Anti-Listerial Effect of 4-Hydroxyphenylpropanoic Acid Esters Synthesized by Lipase-Catalyzed Esterification

Listeria monocytogenes—A Gram-positive intracellular bacteria is one of the most virulent foodborne pathogens. A common strategy used to control the growth of bacteria in food is using food additives. However, many bacterial species are resistant to food preservatives, and bacterial resistance can be natural or acquired. Therefore, there is a constant need to search for new compounds with antimicrobial properties. The purpose of the present study was to evaluate the efficiency of five (ethyl, butyl, hexyl, octyl, and decyl) esters of 4-hydroxyphenylpropanoic acid against L. monocytogenes PCM 2191. Esters were obtained in reactions catalyzed by Candida antarctica lipase B. Purified esters with structures confirmed by 1H NMR were applied to determine minimal inhibitory concentrations (MIC) using the microdilution broth method. MIC values ranged 0.0625–16 mM. The results of this study have demonstrated the potential application of 4-hydroxyphenylpropanoic acid alkyl esters in inhibiting the growth of L. monocytogenes. Octyl 4-hydroxyphenylpropanoate proved to be the best antimicrobial agent and was used in a time-kill assay with different concentrations of 1 × MIC, 4 × MIC, and 16 × MIC. Three to nine log reduction of cell number were observed compared to control medium without any antimicrobial compound after 24 h, and the possibility of using octyl 4-hydroxyphenylpropanoate in food applications is worth further investigation.

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Critical Synergistic Concentration of Lecithin Phospholipids Improves the Antimicrobial Activity of Eugenol against Escherichia coli

Applied and Environmental Microbiology ◽

10.1128/aem.01583-17 ◽

2017 ◽

Vol 83 (21) ◽

Cited By ~ 2

Author(s):

Haoshu Zhang ◽

Edward G. Dudley ◽

Federico Harte

Keyword(s):

Escherichia Coli ◽

Foodborne Pathogens ◽

Rational Design ◽

Microbial Population ◽

Critical Concentration ◽

Antimicrobial Properties ◽

Content Type ◽

E Coli ◽

Log Reduction ◽

Naturally Occurring

ABSTRACT In this study, the effect of individual lecithin phospholipids on the antimicrobial properties of eugenol against Escherichia coli C600 was investigated. We tested five major phospholipids common in soy or egg lecithin (1,2-dihexadecanoyl-sn-glycero-3-phosphocholine [DPPC], 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine [DSPC], 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine [DPPE], 1,2-dihexadecanoyl-sn-glycero-3-phosphate [sodium salt] [DPPA], and 1,2-dihexadecanoyl-sn-glycero-3-phospho-l-serine [DPPS]) and one synthetic cationic phospholipid (1,2-dioctadecanoyl-sn-glycero-3-ethylphosphocholine [18:0 EPC]). Among the six phospholipids, DPPC, DSPC, DPPE, DPPA, and the cationic 18:0 EPC showed critical synergistic concentrations that significantly improved the inactivation effect of eugenol against E. coli after 30 min of exposure. At the critical synergistic concentration, an additional ca. 0.4 to 1.9 log reduction (ca. 0.66 to 2.17 log CFU/ml reduction) in the microbial population was observed compared to eugenol-only (control) treatments (ca. 0.25 log reduction). In all cases, increasing the phospholipid amount above the critical synergistic concentration (which was different for each phospholipid) resulted in antimicrobial properties similar to those seen with the eugenol-only (control) treatments. DPPS did not affect the antimicrobial properties of eugenol at the tested concentrations. The critical synergistic concentration of phospholipids was correlated with their critical micelle concentrations (CMC). IMPORTANCE Essential oils (EOs) are naturally occurring antimicrobials, with limited use in food due to their hydrophobicity and strong aroma. Lecithin is used as a natural emulsifier to stabilize EOs in aqueous systems. We previously demonstrated that, within a narrow critical-concentration window, lecithin can synergistically enhance the antimicrobial properties of eugenol. Since lecithin is a mixture of different phospholipids, we aimed to identify which phospholipids are crucial for the observed synergistic effect. This research studied the bioactivity of lecithin phospholipids, contributing to a rational design in using lecithin to effectively control foodborne pathogens in foods.

