Growth Of Foodborne Pathogens Research Articles

Single and combined effects of oregano leaf and clove oils on the reduction of salmonella enteritidis on chicken egg shells

Table eggs are versatile foodstuffs used in various food products. Eggs are often consumed or incorporated into other food products to enhance taste and nutrition and act as an emulsifying agent. Too often the consumption of contaminated eggs leads to foodborne illnesses in people. When whole eggs or egg products come into contact with contaminated surfaces or other contaminated eggs, pathogens can spread from one egg to another. Research has been conducted to uncover ways to protect whole eggs and their products from contamination by coating the egg’s exterior with edible coatings. Mineral oil, among other edible oils, is one such oil shown to be effective in reducing the bacteria in eggs when applied to the egg’s exterior. With the average consumer becoming more aware of the chemicals used in the preservation of food, some researchers have started to explore more natural solutions to minimize the contamination of food products. The use of essential oils to prevent contamination has been studied and analyzed for their antimicrobial properties in the inhibition of the growth of foodborne pathogens. The oils used in this current study are Oregano and Clove Oil. Both oils used individually and combined compared to a positive control showed no differences (p > 0.05). Interestingly, when the oils were combined 1:1 there was a difference of 0.66 log in the survival bacterial counts compared to the positive control. However, this difference was also not significant (p > 0.05).

The effectiveness of garlic extracts on biogenic amine formation by foodborne pathogens and fish spoilage bacteria

SummaryImpacts of aqueous and ethanolic extracts of garlic were investigated in suppressing bacterial growth and biogenic amine (BA) formation by selected foodborne pathogens (Candida albicans, Salmonella paratyphi A, Escherichia coli and Staphylococcus aureus) and fish spoilage bacteria (Enterococcus faecalis, Photobacterium damselae and Pseudomonas luteola). The spread‐plate method was used to monitor bacterial growth in histidine decarboxylase broth (HDB), whereas the rapid high‐performance liquid chromatographic (HPLC) method was used for BA analysis. Bacterial growth and their ammonia and BA production were monitored using HDB. The results showed that bacterial growth on HDB was in the range from 9.13, for P. luteola, to 9.54 log CFU (colony‐forming units) mL−1, for S. aureus and C. albicans. The presence of garlic extracts in HDB resulted considerably in lowering bacterial growth and BA formation (P < 0.05). The highest inhibitory activities of ethanolic and water garlic extracts were obtained for Gram‐positive S. aureus with 1.4 and 1.5 logarithmic reduction on bacterial growth, followed by Gram‐negative Salmonella Paratyphi A and E. coli. Application of garlic extracts, mainly ethanolic ones, showed a significant inhibitory effect on bacterial ammonia production, with 4‐100‐fold lower ammonia accumulation (P < 0.05). Bacteria produced all tested BAs, mainly dopamine, agmatine and tryptamine. The highest levels of histamine and tyramine (61.99 and 36.45 mg L−1) were produced by S. aureus. In the presence of aqueous or ethanolic garlic extracts, putrescine production by E. faecalis was around 110‐fold lower than that of the control group. Results revealed that both garlic extracts are potent antimicrobials that can control the growth of foodborne pathogens and their harmful BA formation.

The effect of a 3D-modeled pyramidal packing shape on the growth of foodborne pathogens inoculated in ribeye-lion at dynamic room temperatures.

The effect of a 3D-modeled pyramidal packing shape on the growth of foodborne pathogens inoculated in ribeye-lion at dynamic room temperatures.

