67 research outputs found
Influence of exercise on the activity and the distribution between free and bound forms of glycolytic and associated enzymes in tissues of horse mackerel
Effect of hypoxia on the activity and binding of glycolytic and associated enzymes in sea scorpion tissues
An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats
Background: Horizontal gene transfer through natural transformation of members of the microbiota of the lower gastrointestinal tract (GIT) of mammals has not yet been described. Insufficient DNA sequence similarity for homologous recombination to occur has been identified as the major barrier to interspecies transfer of chromosomal DNA in bacteria. In this study we determined if regions of high DNA similarity between the genomes of the indigenous bacteria in the GIT of rats and feed introduced DNA could lead to homologous recombination and acquisition of antibiotic resistance genes.
Results: Plasmid DNA with two resistance genes (nptII and aadA) and regions of high DNA similarity to 16S rRNA and 23S rRNA genes present in a broad range of bacterial species present in the GIT, where constructed and added to standard rat feed. Six rats, with a normal microbiota, were fed DNA containing pellets daily over four days before sampling of the microbiota from the different GI compartments (stomach, small intestine, cecum and colon). In addition, two rats were included as negative controls. Antibiotic resistant colonies growing on selective media were screened for recombination with feed introduced DNA by PCR targeting unique sites in the putatively recombined regions.
Conclusions: The analyses showed that extensive ingestion of DNA (100 \ub5g plasmid) per day did not lead to increased proportions of kanamycin resistant bacteria, nor did it produce detectable transformants among the aerobic microbiota examined for 6 rats (detection limit <1 transformant per 1.1 x 108 cultured bacteria). The key methodological challenges to HGT detection in animal feedings trials are identified and discussed
Molecular insights into land snail neuropeptides through transcriptome and comparative gene analysis
What evidence exists on the impact of governance type on the conservation effectiveness of forest protected areas? Knowledge base and evidence gaps
Control of glycolytic enzyme binding: effect of changing enzyme substrate concentrations onin vivo enzyme distributions
Protein kinase involvement in land snail aestivation and anoxia: Protein kinase A kinetic properties and changes in second messenger compounds during depressed metabolism
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