Sub-inhibitory stress with essential oil affects enterotoxins production and essential oil susceptibility in Staphylococcus aureus

Fourteen wild strains of Staphylococcus aureus positive for gene sea were tested for enterotoxins production and the minimum inhibitory concentration of Leptospermum scoparium, Origanum majorana, Origanum vulgare, Satureja montana and Thymus vulgaris essential oils (EOs) were determined. After this trial, bacteria stressed with sub-inhibitory concentration of each EO were tested for enterotoxins production by an immunoenzymatic assay and resistance to the same EO. Oregano oil exhibited the highest antibacterial activity followed by manuka and thyme oils. After the exposure to a sub-inhibitory concentration of EOs, strains displayed an increased sensitivity in more than 95% of the cases. After treatment with oregano and marjoram EOs, few strains showed a modified enterotoxins production, while 43% of the strains were no longer able to produce enterotoxins after treatment with manuka EO. The results obtained in this study highlight that exposure to sub-inhibitory concentration of EO modifies strains enterotoxins production and EOs susceptibility profile.     

Comparison of the oxidative stability of soybean and sunflower oils enriched with herbal plant extracts

The present study was conducted to determine and compare the oxidative stability of soybean and sunflower oils using differential scanning calorimetry (DSC). These edible oils were enriched with marjoram (Origanum majorana L.), thyme (Thymus vulgaris L.), and oregano (Origanum vulgare L.) extracts at three different concentrations and synthetic antioxidant (BHA). The fatty acid composition of studied oils was determined by gas chromatography mass spectrometry to evaluate the content of unsaturated fatty acids that are sensitive to oxidation process. Oil samples were heated in the DSC at different heating rates (4.0, 7.5, 10.0, 12.5, and 15.0 °C min^?1) and oxidation kinetic parameters (activation energy, pre-exponential factor, and oxidation rate constant) were calculated. The results showed that the oxidative stability of sunflower oil samples enriched with oregano extracts and soybean oil supplemented with thyme extracts was improved compared to samples without the addition of herbal plant extracts and the synthetic antioxidant.     

Antibacterial Effects of Essential Oils of Seven Medicinal-Aromatic Plants Against the Fish Pathogen Aeromonas veronii bv. sobria: To Blend or Not to Blend?

Despite progress achieved, there is limited available information about the antibacterial activity of constituents of essential oils (EOs) from different medicinal-aromatic plants (MAPs) against fish pathogens and the complex interactions of blended EOs thereof. The present study aimed to investigate possible synergistic antimicrobial effects of EOs from seven Greek MAPs with strong potential against Aeromonas veronii bv. sobria, a fish pathogen associated with aquaculture disease outbreaks. The main objective was to evaluate whether blending of these EOs can lead to increased antimicrobial activity against the specific microorganism. A total of 127 combinations of EOs were prepared and their effect on A. veronii bv. sobria growth was tested in vitro. We examined both the inhibitory and bactericidal activities of the individual EOs and compared them to those of the blended EOs. The vast majority of the investigated combinations exhibited significant synergistic and additive effects, while antagonistic effects were evident only in a few cases, such as the mixtures containing EOs from rosemary, lemon balm and pennyroyal. The combination of EOs from Greek oregano and wild carrot, as well as the combinations of those two with Spanish oregano or savoury were the most promising ones. Overall, Greek oregano, savoury and Spanish oregano EOs were the most effective ones when applied either in pure form or blended with other EOs.     

The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.     