In vitro antimicrobial activity of ginseng extract against Staphylococcus aureus, Salmonella Typhimurium and Listeria monocytogenes and its inhibitory effects on these pathogens in cooked ground beef

Present study is focused on exploring in vitro antimicrobial activity of ginseng extract (GE) against Staphylococcus aureus, Salmonella Typhimurium and Listeria monocytogenes and their biofilm forming ability, then determining its antimicrobial efficiency during the storage (4 and 10 °C) of cooked ground beef contaminated with these pathogens. Results revealed that the minimum inhibitory concentration (MIC) for S. aureus, S. typhimurium and L. monocytogenes were 90, 70 and 40 mg/mL, respectively. GE was also able to inhibit biofilm production by S. aureus and L. monocytogenes, whereas S. typhimurium did not produce biofilm with or without GE application. On the other hand, the results of GE aplication in ground beef indicated that GE incorporation at 0.5% or more reduced S. aureus and S. Typhmurium counts in cooked ground beef at the end of 30 d storage at 4 °C (P < 0.05). Using 1% or more GE totally inhibited S. Typhmurium after 15 d storage at 4 °C (P < 0.05). However, GE application did not affect S. aureus or S. Typhmurium counts in cooked ground beef stored at 10 °C. Furthermore, incorporation of 0.5% or more GE generally inhibited L. monocytogenes growth in cooked ground beef at the end of storage at both 4 and 10 °C (P < 0.05). In general, pH was lower in samples with GE than those without GE regardless of differences in the type of tested pathogen, storage time and temperatures (P < 0.05). Although similar aw was generally obtained on processing day, lower aw was observed in GE containing groups at the end of storage for both storage temperatures (P < 0.05). Oxidation reduction potential (ORP) in all groups generally increased during storage at both storage temperatures (P < 0.05). In conclusion, our results demonstrated that GE has an important role in controlling growth of tested pathogens and may be used as a natural agent by the meat industry to inhibit the growth of food-borne pathogens in cooked processed meat products during storage.

In Vitro Probiotic Characterization of Lactiplantibacillus plantarum Strains Isolated from Traditional Fermented Dockounou Paste

This study aimed to evaluate the probiotic properties of 10 lactic acid bacteria (LAB) isolated from artisanal fermented plantain dockounou paste. A preliminary characterization of the LAB isolates was performed based on phenotypic and several biochemical properties, which was subsequently confirmed through 16S rRNA gene sequencing analysis, indicating that these isolates belonged to the species Lactiplantibacillus plantarum. With regard to safety criteria, the strains exhibited no alpha or beta hemolysis activity. Nevertheless, the majority of LAB strains demonstrated high sensitivity to the antibiotics tested. The results demonstrated that the majority of the strains exhibited remarkably high survival rates under simulated gastrointestinal conditions, such as pH = 1.5 (81.18–98.15%), 0.3% bile salts (68.62–100.89%), 0.4% phenol (40.59–128.24%), as well as 0.1% pepsin and pH = 2.5 (88.54–99.78%). The LAB strains demonstrated elevated levels of cell surface properties, indicative of the presence of a considerable defensive mechanism against pathogens. Intact LAB cells exhibited significant antioxidant abilities (48.18–83.58%). They also demonstrated a pronounced inhibitory effect on the growth of foodborne pathogens. Enzyme pattern analysis revealed that the LAB isolates produced both proteases and cellulases, as well as pectinase and/or amylase activity. The potential of the L. plantarum strains FS43, FS44, and FS48, as indicated by the results obtained from the standard in vitro assays, makes them suitable for further study as potential probiotics.

Polysaccharide-Based Edible Biopolymer-Based Coatings for Fruit Preservation: A Review

