title: Colicin concentrations inhibit growth of Escherichia coli O157:H7 in vitro.
abstract: Escherichia coli O157:H7 is a virulent foodborne pathogen that causes severe human illness and inhabits the intestinal tract of food animals. Colicins are antimicrobial proteins produced by E. coli strains that inhibit or kill other E. coli. In the present Study, the efficacy of three pore-forming colicins (El, N, and A) were quantified in vitro against E. coli O157:H7 strains 86-24 and 933. Colicins E1 and N reduced the growth of E. coli O157:H7 strains, but the efficacy of each colicin varied among strains. Colicin E1 was more effective against both strains of E. coli O157:H7 than colicins A and N and reduced (P < 0.05) populations of E. coli O157:H7 at concentrations <0.1 microg/ml. These potent antimicrobial proteins may potentially provide an effective and environmentally sound preharvest strategy to reduce E. coli O157:H7 in food animals.
authors.affiliation: Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, College Station, Texas 77845, USA. callaway@ffsru.tamu.edu
authors.forename: T R
authors.initials: TR
authors.lastname: Callaway
authors.forename: C H
authors.initials: CH
authors.lastname: Stahl
authors.forename: T S
authors.initials: TS
authors.lastname: Edrington
authors.forename: K J
authors.initials: KJ
authors.lastname: Genovese
authors.forename: L M
authors.initials: LM
authors.lastname: Lincoln
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: S M
authors.initials: SM
authors.lastname: Lonergan
authors.forename: T L
authors.initials: TL
authors.lastname: Poole
authors.forename: R B
authors.initials: RB
authors.lastname: Harvey
authors.forename: D J
authors.initials: DJ
authors.lastname: Nisbet
mesh_terms: D003087:Colicins / Q000096:biosynthesis / Q000494:pharmacology*; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism / Q000502:physiology*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development*; D005506:Food Contamination; D005516:Food Microbiology
chemical_list: D003087:Colicins