Transformation of an oral bacterium via chromosomal integration of free DNA in the presence of human saliva

Mercer, Derry K.; Scott, Karen P.; Melville, Claire M.; Glover, Lesley Anne; Flint, Harry J.

doi:10.1111/j.1574-6968.2001.tb10709.x

Cited by 50 publications

(17 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Transformation of S. gordonii has been shown to occur in vitro with plasmid DNA in human saliva (104). The half-life for transforming activity of both plasmid and chromosomal DNA is only 5.7 s in saliva in the mouth, but 5.7 s is sufficient for DNA uptake and protection from salivary nucleases (105). Natural genetic transformation has been reported for many oral streptococci in planktonic cultures and occurs by induction of genetic competence through a competence-stimulating peptide (CSP) signaling system (61,97).…”

Section: In Vitromentioning

confidence: 99%

Communication among Oral Bacteria

Kolenbrander

Andersen

Blehert

et al. 2002

Microbiol Mol Biol Rev

853

745

View full text Add to dashboard Cite

Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities

show abstract

Section: In Vitromentioning

confidence: 99%

Communication among Oral Bacteria

Kolenbrander

Andersen

Blehert

et al. 2002

Microbiol Mol Biol Rev

853

745

View full text Add to dashboard Cite

show abstract

“…Many oral streptococci are capable of natural transformation, which has been best studied in Streptococcus gordonii (8). Recently, it has been shown that S. gordonii can be transformed by plasmid DNA or via chromosomal integration of plasmid DNA at increased frequency in the presence of human saliva (29,30). These authors incubated plasmid DNA with human saliva or exposed the DNA to it in vivo and observed that the nucleic acid keeps its capability to transform oral streptococci in vitro.…”

mentioning

confidence: 99%

Marker Rescue Studies of the Transfer of Recombinant DNA to Streptococcus gordonii In Vitro, in Foods and Gnotobiotic Rats

Kharazmi

Sczesny

Blaut

et al. 2003

Appl Environ Microbiol

View full text Add to dashboard Cite

A plasmid marker rescue system based on restoration of the nptII gene was established in Streptococcus gordonii to study the transfer of bacterial and transgenic plant DNA by transformation. In vitro studies revealed that the marker rescue efficiency depends on the type of donor DNA. Plasmid and chromosomal DNA of bacteria as well as DNA of transgenic potatoes were transferred with efficiencies ranging from 8.1 ؋ 10 ؊6 to 5.8 ؋ 10 ؊7 transformants per nptII gene. Using a 792-bp amplification product of nptII the efficiency was strongly decreased (9.8 ؋ 10 ؊9 ). In blood sausage, marker rescue using plasmid DNA was detectable (7.9 ؋ 10 ؊10 ), whereas in milk heat-inactivated horse serum (HHS) had to be added to obtain an efficiency of 2.7 ؋ 10 ؊11 . No marker rescue was detected in extracts of transgenic potatoes despite addition of HHS. In vivo transformation of S. gordonii LTH 5597 was studied in monoassociated rats by using plasmid DNA. No marker rescue could be detected in vivo, although transformation was detected in the presence of saliva and fecal samples supplemented with HHS. It was also shown that plasmid DNA persists in rat saliva permitting transformation for up to 6 h of incubation. It is suggested that the lack of marker rescue is due to the absence of competence-stimulating factors such as serum proteins in rat saliva.

show abstract

“…Enfin, l'expression du nouveau gène surviendra si le produit recombinant encodé n'est pas létal et si les séquences régulatrices incluses aux constructions génétiques pour l'étape de transgénèse sont compatibles avec la machinerie génétique de la bactérie. L'expression effective du transgène chez la bactérie hôte et ses descendants sera tributaire de facteurs variés comme la nature des séquences promotrices et amplificatrices intégrées aux constructions, l'identité des codons composant la séquence exprimée, la présence ou non d'introns dans le gène introduit et l'homologie de séquence qu'il partage avec l'ADN de l'hôte bactérien (de Vries et Wackernagel 1998;de Vries et al 2001;Mercer et al 2001;Tepfer et al 2003).…”

Section: La Persistance Des Transgènes Dans L'environnementunclassified

Impact environnemental des cultures transgéniques

Michaud

2006

phyto

View full text Add to dashboard Cite

L’adoption à grande échelle des cultures transgéniques depuis dix ans a soulevé de nombreuses questions quant aux impacts possibles de ces nouvelles lignées végétales sur les écosystèmes agricoles et naturels. Des questions ont été soulevées, en particulier, sur le devenir des transgènes dans le milieu et sur une possible « pollution » du patrimoine génétique des organismes vivants à l’échelle des écosystèmes. Après une énumération des impacts environnementaux associés aux végétaux transgéniques, cet article de synthèse dresse un aperçu des connaissances actuelles sur le devenir – ou la migration – des transgènes dans le milieu. Les phénomènes d’hybridation et d’introgression génique en direction d’espèces ou de lignées apparentées sont d’abord abordés, après quoi sont considérés les phénomènes de transfert horizontal des transgènes en direction d’organismes non apparentés. Un article complémentaire publié dans ce même numéro traite de l’impact environnemental des protéines recombinantes encodées par les transgènes (Michaud 2005).

show abstract

Transformation of an oral bacterium via chromosomal integration of free DNA in the presence of human saliva

Cited by 50 publications

References 33 publications

Communication among Oral Bacteria

Communication among Oral Bacteria

Marker Rescue Studies of the Transfer of Recombinant DNA to Streptococcus gordonii In Vitro, in Foods and Gnotobiotic Rats

Impact environnemental des cultures transgéniques

Contact Info

Product

Resources

About