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ANTIBACTERIAL ACTIVITY OF FRESH ONION AND GARLIC JUICES

Journal of Science and Arts ◽

10.46939/j.sci.arts-20.3-b02 ◽

2020 ◽

Vol 20 (3) ◽

pp. 705-712

Author(s):

LUCIANA TEODORA ROTARU ◽

MARIUS NOVAC ◽

OANA NICOLAESCU

Keyword(s):

Bacterial Resistance ◽

Antibacterial Effect ◽

Bacterial Species ◽

Antimicrobial Properties ◽

Chemotherapeutic Agents ◽

Active Components ◽

Docking Method ◽

Therapeutic Properties ◽

Species Being

Herbal extracts with antimicrobial potential represent an important research directive, in the current medical world, aiming to isolate active components, to develop new chemotherapeutic agents with applicability in the treatment or use as adjuvant therapy in infectious states. Antimicrobial properties of plants are conferred by their ability to synthesize certain secondary metabolites with relatively complex structures. The last century has been marked by sustained efforts to search for new natural compounds with antibacterial therapeutic properties, due to the gradual reduction in the number of effective allopathic antibiotics and the toxic effects of antibiotic residues. Numerous in vitro studies have shown that plants have antibacterial efficacy, discovering the importance of little-studied natural resources in this regard, as being effective in fighting against bacterial resistance and destroying bacterial agents. In this study, the antibacterial effect of the fresh onion and garlic juice was compared to the antibiotics of choice, using the diffusimetric agar method. Both plant products tested have antibacterial effect, the bacterial species being classified as sensitive to their action. The molecular docking method helps us to see the type of interaction between ligands and targets, allicin having no common binding site with antibiotics of choice.

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Antimicrobial effect of tea polyphenols against foodborne pathogens

Journal of Food Protection ◽

10.4315/jfp-21-043 ◽

2021 ◽

Author(s):

Qianling Zhang ◽

Jin Zhang ◽

Jiaqi Zhang ◽

Duo Xu ◽

Yajuan Li ◽

...

Keyword(s):

Foodborne Pathogens ◽

Food Additives ◽

Food Contamination ◽

Antimicrobial Effect ◽

Tea Polyphenols ◽

Public Health Issue ◽

Chemical Components ◽

Global Public Health ◽

Food Preservatives ◽

Depth Study

In recent years, science and technology have developed to a considerable level. However, food contamination by food-borne pathogens is still widespread in many countries around the world, and food safety is a major global public health issue. Therefore, novel preservatives that can guarantee safer food are high in demand. Contrary to artificial food preservatives, tea polyphenols (TP) are getting wide attention as food additives for being "green", "safe" and "healthy". The sources of TP are wide, and the purification technology is sophisticated. Compared with other natural antibacterial agents, its antibacterial effect is more stable. It is an excellent natural antibacterial agent. Here, this review systematically summarizes the important chemical components of TP and discusses their antibacterial mechanisms against various foodborne pathogens. In addition, the potential application areas of TP are also discussed. It can provide a theoretical basis for the in-depth study of TP.

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Improvement of the Antimicrobial Activity of Oregano Oil by Encapsulation in Chitosan–Alginate Nanoparticles

Molecules ◽

10.3390/molecules26227017 ◽

2021 ◽

Vol 26 (22) ◽

pp. 7017

Author(s):

Krassimira Yoncheva ◽

Niko Benbassat ◽

Maya M. Zaharieva ◽

Lyudmila Dimitrova ◽

Alexander Kroumov ◽

...