Comparison of different extraction methods for the determination of essential oils and related compounds from aromatic plants and optimization of solid-phase microextraction/gas chromatography

Different extraction methods for the subsequent gas chromatographic determination of the composition of essential oils and related compounds from marjoram (Origanum majorana L.), caraway (Carum carvi L.), sage (Salvia officinalis L.), and thyme (Thymus vulgaris L.) have been compared. The comparison was also discussed with regard to transformation processes of genuine compounds, particularly in terms of expenditure of time. Hydrodistillation is the method of choice for the determination of the essential oil content of plants. For investigating the composition of genuine essential oils and related, aroma-active compounds, hydrodistillation is not very useful, because of discrimination and transformation processes due to high temperatures and acidic conditions. With cold solvent extraction, accelerated solvent extraction, and supercritical fluid extraction, discrimination of high and non-volatile aroma-active components as well as transformation processes can be diminished, but non-aroma-active fats, waxes, or pigments are often extracted, too. As solid-phase microextraction is a solvent-free fully automizable sample preparation technique, this was the most sparing to sensitive components and the most time-saving method for the rapid determination of the aroma compounds composition in marjoram, caraway, sage, and thyme. Finally, solid-phase microextraction could be successfully optimized for the extraction of the aroma components from the plants for their subsequent gas chromatographic determination.     

Determination of phenolic compounds in medicinal plants from the Lamiaceae family

A procedure for the determination of Phenolic compounds in extracts from the medicinal plants of the Lamiaceae family—garden sage (Salvia officinalis L.), creeping thyme (Thymus serpyllum L.), wild marjoram (Origanum vulgare L.), and common balm (Melissa officinalis L.)—obtained under different extraction conditions was developed. The identification of the extracted compounds was performed and their qualitative and quantitative composition was established by HPLC with diode array and mass-spectrometric detection with consideration for the obtained characteristics of the standard samples of individual components. The test samples of medicinal herbs contained caffeic acid (0.19–0.62 mg/g) and rosmaric acid (4–23 mg/g); the highest rosmaric acid content (23 mg/g) was found in wild marjoram, and the lowest content (4 mg/g), in creeping thyme. The extracts of wild marjoram contained the greatest amounts of Phenolic compounds; rosmaric acid and luteolin-7-O-β-D-glucuronide were major components, whereas protocatechuic, 3-O-caffeoylquinic, and caffeic acids were minor components.     

Influence of Agronomic Practice on Total Phenols,Carotenoids, Chlorophylls Content,and Biological Activities in Dry Herbs Water Macerates

Oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) have long been known for their organoleptic properties. Both plants are widely used in cuisine worldwide in fresh and dried form and as a pharmaceutical raw material. The study aimed to assess if the type of cultivation influenced chosen chemical parameters (total polyphenols by Folin-Ciocalteu method; carotenoids and chlorophyll content by Lichtenthaler method), antimicrobial activity (with chosen reference microbial strains) and shaped cytotoxicity (with L929 mouse fibroblasts cell line) in water macerates of dry oregano and thyme. Polyphenols content and antimicrobial activity were higher in water macerates obtained from conventional cultivation (independently from herb species), unlike the pigments in a higher amount in macerates from organic herbs cultivation. Among all tested macerates stronger antimicrobial properties (effective in inhibiting the growth of Pseudomonas aeruginosa, Bacillus cereus and Salmonella enteritidis) and higher cytotoxicity (abilities to diminish the growth of L929 fibroblasts cytotoxicity) characterized the conventionally cultivated thyme macerate.     

Chemical Composition,Enantiomeric Distribution,Antimicrobial and Antioxidant Activities of Origanum majorana L. Essential Oil from Nepal

