Survival of free DNA encoding antibiotic resistance from transgenic maize and the transformation activity of DNA in ovine saliva, ovine rumen fluid and silage effluent

Abstract

To assess the likelihood that the bla gene present in a transgenic maize line may transfer from plant material to the microflora associated with animal feeds, we have examined the survival of free DNA in maize silage effluent, ovine rumen fluid and ovine saliva. Plasmid DNA that had previously been exposed to freshly sampled ovine saliva was capable of transforming competent Escherichia coli cells to ampicillin resistance even after 24 h, implying that DNA released from the diet could provide a source of transforming DNA in the oral cavity of sheep. Although target DNA sequences could be amplified by polymerase chain reaction from plasmid DNA after a 30-min incubation in silage effluent and rumen contents, only short term biological activity, lasting less than 1 min, was observed in these environments, as shown by transformation to antibiotic resistance. These experiments were performed under in vitro conditions; therefore further studies are needed to elucidate the biological significance of free DNA in the rumen and oral cavities of sheep and in silage effluent. ß

Scientific Opinion on applications EFSA‐GMO‐UK‐2005‐09 and EFSA‐GMO‐RX‐MON531×MON1445 for the placing on the market of food and feed produced from or containing ingredients produced from insect‐resistant and herbicide‐tolerant genetically modified cotton MON 531 × MON 1445, and for the renewal of authorisation of existing products produced from cotton MON 531 × MON 1445, both under Regulation (EC) No 1829/2003 from Monsanto

“…Several bacterial species with the potential to develop competence belong to the common gut microbial community In contrast, some studies have shown that introduced bacteria can be naturally transformed in the oral cavity of humans and animals (Duggan et al, 2000(Duggan et al, , 2003Mercer et al, 1999aMercer et al, , 1999bMercer et al, , 2001. to take up and recombine extracellular DNA.…”

Scientific Opinion on application (EFSA-GMO-UK-2008-60) for placing on the market of genetically modified herbicide tolerant maize GA21 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003 from Syngenta Seeds

“…However, competence development and transformation of such bacteria with genomic DNA of plants has not been observed in the lower gastrointestinal tract even with optimised model systems providing a selective advantage (Nordgård et al, 2007;EFSA, 2009a;Rizzi et al, 2012). In contrast, some studies have shown that introduced bacteria can be naturally transformed in the oral cavity of humans and animals (Duggan et al, 2000(Duggan et al, , 2003Mercer et al, 1999aMercer et al, ,b, 2001Rizzi et al, 2012). Once the recombinant DNA is taken up, it must integrate into the recipient genome to persist during host replication.…”

Scientific Opinion on application EFSA‐GMO‐RX‐MON531 for renewal of the authorisation for continued marketing of existing cottonseed oil, food additives, feed materials and feed additives produced from MON 531 cotton that were notified under Articles 8(1)(a), 8(1)(b) and 20(1)(b) of Regulation (EC) No 1829/2003 from Monsanto

“…Several bacterial species with the potential to develop competence belong to the common gut microbial community (EFSA, 2009;Rizzi et al, 2011). In contrast, some studies have shown that introduced bacteria can be naturally transformed in the oral cavity of humans and animals (Duggan et al, 2000(Duggan et al, , 2003Mercer et al, 1999aMercer et al, , 1999bMercer et al, , 2001. In contrast, some studies have shown that introduced bacteria can be naturally transformed in the oral cavity of humans and animals (Duggan et al, 2000(Duggan et al, , 2003Mercer et al, 1999aMercer et al, , 1999bMercer et al, , 2001.…”