Keyword(s):

Antimicrobial Activity ◽

Water Solubility ◽

Food Additives ◽

Antimicrobial Properties ◽

Aqueous Dispersion ◽

In Vitro Cytotoxicity ◽

Application Site ◽

Minimal Inhibitory Concentrations ◽

Oregano Oil

Oregano oil (OrO) possesses well-pronounced antimicrobial properties but its application is limited due to low water solubility and possible instability. The aim of this study was to evaluate the possibility to incorporate OrO in an aqueous dispersion of chitosan–alginate nanoparticles and how this will affect its antimicrobial activity. The encapsulation of OrO was performed by emulsification and consequent electrostatic gelation of both polysaccharides. OrO-loaded nanoparticles (OrO-NP) have small size (320 nm) and negative charge (−25 mV). The data from FTIR spectroscopy and XRD analyses reveal successful encapsulation of the oil into the nanoparticles. The results of thermogravimetry suggest improved thermal stability of the encapsulated oil. The minimal inhibitory concentrations of OrO-NP determined on a panel of Gram-positive and Gram-negative pathogens (ISO 20776-1:2006) are 4–32-fold lower than those of OrO. OrO-NP inhibit the respiratory activity of the bacteria (MTT assay) to a lower extent than OrO; however, the minimal bactericidal concentrations still remain significantly lower. OrO-NP exhibit significantly lower in vitro cytotoxicity than pure OrO on the HaCaT cell line as determined by ISO 10993-5:2009. The irritation test (ISO 10993-10) shows no signs of irritation or edema on the application site. In conclusion, the nanodelivery system of oregano oil possesses strong antimicrobial activity and is promising for development of food additives.

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Antimycotic Effects of 11 Essential Oil Components and Their Combinations on 13 Food Spoilage Yeasts and Molds

Journal of Fungi ◽

10.3390/jof7100872 ◽

2021 ◽

Vol 7 (10) ◽

pp. 872

Author(s):

Laura Nißl ◽

Florian Westhaeuser ◽

Matthias Noll

Keyword(s):

Food Safety ◽

Foodborne Pathogens ◽

Food Additives ◽

Total Cell ◽

Food Spoilage ◽

Minimal Inhibitory Concentrations ◽

Cell Numbers ◽

Microdilution Method ◽

Spoilage Yeasts ◽

Yeasts And Molds

Food safety is important to reduce food spoilage microorganisms and foodborne pathogens. However, food safety is challenging, as customers’ demand for natural preservatives is increasing. Essential oils (EOs) and their components (EOCs) are alternative antibacterial and antimycotic food additives. In this study, the minimal inhibitory concentrations (MIC) of 11 different EOCs against 13 food spoilage molds and yeasts were investigated via the microdilution method. Cinnamaldehyde (CA) revealed the lowest MIC for all tested strains and all EOCs (32.81–328.1 µg ml−1). However, CA is organoleptic and was therefore combined with other EOCs via the checkerboard method. Overall, 27 out of 91 combinations showed a synergistic effect, and both respective EOC concentrations could be reduced by maintaining MIC. Thereby, the combination with citral or citronellal showed promising results. The concentration-dependent effect of CA was studied in further detail on Saccharomyces cerevisiae, with CA causing delayed growth-kinetics and reduced total cell numbers. In addition, flow cytometric measurements combined with live–dead staining indicate the fungicidal effect of CA, due to decreasing total cell numbers and increasing relative amount of propidium iodide-positive cells. In this study, we demonstrated that CA is a potent candidate for the use as a natural preservative against food-relevant mold and yeasts showing fungistatic and fungicidal effects. Therefore, CA and EOC combinations with respective lower EOC concentrations reduce organoleptic reservations, which ease their application in the food industry.

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Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200730144536 ◽

2020 ◽

Vol 21 ◽

Author(s):

Nilushi Indika Bamunu Arachchige ◽

Fazlurrahman Khan ◽

Young-Mog Kim

Keyword(s):

Secondary Metabolites ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Bacterial Species ◽

Antimicrobial Properties ◽

Antimicrobial Effect ◽

Cost Effective ◽

Resistance Mechanisms ◽

Marine Organisms ◽

Antimicrobial Compounds

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.

