[Effect of Zataria multiflora boiss. essential oil on growth curve and shigatoxin 2 production of enterohemorrhagic Escherichia coli O157:H7]

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

[Study of chemical composition of essential oil of Afsantine [Artemisia absinthium] and inhibitory effects of the essential oil and its aqueous and alcoholic extracts on some food borne bacterial pathogens]

Increasing human knowledge about adverse effects of chemical preservatives has increased public interest to consume products with natural preservatives such as plant extract and their essential oils. In this study chemical composition of essential oil of Afsantine and antibacterial effect of its essential oil and aqueous, ethanolic and methanolic extracts against the most important food borne pathogens, Salmonella typhimurium, Listeria monocytogenes, E. coli O157:H7, Bacillus cereus and Staphylococcus aureus were evaluated. Gas Chromatography-Mass Spectrometry [GC-MS] method was used for chemical composition analysis of the essential oil. Disk diffusion method was done to screen bacterial sensitivity. The Minimum Inhibitory Concentrations [MIC] of extracts were evaluated by broth micro-dilution method. The essential oil components were identified and the major constituents of the oil were Beta Thujone [29.75%] and Phellandrene [20.20%]. In disk diffusion method the most sensitive strain to the essential oil and the extracts was S. typhimurium and E.coli O157:H7. MICs of Afsantine essential oil against S. aureus and L. monocytogenes were estimated 3000 ppm. The methanolic extract showed antimicrobial activity against L. monocytogenes, E.coli O157:H7, B. cereus and S. aureus were estimated 10, 10, 8 and 4 mg ml-1, respectively. The results of this study revealed that the essential oil and methanlic extract of Afsantine have greater antimicrobial effects on given strains and might be used as a natural preservative in food system.

[Antibacterial effect of aqueous and alcoholic extracts from petal of saffron [Crocus sativus L.] on some foodborne bacterial pathogens]

Health concerns due to adverse effects of chemical preservatives have increased public interest to consuming preservative-free products or product containing natural preservatives such as plant extract and their essential oils. In this study the antibacterial effect of aqueous, ethanolic and methanolic extracts from petal of saffron against the most important foodborne pathogens Salmonella typhimurium, Listeria monocytogenes, E. coli O157: H7, Bacillus cereus and Staphylococcus aureus were evaluated. Disk diffusion method was done to screen bacterial sensitivity. The minimum inhibitory concentration [MIC] of extracts were evaluated by agar dilution and broth microdilution method. The most sensitive strain to extracts was S. typhimurium, and the most resistant strains were S. aureus and E. coli O157:H7. MICs of all extracts were estimated 40 mgml[-1], against all bacteria using agar dilution method. The aqua and methanolic extracts showed antimicrobial activity against all of bacteria by broth microdilution and MIC estimated 40 mgml[-1], however MIC of ethanolic extracts estimated 40 mgml[-1] for L. monocytogenes, S. aureus and B. cereus, while the MICs for S. typhimurium and E. coli O157:H7 were estimated >40 mgml[-1]. The results of this study revealed that the studied extracts might be potential sources of natural antimicrobial agents, and propose their potential application in food system as a natural preservative

[Determination of minimum inhibitory concentration [MIC] of zataria multiflora boiss. essential oil and lysozim on L. monocytogenes]

Application of natural compounds, including essential oils [EOs] and lysozyme is an effective method against growth of bacterial pathogens in foods. Determination of minimum inhibitory concentration [MIC] of lysozyme and Zataria multiflora Boiss. essential oil on L. monocytogenes. In this study different concentrations of lysozyme and Zataria multiflora Boiss. EO were used alone and in combination on BHI broth to determine MIC of Zataria multiflora Boiss. EO and lysozyme with macro dilution and micro dilution methods and effect of sub inhibitory concentrations of them on bacterial growth curve of L. monocytogenes. The minimum inhibitory concentration [MIC] of Z. multiflora Boiss EO was estimated ?0.04 using macro and microdilution. lysozyme at the highest concentration [1000 microg/ ml] was not effective in inhibition of bacterial growth and no MIC value obtained. Combination of EO and Lysozyme decreased the MIC value to%0.02 and 250microg/ mlfor Z. multifloraBoiss. EO and lysozyme, respectively. The results of growth curve analysis showed that combination was effective in increasing the lag phase. Z. multiflora Boiss and lysozyme showed to be effective against bacterial growth and its potential application in food systems may be suggested