Over the last decades, a significant rise in fruit consumption has been noticed as they contain numerous nutritional components, which has led to the rise in fruit production globally. However, fruits are highly liable to spoilage in nature and remain vulnerable to losses during the storage and preservation stages. Therefore, it is crucial to enhance the storage life and safeness of fruits for the consumers. To keep up the grade and prolong storage duration, various techniques are employed in the food sector. Among these, biopolymer coatings have gained widespread acceptance due to their improved characteristics and ideal substitution for synthetic polymer coatings. As there is concern regarding the safety of the consumers and sustainability, edible coatings have become a selective substitution for nurturing fruit quality and preventing decay. The application of polysaccharide-based edible coatings offers a versatile solution to prevent the passage of moisture, gases, and pathogens, which are considered major threats to fruit deterioration. Different polysaccharide substances such as chitin, pectin, carrageenan, cellulose, starch, etc., are extensively used for preparing edible coatings for a wide array of fruits. The implementation of coatings provides better preservation of the fruits such as mango, strawberry, pineapple, apple, etc. Furthermore, the inclusion of functional ingredients, including polyphenols, natural antioxidants, antimicrobials, and bio-nanomaterials, into the edible coating solution matrix adds to the nutritional, functional, and sensory attributes of the fruits. The blending of essential oil and active agents in polysaccharide-based coatings prevents the growth of food-borne pathogens and enhances the storage life of the pineapple, also improving the preservation of strawberries and mangoes. This paper aims to provide collective data regarding the utilization of polysaccharide-based edible coatings concerning their characteristics and advancements for fruit preservation.

Natural approach of using nisin and its nanoform as food bio-preservatives against methicillin resistant Staphylococcus aureus and E.coli O157:H7 in yoghurt

BackgroundNatural antimicrobial agents such as nisin were used to control the growth of foodborne pathogens in dairy products. The current study aimed to examine the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against methicillin resistant Staphylococcus aureus (MRSA) and E.coli O157:H7 during the manufacturing and storage of yoghurt. Nisin NPs were prepared using new, natural, and safe nano-precipitation method by acetic acid. The prepared NPs were characterized using zeta-sizer and transmission electron microscopy (TEM). In addition, the cytotoxicity of nisin NPs on vero cells was assessed using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined using agar well-diffusion method. Further, fresh buffalo’s milk was inoculated with MRSA or E.coli O157:H7 (1 × 106 CFU/ml) with the addition of either nisin or nisin NPs, and then the inoculated milk was used for yoghurt making. The organoleptic properties, pH and bacterial load of the obtained yoghurt were evaluated during storage in comparison to control group.ResultsThe obtained results showed a strong antibacterial activity of nisin NPs (0.125 mg/mL) against MRSA and E.coli O157:H7 in comparison with control and pure nisin groups. Notably, complete eradication of MRSA and E.coli O157:H7 was observed in yoghurt formulated with nisin NPs after 24 h and 5th day of storage, respectively. The shelf life of yoghurt inoculated with nisin nanoparticles was extended than those manufactured without addition of such nanoparticles.ConclusionsOverall, the present study indicated that the addition of nisin NPs during processing of yoghurt could be a useful tool for food preservation against MRSA and E.coli O157:H7 in dairy industry.

Functionalization of Polyhydroxyalkanoates (PHA)-Based Bioplastic with Phloretin for Active Food Packaging: Characterization of Its Mechanical, Antioxidant, and Antimicrobial Activities.

The formulation of eco-friendly biodegradable packaging has received great attention during the last decades as an alternative to traditional widespread petroleum-based food packaging. With this aim, we designed and tested the properties of polyhydroxyalkanoates (PHA)-based bioplastics functionalized with phloretin as far as antioxidant, antimicrobial, and morpho-mechanic features are concerned. Mechanical and hydrophilicity features investigations revealed a mild influence of phloretin on the novel materials as a function of the concentration utilized (5, 7.5, 10, and 20 mg) with variation in FTIR e RAMAN spectra as well as in mechanical properties. Functionalization of PHA-based polymers resulted in the acquisition of the antioxidant activity (in a dose-dependent manner) tested by DPPH, TEAC, FRAR, and chelating assays, and in a decrease in the growth of food-borne pathogens (Listeria monocytogenes ATCC 13932). Finally, apple samples were packed in the functionalized PHA films for 24, 48, and 72 h, observing remarkable effects on the stabilization of apple samples. The results open the possibility to utilize phloretin as a functionalizing agent for bioplastic formulation, especially in relation to food packaging.