This study was conducted to examine the chemical constituents of Origanum majorana L. essential oils (EOs) that originate in Nepal, as well as their biological activities, antioxidant properties, and enantiomeric compositions. The EOs were extracted by the hydro-distillation method using a Clevenger-type apparatus and their chemical compositions were determined through gas chromatography and mass spectrometry (GC-MS). Chiral GC-MS was used to evaluate the enantiomeric compositions of EOs. The minimum inhibitory concentrations (MICs) of the essential oils were determined by the micro-broth dilution method, and the antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl scavenging assay and ferric-reducing antioxidant power (FRAP). GC-MS analysis showed the presence of 50 and 41 compounds in the EO samples, (S₁) and (S₂), respectively, representing the Kathmandu and Bhaktapur districts. The oxygenated monoterpenoids, along with terpinen-4-ol, were predominant constituents in both EO samples. However, the EOs from two locations showed some variations in their major components. The chiral terpenoids for two EO samples of marjoram have also been reported in this study in an elaborative way for the first time in accordance with the literature review. A hierarchical cluster analysis based on the compositions of EOs with 50 compositions reported in the literature revealed at least 5 different chemotypes of marjoram oil. The antioxidant activity for the sample (S₂) was found to be relatively moderate, with an IC₅₀ value of 225.61 ± 0.05 μg/mL and an EC₅₀ value of 372.72 ± 0.84 µg/mL, as compared to the standard used. Furthermore, with an MIC value of 78.1 µg/mL, the EO from sample (S₂) demonstrated effective antifungal activity against Aspergillus niger and Candida albicans. Moreover, both samples displayed considerable antimicrobial activity. The results suggest that EOs of Origanum majorana possess some noteworthy antimicrobial properties as well as antioxidant activity, and hence can be used as a natural preservative ingredient in the food and pharmaceutical industries.     

Essential Oils of Seven Lamiaceae Plants and Their Antioxidant Capacity

Oxidative stress has been reported as a cause of many diseases like Parkinson′s, Alzheimer′s, cardiovascular disease, and diabetes. Oxidative stress can also lead to cancer formation by promoting tumor development and progression. Antioxidants derived from Lamiaceae plants play an important role in natural medicine, pharmacology, cosmetology, and aromatherapy. Herein, we examine the antioxidative capacity of essential oils from seven aromatic Lamiaceae plants against the synthetic radicals DPPH and ABTS. Among the essential oils analyzed, the most robust scavenging capacities were found in mixtures of volatile compounds from thyme and savory. The scavenging activity of tested EOs against the ABTS radical was clearly higher than activity towards DPPH. Analysis of essential oils with weaker antioxidant activity has shown that volatile compounds from marjoram, sage, and hyssop were more active than EOs from lavender and mint. It can be suggested that the potent antioxidant capacity of thyme (Thymus vulgaris) and savory (Satyreja hortensis) are related to a high level of phenolic constituents, such as thymol and carvacrol. On the other hand, the elevated antioxidative power of marjoram, sage, and hyssop essential oils may also be due to their terpinene, o-cymene, terpinolene, and terpinen-4-ol constituents. Although non-phenolic components are less active than thymol or carvacrol, they may affect antioxidant capacity synergistically.     

Comparative identification of irradiated herbs by the methods of electron paramagnetic resonance and thermoluminescence

Non irradiated and γ-irradiated dry herbs savoury (Savoury), wild thyme (Thymus serpollorium) and marjoram (Origanum) with absorbed dose of 8 kGy have been investigated by the methods of elecrtron paramagnetic resonance (EPR) and thermoluminescence (TL). Non-irradiated herbs exhibit only one weak siglet EPR signal whereas in irradiated samples its intensity increase and in addition two satelite lines are recorded. This triplet EPR spectrum is attributed to cellulose free radical generated by irradiation. It has been found that upon keeping the samples under the normal stock conditions the life-time of the cellulose free radical in the examined samples is ∼60–80 days. Thus the conclusion has been made that the presence of the EPR signal of cellulose free radical is unambiguous indication that the sample under study has been irradiated but its absence can not be considered as the opposite evidence. In the case when EPR signal was absent the method of TL has been used to give the final decision about the previous radiation treatment of the sample.     

Optimization of carvacrol,rosmarinic, oleanolic and ursolic acid extraction from oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.)

