title: Development of a nonantibiotic dominant marker for positively selecting expression plasmids in multivalent Salmonella vaccines.
abstract: We report the novel application of a herbicide-resistance-based dominant marker for the positive selection of expression plasmids in Salmonella serovar vaccines. The beta-lactamase gene of the plasmid pTETnir15, which expresses fragment C of tetanus toxin (TetC), has been replaced with the bar gene marker. The new plasmid pBAT1 can be positively selected in vitro within Salmonella serovars in the presence of the herbicide DL-phosphinothricin. The expression of TetC remains unaltered, and the Salmonella enterica serovar Typhimurium vaccine strain is stable and immunogenic in vivo.
authors.affiliation: Department of Microbiology & Immunology, The Medical School, University of Newcastle, Newcastle NE2 4HH, United Kingdom.
authors.forename: H V
authors.initials: HV
authors.lastname: McNeill
authors.forename: K A
authors.initials: KA
authors.lastname: Sinha
authors.forename: C E
authors.initials: CE
authors.lastname: Hormaeche
authors.forename: J J
authors.initials: JJ
authors.lastname: Lee
authors.forename: C M
authors.initials: CM
authors.lastname: Khan
mesh_terms: D000123:Acetyltransferases / Q000235:genetics*; D000613:Aminobutyrates / Q000378:metabolism*; D004351:Drug Resistance / Q000235:genetics; D015870:Gene Expression; D005799:Genes, Dominant; D005818:Genetic Engineering / Q000379:methods; D005819:Genetic Markers; D006540:Herbicides / Q000378:metabolism; D010957:Plasmids; D012641:Selection, Genetic; D012703:Serotyping; D014436:Typhoid-Paratyphoid Vaccines / Q000235:genetics* / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000613:Aminobutyrates; D005819:Genetic Markers; D006540:Herbicides; D014436:Typhoid-Paratyphoid Vaccines; D014614:Vaccines, Synthetic; C003121:phosphinothricin; D000123:Acetyltransferases; C056243:phosphinothricin N-acetyltransferase