Effect of Adding Lactoferrin on Some Foodborne Pathogens in Yogurt

Background: Lactoferrin is a natural biological active cationic protein that can be used as a yogurt additive to inhibit the growth of foodborne pathogens. Objectives: The present study evaluated the antimicrobial effects of lactoferrin against Bacillus cereus, Enterococcus faecalis, and Candida albicans inoculated in laboratory prepared yogurt at refrigerator temperature. Methods: The pre-warmed skimmed milk was inoculated by commercial starter and then divided into 3 parts, each inoculated by different inoculum and a certain concentration of lactoferrin (0.5% and 1.5%) and incubated at 42oC for 4 h till curd formation. Tenfold serial dilutions were performed for each group and refrigerated at4±1oC for up to 14 days to be examined every day. Results: The obtained results showed that the treated yogurt samples with lactoferrin had significant reductions in B. cereus, Ent. faecalis, and C. albicans counts than untreated samples (control positive). Generally, yogurt samples treated with 1.5% lactoferrin showed the highest reduction percentages on B. cereus and C. albicans than 0.5% lactoferrin. In addition, B. cereus showed more susceptibility to lactoferrin than Ent. faecalis; the maximum reduction of the inoculated B. cereus was observed on the sixth day of the incubation to be 99.99%. Maximum reduction of the tested C. albicans was observed after the seventh day. Conclusion: The application of lactoferrin showed a potentially significant antimicrobial effect against B. cereus, Ent. faecalis, and C. albicans in refrigerating conditions, so lactoferrin is recommended to be used in yogurt production for safe product manufacturing.

Insight into the antibacterial activity and membrane-damage mechanism of pyrrole-2-carboxylic acid against Listeria monocytogenes

Natural antimicrobials have potential to suppress the growth of foodborne pathogens. In this work, the antibacterial property and membrane-disruptive mechanism of pyrrole-2-carboxylic acid (PCA), against Listeria monocytogenes were elucidated. Leakage of cell constituents (K+ and nucleotide) and flow cytometric analysis indicated that PCA caused a significant change in the permeability and integrity of cell membrane of L. monocytogenes. Meanwhile, remarkable morphological alterations and membrane hyperpolarization of L. monocytogenes validated the disruptive ability of PCA on cell membrane. Additionally, PCA could interact with membrane protein, and cause changes in the conformation of protein. Untargeted lipidomics revealed that PCA triggered alternations in the composition and architecture of the membrane lipids mainly involved in glycerophospholipid and glycerolipid metabolism, thus leading to cell membrane dysfunction. Furthermore, PCA at concentration of 0.75 mg/mL could inhibit the contamination of L. monocytogenes in lettuce stem and beef, with a decrease of 2.4 log CFU/cm2 (P ＜ 0.05) for lettuce stem and 1.8 log CFU/cm2 (P ＜ 0.05) for beef after 10 days of storage. This work illuminates the key targets of PCA against the cell membrane of L. monocytogenes, facilitating the application of natural organic acids as candidate food preservatives in the food industry.

In silico evaluation of phytochemicals present in Bambusa polymorpha and Citrus limon extracts against Salmonella enteric Typhimurium combined with in vitro antimicrobial and acidic stress responsive studies

AbstractSalmonella enteric serovar Typhimurium is one of the causative agents for non‐typhoidal salmonellosis which is highly associated with the consumption animal products such as eggs, pork, and poultry. Phytochemicals present in plant extracts were reported to improve food safety by inhibiting the growth of foodborne pathogens. Herein, the antimicrobial activities of Citrus limon and Bambusa polymorpha extracts were evaluated for their effectiveness in reducing the log counts of strains of S. Typhimurium inoculated in ground pork. The incorporation of undiluted extracts has resulted in 3.95 and 1.88 log reduction of S. Typhimurium, respectively with 2 h of exposure. Phytochemicals in the extracts that interfere with the activity of outer membrane (OmpA) and efflux pump regulatory proteins (MdfA, RamA) were also identified and interactions were anticipated using molecular docking and molecular dynamics simulation (MDS) studies. This study has revealed that the major phytochemicals present in the extracts were viz. phenol‐2‐ethyl, paracresol, 2, 3‐dimethoxybenzoic acid, cyclobarbital, 3‐methylsalicylhydrazide, and 3‐methoxy‐5‐methylphenol. In order to evaluate the drug likeness and toxicity, phytochemicals were screened for their physiochemical and absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. ADMET studies has revealed that the screened phytochemicals with high docking scores had potent anti‐bacterial abilities and could be used in drug design studies to develop natural plant products to preferentially target the outer membrane and efflux pump regulatory proteins of S. Typhimurium, which are critically important for the survival of S. Typhimurium under stress condition.