The aim of our study was to increase the extraction efficiency of carvacrol, rosmarinic, oleanolic and ursolic acid from the different species of oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.). Various extraction methods (ultrasound-assisted, heat-reflux, continuous stirring, maceration, percolation) and extraction conditions (different solvent, material:solvent ratio, extraction temperature, extraction time) were used, and the active substances were determined by HPLC. The lowest content of carvacrol, rosmarinic, oleanolic and ursolic acid was obtained by percolation. During heat-reflux extraction, the content of active substances depended on the solvent used: ethanol/non-aqueous solvent (glycerol or propylene glycol) mixture was more effective compared with ethanol alone. The results showed that for each species of oregano the most optimal extraction method should be selected to maximize the content of biologically active substances in the extracts.     

Essential Oils as In Vitro Ruminal Fermentation Manipulators to Mitigate Methane Emission by Beef Cattle Grazing Tropical Grasses

There is increasing pressure to identify natural feed additives to mitigate methane emissions from livestock systems. Our objective was to investigate the effects of essential oils (EO) extracts star anise (Illicium verum), citronella (Cymbopogon winterianus), clove bud (Eugenia caryophyllus), staigeriana eucalyptus (Eucalyptus staigeriana), globulus eucalyptus (Eucalyptus globulus), ginger (Zingiber officinale), ho wood (Cinnamomum camphora), melaleuca (Melaleuca alternifolia), oregano (Origanum vulgare) and white thyme (Thymus vulgaris) on in vitro methane emissions from four rumen-cannulated Nellore cattle grazing a tropical grass pasture as inoculum donors. The semi-automated gas production technique was used to assess total gas production, dry matter degradability, partitioning factor, ammoniacal nitrogen, short-chain fatty acids and methane production. All essential oils were tested in four doses (0, 50, 250 and 500 mg/L) in a randomized block design, arranged with four blocks, 10 treatments, four doses and two replicates. Within our study, oregano and white Thyme EO reduced net methane production at 250 mg/L, without affecting substrate degradation. Essential oils from oregano and white thyme have the potential to modify ruminal fermentation and suppress rumen methanogenesis without negative effects on feed digestibility, indicating promise as alternatives to ionophores for methane reduction in beef cattle.     

Crude extract of Origanum vulgare L. induced cell death and suppressed MAPK and PI3/Akt signaling pathways in SW13 and H295R cell lines

Oregano (Origanum vulgare L.) is a common aromatic plant used in Mediterranean and Asian Regions for treating respiratory diseases, painful menstruation, rheumatoid arthritis, etc. Recently its role as an anticancer plant has been suggested, although oregano has been never evaluated into adrenocortical tumour cell models. This study analysed for the first time the anticancer effects of a crude extract of wild mountain oregano (Origanum vulgare L.) in SW13 and H295R cell lines. The crude extract was characterised by GC/MS and the toxic effects of oregano were first analysed by brine shrimp lethality assay. Our findings demonstrated that oregano decreased cell viability, survival, modified cell cycle and induced cell death (through necrotic process) and that the effects can be attributed to a blockade of MAPK and PI3 K/Akt pathways. These results suggest that oregano extract exerts anticancer activities in adrenocortical tumour cell lines, providing evidence for further research in higher models.     

Chemical composition,cytotoxicity, antimicrobial and antifungal activity of several essential oils

Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models.     

Capillary electrophoresis for fast detection of heterogeneous population in colistin‐resistant Gram‐negative bacteria

It has been shown that diverse strains of bacteria can be separated according to their characteristic surface properties by means of CE. We employed here this analytical technique to the study of colistin‐resistance in Gram‐negative bacteria, which involves the selection of mutants with modified outer membrane composition resulting in changes of surface cell properties. In the same way as with molecular entities, we performed firstly the validation of an ITP‐based CE method for three common pathogenic Gram‐negative bacteria namely Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Secondly, we compared the electrophoretic profiles of bacterial samples from a colistin‐susceptible clinical isolate of K. pneumoniae and from the corresponding colistin‐resistant derivative. By a simple CE run taking a few minutes, the coexistence of several bacterial subpopulations in the colistin‐resistant derivative was clearly evidenced. This work encourages further research that would allow applications of CE in clinical laboratory for a daily monitoring of bacterial population in cared patients when “last‐chance” colistin treatment is initiated against multidrug‐resistant bacteria.     