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Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields

Nanomaterials ◽

10.3390/nano11020342 ◽

2021 ◽

Vol 11 (2) ◽

pp. 342

Author(s):

Vitalij Novickij ◽

Ramunė Stanevičienė ◽

Rūta Gruškienė ◽

Kazimieras Badokas ◽

Juliana Lukša ◽

...

Keyword(s):

Magnetic Fields ◽

Foodborne Pathogens ◽

Morphological Changes ◽

Foodborne Pathogen ◽

Cellular Damage ◽

Suitable Model ◽

Log Reduction ◽

Invasive Infections ◽

Alternating Magnetic Fields ◽

Inactivation Of Bacteria

Foodborne pathogens are frequently associated with risks and outbreaks of many diseases; therefore, food safety and processing remain a priority to control and minimize these risks. In this work, nisin-loaded magnetic nanoparticles were used and activated by alternating 10 and 125 mT (peak to peak) magnetic fields (AMFs) for biocontrol of bacteria Listeria innocua, a suitable model to study the inactivation of common foodborne pathogen L. monocytogenes. It was shown that L. innocua features high resistance to nisin-based bioactive nanoparticles, however, application of AMFs (15 and 30 min exposure) significantly potentiates the treatment resulting in considerable log reduction of viable cells. The morphological changes and the resulting cellular damage, which was induced by the synergistic treatment, was confirmed using scanning electron microscopy. The thermal effects were also estimated in the study. The results are useful for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections. The proposed methodology is a contactless alternative to the currently established pulsed-electric field-based treatment in food processing.

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Valorization of Sicanaodorifera (Vell.) Naudin Epicarp as a Source of Bioactive Compounds: Chemical Characterization and Evaluation of Its Bioactive Properties

Foods ◽

10.3390/foods10040700 ◽

2021 ◽

Vol 10 (4) ◽

pp. 700

Author(s):

Bianca R. Albuquerque ◽

Maria Inês Dias ◽

Carla Pereira ◽

Jovana Petrović ◽

Marina Soković ◽

...

Keyword(s):

Phenolic Compounds ◽

Bioactive Compounds ◽

Food Additives ◽

Chemical Characterization ◽

Dry Weight ◽

Bioactive Molecules ◽

High Concentration ◽

Minimal Inhibitory Concentrations ◽

Antibacterial And Antifungal Activities ◽

Antibacterial And Antifungal

Fruit bio-residues can be interesting for the recovery of bioactive molecules, such as phenolic compounds, tocopherols, vitamins, among others. These compounds can be targeted at the food industry and used for the development of functional foods or as food additives. In some cases, fruit epicarps are converted into by-products with non-commercial value, and generally, these fruit parts have a higher content in bioactive compounds than the fruit pulp. From this perspective, S. odorifera, a Brazilian fruit, has an inedible epicarp that could be explored to obtain biological compounds. Therefore, the aims of this study were to evaluate the chemical composition and the antioxidant, anti-proliferative, anti-inflammatory, and antimicrobial bioactivities of this by-product. S. odorifera epicarp showed a total of four organic acids, four phenolic compounds, highlighting the high concentration of anthocyanins (24 ± 1 mg/g dry weight (dw)) and high content of tocopherols (366 ± 2 mg/100 g dw). The hydroethanolic extract showed considerable antioxidant activity (EC50 values of 48.2 ± 0.5 and 27 ± 1 µg/mL for TBARS and OxHLIA assays, respectively), as also antibacterial and antifungal activities (minimal inhibitory concentrations (MICs) ≤ 2.2 mg/mL). The results obtained in this study suggest that Sicana odorifera epicarp represents a reliable option for the development of novel natural-based colorants with functional/bioactive proprieties.

