scholarly journals Short-term evolution under copper stress increases probability of plasmid uptake

2019 ◽  
Author(s):  
Uli Klümper ◽  
Arnaud Maillard ◽  
Elze Hesse ◽  
Florian Bayer ◽  
Stineke van Houte ◽  
...  
Keyword(s):  
Antibiotic Resistance Gene ◽  
Copper Stress ◽  
Control Treatment ◽  
Broad Host Range ◽  
Donor Strain ◽  
Phylogenetic Distance ◽  
Direct Effects ◽  
Short Term ◽  
Term Evolution ◽  
Broad Host Range Plasmid

AbstractUnderstanding plasmid transfer dynamics remains a key knowledge gap in the mitigation of antibiotic resistance gene spread. Direct effects of exposure to stressors on plasmid uptake are well monitored. However, it remains untested whether evolution of strains under stress conditions modulates subsequent plasmid uptake. Here, we evolved a compost derived microbial community for six weeks under copper stress and non-exposed control conditions. We then tested the ability of isolated clones from both treatments to take up the broad host range plasmid pKJK5 from anE.colidonor strain. Clones pre-adapted to copper displayed a significantly increased probability to be permissive towards the plasmid compared to those isolated from the control treatment. Further, increased phylogenetic distance to the donor strain was significantly and negatively correlated with plasmid uptake probabilities across both treatments.

scholarly journals Plasmid Donor Affects Host Range of Promiscuous IncP-1β Plasmid pB10 in an Activated-Sludge Microbial Community

2005 ◽  
Vol 71 (9) ◽  
pp. 5309-5317 ◽  
Author(s):  
Leen De Gelder ◽  
Frederik P. J. Vandecasteele ◽  
Celeste J. Brown ◽  
Larry J. Forney ◽  
Eva M. Top
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Host Range ◽  
Sinorhizobium Meliloti ◽  
Ralstonia Eutropha ◽  
Rrna Gene ◽  
Broad Host Range ◽  
Donor Strain ◽  
Broad Host Range Plasmid ◽  
Mating Conditions

ABSTRACT Horizontal transfer of multiresistance plasmids in the environment contributes to the growing problem of drug-resistant pathogens. Even though the plasmid host cell is the primary environment in which the plasmid functions, possible effects of the plasmid donor on the range of bacteria to which plasmids spread in microbial communities have not been investigated. In this study we show that the host range of a broad-host-range plasmid within an activated-sludge microbial community was influenced by the donor strain and that various mating conditions and isolation strategies increased the diversity of transconjugants detected. To detect transconjugants, the plasmid pB10 was marked with lacp-rfp, while rfp expression was repressed in the donors by chromosomal lacI q. The phylogeny of 306 transconjugants obtained was determined by analysis of partial 16S rRNA gene sequences. The transconjugants belonged to 15 genera of the α- and γ-Proteobacteria. The phylogenetic diversity of transconjugants obtained in separate matings with donors Pseudomonas putida SM1443, Ralstonia eutropha JMP228, and Sinorhizobium meliloti RM1021 was significantly different. For example, the transconjugants obtained after matings in sludge with S. meliloti RM1021 included eight genera that were not represented among the transconjugants obtained with the other two donors. Our results indicate that the spectrum of hosts to which a promiscuous plasmid transfers in a microbial community can be strongly influenced by the donor from which it transfers.

scholarly journals High-Frequency Conjugation System Facilitates Biofilm Formation and pAMβ1 Transmission by Lactococcus lactis

2005 ◽  
Vol 71 (6) ◽  
pp. 2970-2978 ◽  
Author(s):  
Hongliang Luo ◽  
Kai Wan ◽  
Hua H. Wang
Keyword(s):  
Resistance Gene ◽  
Lactococcus Lactis ◽  
High Frequency ◽  
Antibiotic Resistance Gene ◽  
Broad Host Range ◽  
Donor Strain ◽  
Conjugation System ◽  
Positive Bacterium ◽  
Gene Encoding ◽  
Enhanced Expression

