title: High-frequency conjugation system facilitates biofilm formation and pAMbeta1 transmission by Lactococcus lactis.
abstract: The importance of conjugation as a mechanism to spread biofilm determinants among microbial populations was illustrated with the gram-positive bacterium Lactococcus lactis. Conjugation triggered the enhanced expression of the clumping protein CluA, which is a main biofilm attribute in lactococci. Clumping transconjugants further transmitted the biofilm-forming elements among the lactococcal population at a much higher frequency than the parental non-clumping donor. This cell-clumping-associated high-frequency conjugation system also appeared to serve as an internal enhancer facilitating the dissemination of the broad-host-range drug resistance gene-encoding plasmid pAMbeta1 within L. lactis, at frequencies more than 10,000 times higher than those for the non-clumping parental donor strain. The implications of this finding for antibiotic resistance gene dissemination are discussed.
authors.affiliation: Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Luo
authors.forename: Kai
authors.initials: K
authors.lastname: Wan
authors.forename: Hua H
authors.initials: HH
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D003227:Conjugation, Genetic; D005144:F Factor / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D013294:Lactococcus lactis / Q000235:genetics* / Q000254:growth & development; D008855:Microscopy, Electron, Scanning; D009561:Nisin / Q000187:drug effects; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; D009561:Nisin