Stimulation of bacterial DNA transformation by cattle saliva: implications for using genetically modified plants in animal feed

Шедова, Е. Н.; Albrecht, Christiane; Zverlov, Vladimir V.; Schwarz, Wolfgang H.

doi:10.1007/s11274-008-9910-4

Cited by 2 publications

(1 citation statement)

References 38 publications

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“…The oral cavity is the first place feed introduced DNA enters the GIT and therefore also contains the highest amount of DNA ingested. In general, a highly time-limited stability of DNA and ability to transform defined model bacteria introduced to saliva or stomach fluids has been observed in vitro and in vivo [ 16 , 30 - 34 ]. Only few studies have investigated the occurrence of natural transformation in the compartments of the lower GIT.…”

Section: Introductionmentioning

confidence: 99%

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

et al. 2012

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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 ( npt I and aad A) 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, were 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. No transformants were identified among 441 tested isolates. Conclusions The analyses showed that extensive ingestion of DNA (100 μg 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 × 10 8 cultured bacteria). The key methodological challenges to HGT detection in animal feedings trials are identified and discussed. This study is consistent with other studies suggesting natural transformation is not detectable in the GIT of mammals.

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Section: Introductionmentioning

confidence: 99%

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

et al. 2012

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The Stability and Degradation of Dietary DNA in the Gastrointestinal Tract of Mammals: Implications for Horizontal Gene Transfer and the Biosafety of GMOs

Rizzi

Raddadi

Sorlini

et al. 2012

Critical Reviews in Food Science and Nutrition

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The fate of dietary DNA in the gastrointestinal tract (GIT) of animals has gained renewed interest after the commercial introduction of genetically modified organisms (GMO). Among the concerns regarding GM food, are the possible consequences of horizontal gene transfer (HGT) of recombinant dietary DNA to bacteria or animal cells. The exposure of the GIT to dietary DNA is related to the extent of food processing, food composition, and to the level of intake. Animal feeding studies have demonstrated that a minor amount of fragmented dietary DNA may resist the digestive process. Mammals have been shown to take up dietary DNA from the GIT, but stable integration and expression of internalized DNA has not been demonstrated. Despite the ability of several bacterial species to acquire external DNA by natural transformation, in vivo transfer of dietary DNA to bacteria in the intestine has not been detected in the few experimental studies conducted so far. However, major methodological limitations and knowledge gaps of the mechanistic aspects of HGT calls for methodological improvements and further studies to understand the fate of various types of dietary DNA in the GIT.

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Stimulation of bacterial DNA transformation by cattle saliva: implications for using genetically modified plants in animal feed

Cited by 2 publications

References 38 publications

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

The Stability and Degradation of Dietary DNA in the Gastrointestinal Tract of Mammals: Implications for Horizontal Gene Transfer and the Biosafety of GMOs

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