Antibacterial Activity of Carum copticum Essential Oil Against Escherichia Coli O157:H7 in Meat: Stx Genes Expression

Abstract

This work were aimed to (a) determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Carum copticum essential oil (EO) against Escherichia. coli O157:H7 in vitro Trypticase Soy Broth, (TSB) and in ground beef; (b) evaluation of the effect of sub-inhibitory concentrations (sub-MICs) of EO on the growth of bacterium in TSB over 72 h (at 35 °C) and ground beef over 9 days (at 4 °C); and (c) investigation of gene expression involved in Shiga toxins production using relative quantitative real-time PCR method. The MIC in broth and ground beef medium were determined as 0.05 (v/v) and 1.75 % (v/w), respectively. In comparison with control cultures, the EO concentration of 0.03 % in broth caused reduction of colony counting as 1.93, 1.79, and 2.62 log10 CFU ml(-1) after 24, 48, and 72 h at 35 °C, and similarly EO (0.75 %) in ground beef resulted to reduction of colony counting as 1.03, 0.92, 1.48, and 2.12 log10 CFU g (-1) after 2, 5, 7, and 9 days at 4 °C, respectively. An increase and decrease in gene expression were observed as result of EO addition (0.03 %) to broth and (0.5 %) to ground beef was noticed, respectively.

The Role of Essential Oils against Pathogenic Escherichia coli in Food Products

“…However, the expression of genes related to cell-to-cell communication and Stx synthesis was not influenced by both clove EO and eugenol. In a similar way, the experiment carried out by Mahmoudzadeh [32] did not obtain down-regulation of stx1A and stx2A in the culture medium, which was in fact up-regulated by 0.03%.…”

“…To the best of our knowledge, only a single study explored the influence of EOs in the expression of genes related to virulence in food systems [32]. In this experiment, ground beef was inoculated with E. coli O157:H7 (10 9 CFU/g meat) and the inhibitory effect of Carum copticum EO in the expression of stx1A and stx2A genes was observed on days 2 (0.5 MIC of EO) and 5 (0.75 MIC of EO) of storage.…”

“…In this condition, it is possible to clarify and understand the antipathogenic mechanisms of EOs. It is relevant mentioning that recent studies characterized the MIC value of EOs against pathogenic E. coli to be in the range in the range of 0.025 and 0.1% [ 29 , 30 , 31 , 32 ]. The inhibition of toxin synthesis when pathogenic E. coli are exposed to EOs is presented in Table 1 .…”

Antimicrobial, Antioxidant, and Immunomodulatory Properties of Essential Oils: A Systematic Review

“…Enteromorpha linza , Baccharis dracunculifolia , Syringa yunnanensis , Senecio nutans , basil, chamomile blue, oregane, thyme, tea tree oil, Carum copticum , and Xanthium strumarium L. EOs have also been described for their anti-microorganism effects against several bacteria, fungi, and even some pathogens, such as Vibrio cholerae . Specifically, Enteromorpha linza EO is effective against B. cereus and S. aureus [54], Baccharis dracunculifolia EO is active against S. aureus and E. coli [55], Senecio nutans EO is effective against V. cholerae [53], Syringa yunnanensis EO is effective against S. aureus [72], Carum copticum EO is capable of reducing the growth of E. coli O157:H7 [44], and Xanthium strumarium L. EO is also effective against S. aureus , B. subtilis , K. pneumoniae , P. aeruginosa , C. albicans , and A. niger [63]. In contrast, basil, chamomile blue, oregane, thyme, and tea tree oil EOs were not sufficiently effective against A. baumannii , E. coli , K. pneumoniae , and P. aeruginosa [58].…”

Antimicrobial and antioxidant properties of burgers with quinoa peptide‐loaded nanoliposomes

“…Herbal extracts and essences, as well as natural compounds, with some antibacterial properties, are used as food preservatives (Mahmoudzadeh et al, , ; Pateiro et al, ; Pilevar et al, ). In this regard, the plant‐based compounds such as cinnamon (Ojagh, Rezaei, Razavi, & Hosseini, ), curry, mint (Biswas, Chatli, & Sahoo, ), oregano, rosemary (Makri, ), and green tea essential oils (Hashemi & Mousavi Khaneghah, ) successfully were employed in controlling of microbial growth and lipid oxidation (Perumalla & Hettiarachchy, ; Siripatrawan & Noipha, ).…”