[Effect of zataria multiflora boiss. Essential oil on growth and enterotoxin E production of staphylocuccus aureus ATCC 29213]

Z. 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 Z. multiflora Boiss. Essential oil on Staphylocuccus aureus ATCC 29213. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of Z. multiflora Boiss. essential oil [EO] for Staphylocuccus aureus at 35[degree sign]C, the effect of subihibitory concentrations of EO on growth of bacteria up to 72 hours and also production of entertoxin E [SEE], all at 25 and 35[degree sign]C has been determined. MIC and MBC of EO which have been evaluated in 0.005 - 0.06% [V/V] were 0.03 and 0.04%, respectively. Colony counting during 72h showed that 75%MIC of EO in 72h reduced 3 log [cfu/ml] at 25[degree sign]C and 2, 2 and log [cfu/ml] at 35[degree sign]C in comparison with control culture. Subihibitory concentrations of EO, significantly, decreased the production of SEE at both 25 and 35[degree sign]C in a dose dependent manner. The results showed that Z. multiflora Boiss. essential oil had inhibitory effect on Staphylocuccus aureus and it can be used as a natural preservative in food industry

[Effect of zataria multiflora boiss. essential oil on enterotoxin production by staphylococcus aureus ATCC 6538]

Staphylococcal food poisoning does not result from the ingestion of S. aureus per se, but rather from enterotoxins which are pre-formed within the food. There is no report on effect of Zataria multiflora Boiss. essential oil on enterotoxin production by this microorganism. The aim of this study was to evaluate the effect of different concentrations of Zataria multiflora Boiss. essential oil on enterotoxin production by S. aureus. This study was done as a factorial model using different concentrations of EO [0, 0.005, 0.015 and 0.03%].The bacterial growth was evaluated during 43 days of incubation and enterotoxin production was analyzed using a enterotoxin assay kit. The growth of the organism was completely inhibited by the EO=0.03%. Enterotoxin production was not affected by sub-inhibitory concentration of EO at level of 0.005%, while it was significantly [p < 0.05] inhibited by increasing subinhibitory concentration of EO to 0.015%. The adverse effect of sub-inhibitory concentration of Zataria multiflora Boiss. EO on enterotoxin production by S. aureus, demonstrated in this study, suggests the potential application of this EO as a natural antimicrobial in foods

[Effects of zataria multiflora boiss. essential oil on aspergillus flavus]

Molds are important spoiler of food material and have potential of mycotoxin production. The adverse side effects of chemical preservatives have caused that research focused on use of naturally occurring compound, especially essential oils [EOs], for inhibition of mold growth. Essential oils are natural compounds containing terpenic mixtures that have antimicrobial and antioxidant properties. Zataria multifloro Boiss., a domestic aromatic plant of Iran, has different effect such as antispasmodic and antibacterial. In this study effect of Z. multiflora Boiss. Essential oil on growth and spore production by Aspergillus flavus and its morphological alteration action were investigated. After extraction of essential oil with steam distillation method, it was analyzed by GC-MS. Evaluation of essential oil effect on growth and spore production carried out by agar dilution method. For SEM evaluation, mold cultured on PDA was fixed with osmium tetroxide and blocks of agar were coated with gold and observed by scanning electron microscope. Effect of EO on growth and spore production by A. flavus was significant in all concentrations studied. MIC and MFC values were 400 and 1000 ppm, respectively. SEM analysis showed excessive sporulation of mold culture in absence of EO while sporulation of culture containing EO was very sparse. Morphological changes such as irregular surface with many folds and distortion of hyphae were seen in cultures treated with EO. Inhibitory effect of Z. multiflora Boiss. Essential oil demonstrated in this study candidate this EO as a substitution of chemical preservatives