Utilizing Imine Bonds to Create a Self-Gated Mesoporous Silica Material with Controlled Release and Antimicrobial Properties.

In recent years, silica nanomaterials have been widely studied as carriers in the field of antibacterial activity in food. Therefore, it is a promising but challenging proposition to construct responsive antibacterial materials with food safety and controllable release capabilities using silica nanomaterials. In this paper, a pH-responsive self-gated antibacterial material is reported, which uses mesoporous silica nanomaterials as a carrier and achieves self-gating of the antibacterial agent through pH-sensitive imine bonds. This is the first study in the field of food antibacterial materials to achieve self-gating through the chemical bond of the antibacterial material itself. The prepared antibacterial material can effectively sense changes in pH values caused by the growth of foodborne pathogens and choose whether to release antibacterial substances and at what rate. The development of this antibacterial material does not introduce other components, ensuring food safety. In addition, carrying mesoporous silica nanomaterials can also effectively enhance the inhibitory ability of the active substance.

Promising Probiotic Properties of the Yeasts Isolated from Rabilé, a Traditionally Fermented Beer Produced in Burkina Faso.

In recent years, research on yeasts as probiotics has gained more and more interest, which will allow the development of "new" products in the probiotics market. In this context, seventeen yeast strains isolated from Rabilé, a traditional beer produced in Burkina Faso, were assessed for their probiotic attributes. The yeast identification was performed by molecular methods, including PCR-RFLP and 5.8S-ITS region sequencing. Saccharomyces cerevisiae (14 strains) was the predominantly identified species, followed by Pichia kudriavzevii (2 strains) and Rhodotorula mucilaginosa (1 strain). Except for R. mucilaginosa, all yeast strains grew well at human temperature. The yeast strains showed high resistance when they were exposed to simulated gastrointestinal conditions. Auto-aggregation ability was between 70.20 ± 10.53% and 91.82 ± 1.96%, while co-aggregation with E. coli ranged from 24.92 ± 3.96% to 80.68 ± 9.53% and with S. enterica serovar Typhimurium from 40.89 ± 8.18% to 74.06 ± 7.94%. Furthermore, the hydrophobicity of isolated strains toward n-hexane was in the range from 43.17 ± 5.07% to 70.73 ± 2.42%. All yeast strains displayed high antioxidant capabilities, and the strains did not show hemolysis halos, such that they can be considered safe. Additionally, S. cerevisiae strains strongly inhibited the growth of foodborne pathogens. This is the first preliminary study to identify and characterize the yeast strains isolated from Rabilé with interesting probiotic properties.

Carvacrol and Cinnamaldehyde as Next Generation Antimicrobial Agents against Foodborne Pathogens: Antibacterial Efficacy and Synergistic Interaction with Nisin

Foodborne infections cause substantial issues all around the world, hence food safety is a major public health concern. The goal of this research is to provide information to the scientific community on the possible application of two plant essential oil molecules, Carvacrol (CAR) and Cinnamaldehyde (CN), as next-generation antimicrobials in the fight against foodborne pathogens. CAR and CN demonstrated outstanding dose-dependent antibacterial efficacy against 10 foodborne pathogens. Both Gram-positive and Gram-negative bacteria were suitably inhibited by the drugs. Antimicrobial activity of 10% v/v CAR and CN was much higher than that of the conventional antibiotic azithromycin (15g/disc). The study discovered that CAR and CN have very low MIC values (0.08% to 0.31% v/v), indicating that the compounds are efficacious even at very low concentrations. Even at 0.16% concentration, combining CAR and CN with Nisin (a widely available natural preservative) exhibited substantial synergism, with inhibition zones ranging from 8.5- 12.38 mm, decreasing the dose required to produce sufficient antimicrobial action. The findings imply that CAR and CN combined with nisin can be used as a natural antibacterial agent to limit the growth of foodborne pathogens and as a natural food preservative.&#x0D; Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 7-14

