Use Carum copticum essential oil for controlling the Listeria monocytogenes growth in fish model system

Physicochemical, antioxidant, antibacterial and antibiofilm activity of Carum copticum essential oil nanoemulsion on Escherichia coli O157:H7 and Listeria monocytogenes

Carum copticum essential oil (CEO) is used to prevent the growth of food-borne pathogens. The Carum copticum essential oil nanoemulsion (CEON) was prepared using low energy sonication at 0, 2.50, 5.00 and 10 min based on surfactant to-oil ratio (SOR=1). Chemical composition, antimicrobial and antibiofilm properties of CEON were examined. Our data showed that the average diameter of the droplets of CEON was between 46.89 and 120.90 nm. The MICs of CEON and CEO against E. coli O157:H7 and L. monocytogenes were tested. L. monocytogenes was more sensitive than E. coli O157:H7. The sonication time and the total viable bacteria (TVC) in the study were inversely related to each other. Furthermore, CEON at the 4.00 × MIC concentration and contact time of 20 min caused 77.14% and 67.03% reduction of E. coli O157:H7 and L. monocytogenes biofilms, respectively. The antibiofilm activity of CEO was significantly lower than CEON and caused a 62.60% and 43.86% reduction of E. coli O157: H7 and L. monocytogenes biofilms, respectively. The results showed that CEON produced by low energy sonication would have a higher antibacterial efficiency than non-encapsulted essential oil.

Potential Role of Plant Extracts and Phytochemicals Against Foodborne Pathogens

Foodborne diseases are one of the major causes of morbidity and mortality, especially in low-income countries with poor sanitation and inadequate healthcare facilities. The foremost bacterial pathogens responsible for global outbreaks include Salmonella species, Campylobacter jejuni, Escherichia coli, Shigella sp., Vibrio, Listeria monocytogenes and Clostridium botulinum. Among the viral and parasitic pathogens, norovirus, hepatitis A virus, Giardia lamblia, Trichinella spiralis, Toxoplasma and Entamoeba histolytica are commonly associated with foodborne diseases. The toxins produced by Staphylococcus aureus, Bacillus cereus and Clostridium perfringens also cause these infections. The currently available therapies for these infections are associated with various limited efficacy, high cost and side-effects. There is an urgent need for effective alternative therapies for the prevention and treatment of foodborne diseases. Several plant extracts and phytochemicals were found to be highly effective to control the growth of these pathogens causing foodborne infections in in vitro systems. The present review attempts to provide comprehensive scientific information on major foodborne pathogens and the potential role of phytochemicals in the prevention and treatment of these infections. Further detailed studies are necessary to evaluate the activities of these extracts and phytochemicals along with their mechanism of action using in vivo models.

Antagonistic activity of Thymus vulgaris extracts against Vibrio species isolated from seafoods

This study examined the antibacterial activity of Thymus vulgaris on multiple antibiotic resistant (MAR) Vibrio parahaemolyticus and Vibrio fluvialis isolated from shrimps. The ethanol extract of T. vulgaris antibacterial properties was assessed using the agar diffusion method. Survival of test organisms in shrimp meat using different concentrations of T. vulgaris was done using standard method. The quantitative and qualitative phytochemical tests of T. vulgaris extract were determined. The ethanol extract had antimicrobial activities on the test organisms showing 20.00 ± 0.0 and 23.00 ± 0.0 mm zone of inhibition on V. parahaemolyticus and V. fluvialis respectively. T. vulgaris completely decreased microbial load of V. parahaemolyticus and V. fluvialis in 150 and 60 min, respectively. The phytochemical screening for the ethanol extract reported phenol, alkaloids, tannin, saponin, anthraquinone flavonoid and cardiac glycoside as 51.76, 26.60, 6.76, 54.33, 30.35 89.65 and 18.23 mg/100 g, respectively. This study reveals the antibacterial property of T. vulgaris on the MAR Vibrio species.