title: Antibacterial effect of silver nanoparticles against four foodborne pathogens.
abstract: BACKGROUND
  There is increased demand for improved disinfection methods due to microorganisms resistant to multiple antimicrobial agents. Numerous types of disinfectants are available with different properties; but the proper disinfectant must be carefully selected for any specific application to obtain the desired antimicrobial effect.
  
  
  OBJECTIVE
  Antimicrobial effect of a commercial nanosilver product, NanoCid® L2000, against some foodborne pathogens was evaluated.
  
  
  METHODS
  Minimum inhibitory concentrations (MIC) were determined by monitoring the growth of bacteria at 600 nm, after 24 hours incubation at 35°C. Minimum bactericidal concentrations (MBC) were determined based on 3 log decrease in the viable population of the pathogens after incubation of nutrient agar plates at 35°C for 24 hours. The required exposure time for 3 log reduction in the viable population of the tested pathogens was determined as the minimum exposure time for efficient bactericidal activity.
  
  
  RESULTS
  The MIC values of Ag NPs against tested pathogens were in the range of 3.12-6.25 µg/mL. While Listeria monocytogenes showed the MIC value of 6.25 µg/mL, Escherichia coli O157:H7, Salmonella typhimurium and Vibrio parahaemolyticus all showed the MIC values of 3.12 µg/mL. However, all the pathogens showed the same MBC value of 6.25 µg/mL. To obtain an efficient bactericidal activity against E. coli O157:H7 and S. typhimurium, the exposure time should be at least ca. 6 hours., while this time was ca. 5 hours for V. parahaemolyticus and ca. 7 hours for L. monocytogenes.
  
  
  CONCLUSIONS
  Silver nanoparticles showed great antibacterial effectiveness on four important foodborne pathogens. Therefore, Ag NPs could be a good alternative for cleaning and disinfection of equipment and surfaces in food-related environments.
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, IR Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Zarei
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, IR Iran.
authors.forename: Amirhesam
authors.initials: A
authors.lastname: Jamnejad
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Elahe
authors.initials: E
authors.lastname: Khajehali
keywords: Disinfection; Microbial Sensitivity Tests; Nanoparticles; Pathogen; Silver