Development and characterization of active packaging nanofiber mats based on gelatin‑sodium alginate containing probiotic microorganisms to improve the shelf-life and safety quality of silver carp fillets

The current study aimed to incorporate Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus casei, and Lacticaseibacillus rhamnosus (~10 log CFU/ml) into gelatin‑sodium alginate nanofibers via electrospinning process in order to investigate the influence of fabricated mats on the growth of food-related pathogenic bacteria and shelf-life extension of refrigerated silver carp fillets in a two-week period. The strain-loaded nanofibers exhibited lower water vapor permeability, swelling index, moisture content, and tensile strength than the straight nanofibers (P < 0.05). The survival order of probiotics in nanofibers stored at 4, 25, and 37 °C for 14 days are as follows: L. acidophilus (8.15–9.35 log CFU/g) > L. reuteri (7.42–9.24 log CFU/g) > L. casei (7.41–9.13 log CFU/g) > L. rhamnosus (7.37–8.92 log CFU/g). The probiotic mats significantly delayed the growth of Vibrio parahaemolyticus, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in silver carp fillets in comparison with the unpackaged sample (P < 0.05). Moreover, the designated nanofibers improved the bacterial, chemical, and sensory properties of treated samples in comparison with the unpackaged samples throughout the study period. Our findings indicate that gelatin‑sodium alginate nanofibers are a suitable platform for the protection of living probiotics and present an alternative procedure for retarding the growth of food-borne pathogens and extending the shelf-life of fresh carp fillets under refrigerated storage conditions.

Sporulation and Biofilms as Survival Mechanisms of Bacillus Species in Low-Moisture Food Production Environments.

Low-moisture foods (LMF) have clear advantages with respect to limiting the growth of foodborne pathogens. However, the incidences of Bacillus species in LMF reported in recent years raise concerns about food quality and safety, particularly when these foods are used as ingredients in more complex higher moisture products. This literature review describes the interlinked pathways of sporulation and biofilm formation by Bacillus species and their underlying molecular mechanisms that contribute to the bacteriums' persistence in LMF production environments. The long-standing challenges of food safety and quality in the LMF industry are also discussed with a focus on the bakery industry.

Carboxymethyl cellulose and cardamom oil in a nanoemulsion edible coating inhibit the growth of foodborne pathogens and extend the shelf life of tomatoes

A nanoemulsion edible coating solution was prepared using carboxymethyl cellulose (CMC) and cardamom essential oil (CEO) with satisfactory physical properties like size (87 ± 2.3 nm), polydispersity index (0.154 ± 0.07), ζ-potential (−27.30 ± 3.2 mV), whiteness index (86.32 ± 0.34) and pH (7.3 ± 0.48). The minimum inhibitory concentrations (MICs) of Carboxymethyl cellulose-based cardamom essential oil nanoemulsion against Escherichia coli, and Listeria monocytogenes were found to be nearly 10%. It reduced the biofilm formation by inhibiting the EPS production of both of these bacteria under both single and mixed-species culture conditions. The nanoemulsion edible coating significantly reduced the loss of fruit weight (7.32 ± 2.4%), firmness (1.3 times), total soluble solids, and titratable acidity of tomatoes by reducing oxidative stress and increasing antioxidant enzymes during 15 days of storage. By maintaining the levels of antioxidant enzymes, the nanoemulsion edible coating prevented oxidative damage-induced senescence of tomatoes. The microbial load was found to be lower in coated tomatoes, indicating that microbial spoilage was prevented. Hence, the nanoemulsion (CMC-CEONE) edible coating appears to have a high potential to extend the shelf life of fresh tomatoes during storage at 25 ± 2 °C temperature.