Deuterium/hydrogen ratio analysis of thymol, carvacrol, gamma-terpinene and p-cymene in thyme, savory and oregano essential oils by gas chromatography-pyrolysis-isotope ratio mass spectrometry

Isotope ratio mass spectrometry online coupled with capillary gas chromatography (GC-Py-IRMS) on column INNOWAX is used in the origin specific analysis and the authenticity control of the phenolic essential oils (EOs). Isotopic data delta(2)H(V-SMOW) of thymol and carvacrol in natural essential oils were evidently more depleted than synthetic products (from -49 to 7 per thousand for thymol and -61 per thousand for carvacrol). delta(2)H(V-SMOW) values of p-cymene, gamma-terpinene and thymol in authentic thyme oils (Thymus vulgaris L. and Thymus zygis L.) were found from -300 to -270 per thousand, from -285 to -248 per thousand and from -259 to -234 per thousand, respectively. delta(2)H(V-SMOW) values of carvacrol and p-cymene in authentic oregano oils (Origanum heracleoticum L., Coridothymus capitatus L. and Origanum compactum L.) varied from -223 to -193 per thousand and from -284 to -259 per thousand, respectively. For authentic Satureja montana subsp. montana essential oils, the mean delta(2)H(V-SMOW) value for aromatic compounds were found to be the following: gamma-terpinene -273 per thousand (SD=4.6 per thousand) and p-cymene -283 per thousand (SD=3.0 per thousand), thymol -245 per thousand (SD=1.8 per thousand) and carvacrol -226 per thousand (SD=1.7 per thousand). In addition, p-cymene was previously found as a precursor of the biosynthesis of thymol and carvacrol in thyme oil, thus, we considered p-cymene as an endogenous reference compound (ERC) for D/H ratio analysis. The isotopic fractionation factors alpha(thymol/p-cymene)=1.05 and alpha(carvacrol/p-cymene)=1.08 were obtained and also used to control the authenticity of the phenolic EOs.     

Comparison of Origanum Essential Oil Chemical Compounds and Their Antibacterial Activity against Cronobacter sakazakii

Origanum vulgare L. (oregano) is an aromatic plant with wide applications in the food and pharmaceutical industries. Cronobacter sakazakii, which has a high detection rate in powdered infant formula, adversely impacts susceptible individuals. Oregano essential oil (OEO) is a natural antibacterial agent that can be used to fight bacterial contamination. Here, OEO chemical compounds from eight oregano varieties were analyzed by gas chromatography–mass spectrometry and their antibacterial properties were assessed. The eight OEOs were clustered into two groups and were more diverse in group 2 than in group 1. Six compounds, including p-cymene, 3-thujene, γ-terpinene, thymol, carvacrol, and caryophyllene, were shared by eight OEOs. Among the eight oregano varieties, OEOs from O. vulgare sc2 had the strongest antibacterial activity against C. sakazaki, with the inhibition zone of 18.22mm. OEOs from O. vulgare jx, O. ‘Nvying’, O. vulgare ‘Ehuang’, and O. vulgare ssp. virens were also potent. Moreover, the antibacterial activity of OEOs was positively correlated with the relative content of thymol. As the main OEO antibacterial compound, thymol affected the normal growth and metabolism of C. sakazakii cells by destroying the bacterial membrane and decreasing the intracellular ATP concentration. Thus, in light of the antibacterial activity detected in the OEOs from the eight oregano varieties, this study provides a theoretical foundation for oregano cultivar management and development.     