ABSTRACT The importance of conjugation as a mechanism to spread biofilm determinants among microbial populations was illustrated with the gram-positive bacterium Lactococcus lactis. Conjugation triggered the enhanced expression of the clumping protein CluA, which is a main biofilm attribute in lactococci. Clumping transconjugants further transmitted the biofilm-forming elements among the lactococcal population at a much higher frequency than the parental nonclumping donor. This cell-clumping-associated high-frequency conjugation system also appeared to serve as an internal enhancer facilitating the dissemination of the broad-host-range drug resistance gene-encoding plasmid pAMβ1 within L. lactis, at frequencies more than 10,000 times higher than those for the nonclumping parental donor strain. The implications of this finding for antibiotic resistance gene dissemination are discussed.

Effects of rhizobacteria on the biology and behavior of Plutella xylostella (Lepidoptera: Plutellidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 195
Author(s):  
Robson Thomaz Thuler ◽  
Fernando Henrique Iost Filho ◽  
Hamilton César De Oliveira Charlo ◽  
Sergio Antônio De Bortoli
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Insect Behavior ◽  
Control Treatment ◽  
Pupal Weight ◽  
Larval Feeding ◽  
Direct Effects ◽  
Plant Feeding ◽  
Kluyvera Ascorbata ◽  
And Behavior

Plant induced resistance is a tool for integrated pest management, aimed at increasing plant defense against stress, which is compatible with other techniques. Rhizobacteria act in the plant through metabolic changes and may have direct effects on plant-feeding insects. The objective of this study was to determine the effects of cabbage plants inoculated with rhizobacteria on the biology and behavior of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). Cabbage seeds inoculated with 12 rhizobacteria strains were sowed in polystyrene trays and later transplanted into the greenhouse. The cabbage plants with sufficient size to support stress were then infested with diamondback moth caterpillars. Later, healthy leaves suffering injuries were collected and taken to the laboratory to feed P. xylostella second instar caterpillars that were evaluated for larval and pupal viability and duration, pupal weight, and sex ratio. The reduction of leaf area was then calculated as a measure of the amount of larval feeding. Non-preference for feeding and oviposition assays were also performed, by comparing the control treatment and plants inoculated with different rhizobacterial strains. Plants inoculated with the strains EN4 of Kluyvera ascorbata and HPF14 of Bacillus thuringiensis negatively affected the biological characteristics of P. xylostella when such traits were evaluated together, without directly affecting the insect behavior.

SHORT-TERM EVOLUTION OF FLOW & MORPHOLOGY IN AN ERODIBLE MEANDERING CHANNEL WITH & WITHOUT GROYNES

2018 ◽  
Vol 74 (4) ◽  
pp. I_1147-I_1152
Author(s):  
Saroj KARKI ◽  
Yuji HASEGAWA ◽  
Masakazu HASHIMOTO ◽  
Hajime NAKAGAWA ◽  
Kenji KAWAIKE
Keyword(s):  
Short Term ◽  
Meandering Channel ◽  
Term Evolution ◽  
Flow Morphology

Effects of Dipyridamole on the Short-Term Evolution of Glomerulonephritis

Nephron ◽  
1991 ◽  
Vol 58 (1) ◽  
pp. 13-16 ◽  
Author(s):  
S. Camara ◽  
J.P. de la Cruz ◽  
M.A. Frutos ◽  
P. Sanchez ◽  
Lopez de Novales ◽  
...  
Keyword(s):  
Short Term ◽  
Term Evolution

The Effect of High Concentrations of Ethylene on Seed Germination of Douglas Fir (Pseudotsugamenziesii (Mirb.) Franco)

1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Douglas Fir ◽  
Control Treatment ◽  
Continuous Exposure ◽  
Short Term ◽  
Short Term Exposure ◽  
High Concentrations

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.

Physical modeling of the cross-shore short-term evolution of protected and unprotected beach nourishments

2010 ◽  
Vol 37 (8-9) ◽  
pp. 777-789 ◽  
Author(s):  
M. Di Risio ◽  
I. Lisi ◽  
G.M. Beltrami ◽  
P. De Girolamo
Keyword(s):  
Physical Modeling ◽  
Short Term ◽  
Term Evolution ◽  
The Cross
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