complete genome sequences of 10 plasmids, only 5 carried identifiable accessory gene regions, and none carried antibiotic resistance genes. The plasmids belong to four known incompatibility groups (IncN, IncP-1, IncU, and IncW) and two potentially new groups. Eight of the plasmids were shown to have a broad host range, being able to transfer into alpha-, beta-, and gammaproteobacteria. Because of the absence of antibiotic resistance genes, we resampled one of the sites and compared the proportion of captured plasmids that conferred antibiotic resistance to their hosts with the proportion of such plasmids captured from the effluent of a local wastewater treatment plant. Few of the captured plasmids from either site encoded antibiotic resistance. A high diversity of plasmids that encode no or unknown accessory functions is thus readily found in freshwater habitats. The question remains how the plasmids persist in these microbial communities.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 96%

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Brown

Sen

Yano

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Specifically, IncP-1 plasmids are highly promiscuous plasmids and were reported to carry genes coding for enzymes involved in degradation of different xenobiotic compounds (10)(11)(12). Correspondingly, it has been observed that prolonged exposure to pesticides enriches for bacterial populations carrying IncP-1 plasmids (13,14,37).…”

mentioning

confidence: 99%

Shifts in Abundance and Diversity of Mobile Genetic Elements after the Introduction of Diverse Pesticides into an On-Farm Biopurification System over the Course of a Year

Dealtry

Holmsgaard

Dunon

et al. 2014

Appl Environ Microbiol

View full text Add to dashboard Cite

f Biopurification systems (BPS) are used on farms to control pollution by treating pesticide-contaminated water. It is assumed that mobile genetic elements (MGEs) carrying genes coding for enzymes involved in degradation might contribute to the degradation of pesticides. Therefore, the composition and shifts of MGEs, in particular, of IncP-1 plasmids carried by BPS bacterial communities exposed to various pesticides, were monitored over the course of an agricultural season. PCR amplification of total community DNA using primers targeting genes specific to different plasmid groups combined with Southern blot hybridization indicated a high abundance of plasmids belonging to IncP-1, IncP-7, IncP-9, IncQ, and IncW, while IncU and IncN plasmids were less abundant or not detected. Furthermore, the integrase genes of class 1 and 2 integrons (intI1, intI2) and genes encoding resistance to sulfonamides (sul1, sul2) and streptomycin (aadA) were detected and seasonality was revealed. Amplicon pyrosequencing of the IncP-1 trfA gene coding for the replication initiation protein revealed high IncP-1 plasmid diversity and an increase in the abundance of IncP-1␤ and a decrease in the abundance of IncP-1 over time. The data of the chemical analysis showed increasing concentrations of various pesticides over the course of the agricultural season. As an increase in the relative abundances of bacteria carrying IncP-1␤ plasmids also occurred, this might point to a role of these plasmids in the degradation of many different pesticides.

show abstract

“…Moreover, the screening of bacteria isolated by standard cultivation techniques for the presence of plasmids only allows for analysis of a small proportion of bacteria accessible to standard techniques. The application of new approaches, such as the exogenous plasmid isolation techniques or the PCR-based detection of mobile genetic elements in total community DNA (Couturier et al 1988;Götz et al 1996;Nikolakopoulou et al 2008;Rahube and Yost 2010;Anjum et al 2011), now broadens our view of the plasmid pool present in bacteria from different environmental habitats. Plasmid-mediated gene exchange between bacteria plays an important role in bacterial adaptation and flexibility, therefore exogenous isolation of MGEs (mobile genetic elements) designated exogenous plasmid isolation, when such mobile genetic elements are plasmids, has been developed to capture transferable plasmids directly from natural microbial community using bacterial conjugation systems (Smalla et al 2000(Smalla et al , 2006Miyazaki et al 2006;De Boever et al 2007;Binh et al 2008).…”

Section: Introductionmentioning

confidence: 98%

“…Horizontal gene transfer studies on bacteria colonizing natural or semi natural environments are important for understanding of the mechanism leading to bacterial adaptation to a given set of conditions (Thomas 2000;Smets and Barkay 2005;De Gelder et al 2008), for assessing the risks associated with spread of resistance genes to bacteria that infect humans and animals, and for the identification of bacterial populations in the environment that might play a role as reservoirs for resistance genes (Mazodier and Davies 1991;Auerbach et al 2007;Ansari et al 2008;Malik et al 2008;He et al 2010;Anjum et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Exogenous isolation of conjugative plasmids from pesticide contaminated soil

Anjum

Grohmann

Malik

2011

World J Microbiol Biotechnol

Self Cite

View full text Add to dashboard Cite

Exogenous plasmid isolation method was used to assess conjugative plasmids conferring pesticide tolerance/multiple metal and antibiotic resistance from contaminated soil using bacteria detached from soil samples as a donor and rifampicin resistant E. coli HMS as a recipient strain on mineral salt agar medium supplemented with γ-HCH, and antibiotics ampicillin, tetracycline, chloramphenicol and kanamycin. Transconjugants were obtained on ampicillin (10 μg/ml) and tetracycline (20 μg/ml) amended MSA plates and frequency of ampicillin and tetracycline resistance gene transfer was 7.2 × 10(-6) and 9.2 × 10(-4) transconjugants/recipient, respectively. PCR typing methods were used to assess the presence of plasmids of the incompatibility groups IncP, IncN, IncW, IncQ and rolling circle plasmids of pMV158 type in DNA derived from transconjugants. All transconjugants were PCR amplified for the detection of Inc group plasmids and rolling circle plasmids of pMV158 family in which TM2, 3, 4, 11 and 12 (tet) transconjugants gave PCR products with the IncP-specific primers for both replication and transfer functions (trfA2 (IncP) and oriT (IncP)), while TM 14 (amp) gave an IncP specific PCR product for the replication gene trfA2 (IncP) only. TM15, 16, 18 and 21 (amp) gave a PCR product for the IncW-specific oriT (IncW). Out of 24 transconjugants, only TM 5 (tet) gave a PCR product with the pMV158 specific primer pair for oriT (RC). Our findings indicate that Inc group plasmids and rolling circle plasmids of pMV158 type may be responsible for transferring multiple antibiotic resistance genes among the bacterial soil community.

show abstract

Molecular characterization of conjugative plasmids in pesticide tolerant and multi-resistant bacterial isolates from contaminated alluvial soil

Cited by 45 publications

References 30 publications

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes

Shifts in Abundance and Diversity of Mobile Genetic Elements after the Introduction of Diverse Pesticides into an On-Farm Biopurification System over the Course of a Year

Exogenous isolation of conjugative plasmids from pesticide contaminated soil

Contact Info

Product

Resources

About