Retrotransfer or gene capture: A feature of conjugative plasmids, with ecological and evolutionary significance

SCOPUS: re.jinfo:eu-repo/semantics/publishe

Genomics of resistance plasmids isolated from wastewater treatment plants

Tennstedt T, Heuer H, Top EM, Szczepanowski R, Pühler A, Schlüter A. Genomics of resistance plasmids isolated from wastewater treatment plants. Plasmid. 2005;53(1):40-41

Invasion of pumpkinseed Lepomis gibbosus is facilitated by phenotypic plasticity across its invasion gradient

As a non-native species invades a new region, individuals at the range front are often characterised by differences in their traits and behaviours versus individuals in the established ‘core’ area. Here, differences in life history traits of invading pumpkinseed Lepomis gibbosus were assessed across a fine spatial scale in the Sarıçay Stream, Turkey, with seven locations sampled between their core area and the invasion front. Following genetic analyses that suggested the pumpkinseed all originated from the same founding population, life history trait analyses revealed pronounced differences between the sites at the core and front that were independent of environmental factors. Pumpkinseed in sites towards the invasion front were of relatively low abundance and displayed relatively high reproductive investment, with heavier gonads, higher fecundity and smaller eggs. They also had faster growth rates than pumpkinseed in sites towards the core of the invasion. The traits displayed by pumpkinseed at sites in the mid-range were intermediate between the extremes displayed by fish at core and frontal sites. These results suggested high plasticity in life history traits of these pumpkinseed across this fine-scale invasion gradient and was considered to be most likely due to responses to low intra-specific competition at the invasion front that had shifted selective pressures towards higher investment in somatic growth and reproduction

Replication functions of new broad host range plasmids isolated from polluted soils

The nucleotide sequencing of replicons isolated from three new broad host range plasmids, pMOL98, pEMT8, and pEMT3, originating from polluted soils, showed a typical organization of iteron replicons replicating by the theta mode. In the pMOL98 replicon, the origin region and the rep gene were identified in complementation experiments. Sequence comparisons showed that the regions bearing these features are highly identical to regions in pIP02T and pSB102 and that the Rep proteins (but not the origin regions) of these three plasmids show some identity to the Rep proteins of the IncW group of plasmids. This suggests that pMOL98, pIPO2T, and pSB102 constitute a new Inc/Rep family, distantly related to the IncW group, but having an incompatibility phenotype different from the IncW phenotype. The pEMT8 replicon displayed an orf whose conceptually translated product is related to the Rep proteins of four plasmids, pSD20, pSW500, pMLb, and pALC1, not yet classified into any known incompatibility group. The vegetative origins of these plasmids were not similar, suggesting that the five plasmids could belong to a new family with similar Rep proteins but different incompatibility phenotypes. The pEMT3 replicon is clearly related to IncP replicons (sequence similarities and incompatibility phenotype), although sequence comparisons revealed some divergence with respect to the two well-documented subgroups IncPα and IncPβ. This suggests that in these plasmids, despite the existence of a powerful system of centralized control over replication, maintenance, and transfer functions, plasticity and evolution of these functions are at work. Our analysis confirms the extreme genetic flexibility of plasmids and the absolute necessity of using multiple techniques (PCR, DNA sequencing, DNA chips, and databases) to analyze the role of broad host range plasmids in the capture, recombination and spread of genetic traits among bacteria. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The 64 508 bp IncP-1 beta antibiotic multiresistance plasmid pB10 isolated from a waste-water treatment plant provides evidence for recombination between members of different branches of the IncP-1 beta group

Schlüter A, Heuer H, Szczepanowski R, et al. The 64 508 bp IncP-1 beta antibiotic multiresistance plasmid pB10 isolated from a waste-water treatment plant provides evidence for recombination between members of different branches of the IncP-1 beta group. Microbiology. 2003;149:3139-3153

Effect of veterinary medicines introduced via manure into soil on the abundance and diversity of antibiotic resistance genes on their transferability.

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