A newEscherichia coli: Bacteroides shuttle vector, pRRI207, based on theBacteroides ruminicola plasmid replicon pRRI2

A 3.4kb cryptic plasmid, pRRI2, was isolated fromBacteroides ruminicola 223/M2/7 and used as the basis for a newBacteroides/Escherichia shuttle vector. Constructs were made incorporating pRRI2, aBacteroides erythromycin/clindamycin resistance marker and theE. coli pUC8-derived vector pHG165. One of these, pRRI207 (11 kb), was capable of introduction into strains belonging to four different species ofBacteroides (B. uniformis, B. distasonis, B. thetaiotaomicron, orB. ruminicola) either by conjugal transfer fromE. coli or by electrotransformation. pRRI207 carries several unique restriction sites derived from the pUC8 multiple cloning site. Only one of sixB. ruminicola strains tested was used successfully as a recipient for pRRI207, indicating that further modifications to transfer procedures or marker genes may be needed for wider application in this species.