title: Efficacy of Plant-Derived Antimicrobials in Controlling Enterohemorrhagic Escherichia coli Virulence In Vitro.
abstract: Escherichia coli O157:H7 is a major foodborne pathogen that can cause serious human illness characterized by hemorrhagic diarrhea and kidney failure. The pathology of enterohemorrhagic E. coli O157:H7 (EHEC) infection is primarily mediated by verotoxins, which bind to the globotriaosylceramide receptor on host cells. Antibiotics are contraindicated for treating EHEC infection because they lead to increased verotoxin release, thereby increasing the risk of renal failure and death in patients. Thus, alternative strategies are needed for controlling EHEC infections in humans. This study investigated the effect of subinhibitory concentrations of five plant-derived antimicrobial agents (PDAs) that are generally considered as safe, i.e., trans-cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on EHEC motility, adhesion to human intestinal epithelial cells, verotoxin production, and virulence gene expression. All tested PDAs reduced EHEC motility and attachment to human intestinal epithelial cells (P < 0.05) and decreased verotoxin synthesis by EHEC. The reverse transcription real-time PCR data revealed that PDAs decreased the expression of critical virulence genes in EHEC (P < 0.05). The results collectively suggest that these PDAs could be used to reduce EHEC virulence, but follow-up studies in animal models are necessary to validate these findings.
authors.affiliation: Department of Veterinary Public Health & Epidemiology, Veterinary College & Research Institute, Orathanadu, Tamil Nadu, India 614 625.
authors.forename: Sangeetha Ananda
authors.initials: SA
authors.lastname: Baskaran
authors.affiliation: Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55108, USA.
authors.forename: Anup
authors.initials: A
authors.lastname: Kollanoor-Johny
authors.affiliation: Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: Meera Surendran
authors.initials: MS
authors.lastname: Nair
authors.affiliation: Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: Kumar
authors.initials: K
authors.lastname: Venkitanarayanan
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D054324:Enterohemorrhagic Escherichia coli; D004927:Escherichia coli Infections; D019453:Escherichia coli O157 / Q000187:drug effects; D029968:Escherichia coli Proteins; D006801:Humans; D062385:Hydroxybenzoates / Q000494:pharmacology; D014774:Virulence / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents; D029968:Escherichia coli Proteins; D062385:Hydroxybenzoates; C017704:beta-resorcylic acid
keywords: Escherichia coli O157:H7; Plant-derived antimicrobial agents; Verotoxin