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The Use of Bacteriophages in the Poultry Industry

Animals ◽

10.3390/ani10050872 ◽

2020 ◽

Vol 10 (5) ◽

pp. 872 ◽

Cited By ~ 6

Author(s):

Katarzyna Żbikowska ◽

Monika Michalczuk ◽

Beata Dolka

Keyword(s):

Foodborne Pathogens ◽

Pathogenic Bacteria ◽

Bacterial Resistance ◽

Health And Safety ◽

Legal Framework ◽

Multidrug Resistant ◽

Poultry Production ◽

Salmonella Spp ◽

Food Contact Surfaces ◽

Public Health And Safety

The emergence of multidrug-resistant infections and antibiotic failures have raised concerns over human and veterinary medicine worldwide. Poultry production has had to confront the problems of an alarming increase in bacterial resistance, including zoonotic pathogens. According to the European Food Safety Authority (EFSA), campylobacteriosis and salmonellosis have been the most frequently reported human foodborne diseases linked to poultry. This situation has strongly stimulated a renewal of scientists’ interest in bacteriophages (phages) since the beginning of the 21st century. Bacteriophages are the viruses of bacteria. They are abundant in nature, and accompany bacteria in each environment they colonize, including human microbiota. In this review, we focused on the use of bacteriophages as therapeutic agents to treat infections and reduce counts of pathogenic bacteria in poultry, as biocontrol agents to eliminate foodborne pathogens on/in food, and also as disinfectants to reduce contamination on food-contact surfaces or poultry carcasses in industrial conditions. Most of the phage-based products are targeted against the main foodborne pathogens, such as Campylobacter jejuni, Salmonella spp., Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Clostridium perfringens. Phages are currently addressed at all stages of the poultry production "from farm to fork", however, their implementation into live birds and food products still provokes discussions especially in the context of the current legal framework, limitations, as well as public health and safety.

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Salmonella Heidelberg Strain Responses to Essential Oil Components

Journal of Food Research ◽

10.5539/jfr.v4n5p73 ◽

2015 ◽

Vol 4 (5) ◽

pp. 73 ◽

Cited By ~ 2

Author(s):

Juliany Rivera Calo ◽

Christopher A. Baker ◽

Si Hong Park ◽

Steven C. Ricke

Keyword(s):

Foodborne Pathogens ◽

Food Production ◽

Antimicrobial Agents ◽

Health Concern ◽

Orange Oil ◽

Major Health ◽

Minimal Inhibitory Concentrations ◽

Color Changes ◽

Different Sources ◽

Strain Responses

Salmonella are one of the more prominent foodborne pathogens that represent a major health risk to humans. Salmonella serovar Heidelberg strains are increasingly becoming an important public health concern, since they have been identified as one of the primary Salmonella serovars responsible for human outbreaks. Over the years, Salmonella Heidelberg isolates have exhibited higher rates of resistance to multiple antimicrobial agents compared to other Salmonella serovars. Essential oils (EOs) have been widely used as alternatives to chemical-based antimicrobials. In the current research, five EOs were screened to determine their antimicrobial activity against 15 S. Heidelberg strains from different sources. Oils tested were R(+)-limonene, orange terpenes, cold compressed orange oil, trans-cinnamaldehyde and carvacrol. EOs were stabilized in nutrient broth by adding 0.15% (w/v) agar. Tube dilution assays and minimal inhibitory concentrations (MIC) were determined by observing color changes in samples during exposure to EOs. Carvacrol and trans-cinnamaldehyde completely inhibited the growth of S. Heidelberg strains, while R(+)-limonene and orange terpenes did not show any inhibitory activity against the strains tested. Cold compressed orange oil only inhibited growth of two of the strains exhibiting an MIC of 1%. All S. Heidelberg isolates evaluated exhibited similar responses to the respective EOs. The use of all natural antimicrobials such as specific EOs offers the potential to limit the majority of S. Heidelberg isolates that may occur in food production.

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