ABSTRACT
Vibrio parahaemolyticus causes acute gastroenteritis associated with the consumption of contaminated raw or under cooked seafood. The virulence of vibrio parahaemolyticus is initially attributed to the production of a thermostable direct hemolysin [TDH]. The survey of different concentrations of garlic essential oil [Allium sativum] on MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus. The effects of garlic essential oil at concentrations of 0, 0.005, 0.015, 0.03 and 0.045% on the MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus were studied in BHI model. MIC and MBC of garlic essential oil was estimated 0.03%. The essential oil showed significant effect on toxin production, Titers of TDH production in 0 and 0.005% were 1/256 comparing to 1.64 in 0.015% concentration of EO. Concentrations of 0.005 and 0.015% of garlic essential oil reduced the bacterial growth rate significantly [p<0.05] compared to the control group. Garlic essential oil showed to be effective against bacterial growth and production of TDH toxin. Its potential application in food systems may be suggested
ABSTRACT
Zataria multiflora Boiss. is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current foodborne intoxications. The present study was conducted to evaluate the antimicrobial activity of Zataria multiflora Boiss. Essential oil on Escherichia coil 0157:H7. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of Zataria multiflora Boiss. Essential oil [EO] for Escherichia coil 0157:H7 at 35°C, the effect of subinhibitory concentrations of EO on growth curve of bacteria up to 24 hours at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. MIC and MBC of EO which have been evaluated were 0.04 and 0.06%, respectively the effect of subinhibitory concentrations of EO on bacterial growth curve during 24 hours has been determined by spectrophotometer device at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. Subihibitory concentrations of EO, significantly, decreased the production of Stx2 at 35°C in a dose dependent manner. The results showed that Zataria multiflora Boiss. Essential oil had inhibitory effect on Escherichia coli 0157:H7 and it can be used as a natural preservative in food industry