title: Antimicrobial activity of essential oils and structurally related synthetic food additives towards selected pathogenic and beneficial gut bacteria.
abstract: OBJECTIVE
  To assess the potential of essential oils and structurally related synthetic food additives in reducing bacterial pathogens in swine intestinal tract.
  
  
  RESULTS
  The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Among 66 essential oils/compounds that exhibited > or =80% inhibition towards Salmonellatyphimurium DT104 and Escherichia coli O157:H7, nine were further studied. Most of the oils/compounds demonstrated high efficacy against S. typhimurium DT104, E. coli O157:H7, and E. coli with K88 pili with little inhibition towards lactobacilli and bifidobacteria. They were also tolerant to the low pH. When mixed with pig cecal digesta, these oils/compounds retained their efficacy against E. coli O157:H7. In addition, they significantly inhibited E. coli and coliform bacteria in the digesta, but had little effect on the total number of lactobacilli and anaerobic bacteria.
  
  
  CONCLUSIONS
  Some essential oils/compounds demonstrated good potential, including efficacy, tolerance to low pH, and selectivity towards bacterial pathogens, in reducing human and animal bacterial pathogens in swine intestinal tract.
  
  
  CONCLUSIONS
  This study has identified candidates of essential oils/compounds for in vivo studies to develop antibiotic substitutes for the reduction of human and animal bacterial pathogens in swine intestinal tract.
authors.affiliation: Food Research Program, Agriculture and Agri-Food Canada, Guelph, Ont., Canada.
authors.forename: W
authors.initials: W
authors.lastname: Si
authors.forename: J
authors.initials: J
authors.lastname: Gong
authors.forename: R
authors.initials: R
authors.lastname: Tsao
authors.forename: T
authors.initials: T
authors.lastname: Zhou
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.forename: C
authors.initials: C
authors.lastname: Poppe
authors.forename: R
authors.initials: R
authors.lastname: Johnson
authors.forename: Z
authors.initials: Z
authors.lastname: Du
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001644:Bifidobacterium / Q000187:drug effects; D015169:Colony Count, Microbial / Q000379:methods; D003470:Culture Media; D004355:Drug Stability; D019453:Escherichia coli O157 / Q000187:drug effects*; D005503:Food Additives / Q000494:pharmacology*; D005516:Food Microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects*; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D005503:Food Additives; D009822:Oils, Volatile