title: Inhibition by epigallocatechin gallate (EGCg) of conjugative R plasmid transfer in Escherichia coli.
abstract: Epigallocatechin gallate (EGCg) in tea catechins blocked or significantly diminished the transfer of conjugative R plasmid between Escherichia coli C600 with plasmid R-222 (donor) and E. coli K-12 RC85 (recipient) in a dose-dependent manner. The inhibition rates of R plasmid transfer by EGCg were 42%-67% at 50-200 microg/ml, and up to 99% at 800 microg/ml. Nevertheless, EGCg, even at the concentration of 1600 microg/ml, was not sufficient to kill E. coli cells in 1 h, as confirmed by determining viable cells after incubation with various concentrations of EGCg. The result indicates that the bactericidal activity of EGCg against the two strains was not the main factor responsible for the inhibition of R plasmid transfer. This observation suggests the possibility that tea consumption may be effective in preventing R plasmid transfer in enteric bacteria.
authors.affiliation: Department of Microbiology and Immunology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan. whzhao@med.showa-u.ac.jp
authors.forename: W H
authors.initials: WH
authors.lastname: Zhao
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: T
authors.initials: T
authors.lastname: Shimamura
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology*; D003227:Conjugation, Genetic / Q000187:drug effects*; D004269:DNA, Bacterial / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D010957:Plasmids / Q000187:drug effects*
chemical_list: D004269:DNA, Bacterial; D002392:Catechin; C045651:epigallocatechin gallate