Article contents
Worst-case scenarios for horizontal gene transfer from Lactococcus lactis carrying heterologous genes to Enterococcus faecalis in the digestive tract of gnotobiotic mice
Published online by Cambridge University Press: 15 November 2003
Abstract
Since genetically modified (GM) lactic acid bacteria (LAB) might be released in open environments for future nutritional and medical applications, the purpose of this study was to determine an upper limit for the horizontal gene transfer (HGT) in the digestive tract (DT) from Lactococcus lactis carrying heterologous genes (lux genes encoding a bacterial luciferase) to Enterococcus faecalis. Two enterococcal wide host-range conjugative model systems were used: (i) a system composed of a mobilizable plasmid containing the heterologous lux genes and a native conjugative helper plasmid; and (ii) a Tn916-lux transposon. Both systems were tested under the most transfer-prone conditions, i.e. germfree mice mono-associated with the recipient E. faecalis. No transfer was observed with the transposon system. Transfers of the mobilizable plasmid carrying heterologous genes were below 102 transconjugants per g of faeces for a single donor dose and reached between 103 and 104 transconjugants per g of faeces when continuous inoculation of the donor strain was used. Once established in mice, transconjugants persisted at low levels in the mouse DT.
Keywords
- Type
- Research Article
- Information
- Copyright
- © ISBR, EDP Sciences, 2003
References
- 10
- Cited by