Recent developments of lactic acid bacteria and their metabolites on foodborne pathogens and spoilage bacteria: Facts and gaps

Lactic acid bacteria (LAB) are common microorganisms found in various ecosystems including in plants, fermented foods, and the human body. Exploring the biodiversity of lactic acid microflora and characterization of LAB is a new approach to form a variety of starter communities to create innovative nutritional food matrices. There has been growing interest in LAB isolated from non-dairy environments as these bacteria exhibit significant metabolic diversity and have unique taste-forming activities. Disease may be prevented, or treated by LAB but the treatment of disease conditions with LAB is highly dependent on the host's microbiome and diet and varies in both effectiveness and side effects from individual to individual. Future perspectives on the study of LAB may be related to the expansion of our knowledge in the fields of genetics and genetic engineering. The application of genetic science may help to improve existing strains and develop new strains with characteristics designed for specific purposes. Therefore, the preservative effects of LAB and their metabolites, as well as their interaction on the growth of food borne pathogens and food spoilage microorganisms were elucidated. In addition, the competitive models for microbial growth between LAB and other microorganisms as well as the role of LAB in the elimination of toxic compounds in food products were discussed. Moreover, the review provided an overview of the risks and benefits of using LAB in the food industry.

Growth evaluation of Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes in fresh fruit and vegetable juices via predictive modeling

Fresh juices are often exposed to microbial contamination due to their minimal processing, which can lead to foodborne disease. Therefore, in this study, in order to understand the behavior of foodborne pathogens (Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes) contained in fresh juice, the growth of the foodborne pathogens was predicted using the modified Gompertz model in six vegetable juices (beet, carrot, kale, celery, cabbage, and red cabbage) and two fruit juices (lemon and grapefruit) stored at 10 °C. Except for those of S. typhimurium in kale juice (maximum growth rate [GR], 0.05; lag time [LT], 118.30), the GR and LT of the foodborne pathogens were predicted to range from 0.04 to 0.08 and 6.37 to 35.48, respectively, in the vegetable juices. The performance of modified Gompertz modeling was confirmed to be in the range of 0.91–1.14 in terms of the bias factor (Bf) and 1.05 to 1.62 in terms of the accuracy factor (Af). The predictive modeling results from this study showed that vegetable juice supported the growth of foodborne pathogens.

Development of Desiccation-Tolerant Probiotic Biofilms Inhibitory for Growth of Foodborne Pathogens on Stainless Steel Surfaces.

Lactic acid bacteria biofilms can be used to reduce foodborne pathogen contamination in the food industry. However, studies on growth inhibition of foodborne pathogens by inducing biofilm formation of antagonistic microorganisms on abiotic surfaces are rare. We developed a desiccation-tolerant antimicrobial probiotic biofilm. Lactobacillus sakei M129-1 and Pediococcus pentosaceus M132-2 isolated from fermented Korean foods were found to exhibit broad-spectrum antibacterial activity against Bacillus cereus, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica. Their biofilm levels were significantly (p < 0.05) higher on stainless steel than on polyethylene or ceramic. Biofilms of both isolates showed significantly (p < 0.05) enhanced resistance against desiccation (exposure to 43% atmospheric relative humidity) as compared with the isolates not in the biofilm form. The antimicrobial activity of the isolates was sustained in dried biofilms on stainless steel surface; the initial number of foodborne pathogens (average 7.0 log CFU/mL), inoculated on stainless steel chips containing L. sakei M129-1 or P. pentosaceus M132-2 biofilm decreased to less than 1.0 log CFU within 48 h. The lactic acid bacteria antibacterial biofilms developed in this study may be applied to desiccated environmental surfaces in food-related environments to improve microbiological food safety.