Nanovesicles Loaded with Origanum onites and Satureja thymbra Essential Oils and Their Activity against Food-Borne Pathogens and Spoilage Microorganisms

Food poisoning is a common cause of illness and death in developing countries. Essential oils (EOs) could be effective and safe natural preservatives to prevent and control bacterial contamination of foods. However, their high sensitivity and strong flavor limit their application and biological effectiveness. The aim of this study was firstly the chemical analysis and the antimicrobial evaluation of the EOs of Origanum onites L. and Satureja thymbra L. obtained from Symi island (Greece), and, secondly, the formulation of propylene glycol-nanovesicles loaded with these EOs to improve their antimicrobial properties. The EOs were analyzed by GC-MS and their chemical contents are presented herein. Different nanovesicles were formulated with small average sizes, high homogeneity, and optimal ζ-potential. Microscopic observation confirmed their small and spherical shape. Antibacterial and antifungal activities of the formulated EOs were evaluated against food-borne pathogens and spoilage microorganisms compared to pure EOs. Propylene glycol-nanovesicles loaded with O. onites EO were found to be the most active formulation against all tested strains. Additionally, in vitro studies on the HaCaT cell line showed that nanovesicles encapsulated with EOs had no toxic effect. The present study revealed that both EOs can be used as alternative sanitizers and preservatives in the food industry, and that their formulation in nanovesicles can provide a suitable approach as food-grade delivery system.     

Rapid analysis of Origanum majorana L. fragrance using a nanofiber sheet,gas chromatography with mass spectrometry,and chemometrics

Headspace nanofiber sheet microextraction together with GC–MS and chemometrics resolution techniques were implemented to separate and identify the volatiles emitted by intact marjoram (Origanum majorana L.) and their relative concentrations. A novel polyaniline‐nylon‐6 nanofiber composite was applied for headspace microextraction. Characteristics such as high surface‐to‐volume ratio and π–π functional groups in polyaniline together with the NH and C=O functional groups in nylon‐6 make the polyaniline‐nylon‐6 nanofiber composite a suitable candidate for the extraction of volatiles and semivolatiles. The extracted constituents were desorbed and injected into the GC–MS system under the optimum conditions. Chemometric resolution techniques were utilized to solve the baseline offset, asymmetric peaks, and overlapped peaks problems that arise from GC–MS analysis. By means of these techniques and resolving the overlapped peak clusters, the number of identified constituents was increased to 67 compounds. The major released constituents from the intact marjoram leaves are 4‐terpineol, β‐linalool, cis‐sabinol, and trans‐geraniol.     

Anti-Biofilms’ Activity of Garlic and Thyme Essential Oils against Salmonella typhimurium

Biofilm control by essential oil (EO) application has recently increased to preclude biofilm production on foods and environmental surfaces. In this work, the anti-biofilm effects of garlic and thyme essential oils using the minimum inhibitory concentration (MIC) method against Salmonella typhimurium recovered from different abattoir samples were investigated along with the virulence genes (InvA, SdiA and Stn genes), and the antimicrobial susceptibility profile of S. typhimurium as well. The obtained results revealed that S. typhimurium contaminated abattoir samples to varying degrees. The InvA gene was investigated in all isolates, whereas the SdiA and Stn genes were observed in four and three isolates, respectively. Utilizing the disc diffusion method, S. typhimurium isolates demonstrated substantial resistance to most of the examined antibiotics with a high multiple antibiotic resistance index. S. typhimurium isolates demonstrated biofilm formation abilities to various degrees at varied temperatures levels (4 °C and 37 °C). In conclusion, the obtained samples from the research area are regarded as a potential S. typhimurium contamination source. Furthermore, garlic essential oil (GEO) has more potential to inhibit S. typhimurium biofilm at different sub-minimum inhibitory concentrations as compared to thyme essential oil (TEO). Therefore, these EOs are considered as potential natural antibacterial options that could be applied in food industry.