scholarly journals Biocontrol of Escherichia coli O157:H7 in ready-to-eat salad using a lytic bacteriophage

2017 ◽  
Vol 73 (7) ◽  
pp. 422-424
Author(s):  
Gizem Cufaoglu ◽  
Bahar Onaran Naim Deniz Ayaz ◽  
Muammer Goncuoglu ◽  
Fatma Seda Ormancı
Keyword(s):  
Biocontrol Agent ◽  
Foodborne Pathogen ◽  
Storage Period ◽  
Storage Conditions ◽  
Heating Process ◽  
Lytic Bacteriophage ◽  
E Coli ◽  
C Storage ◽  
Life Threatening ◽  
In The Beginning

E. coli O157:H7 is a life threatening foodborne pathogen associated with thousands of infections. Controlling such bacterial pathogens in raw and ready-to-eat foods has gained urgency with each passing day. The use of specific virulent bacteriophages as a biocontrol agent on minimally processed foods is an effective, natural and non-destructive treatment. This study was aimed at determining the efficiency of a lytic bacteriophage against E. coli O157:H7 in ready-to-eat salads. For this purpose, E. coli O157:H7 NCTC 12900 (EC00) and nalidixic acid resistant E. coli O157:H7 ATCC 43895 (NA-EC95) were used as the model bacterium in decontamination trials of mayonnaise based ready-to-eat salads which are consumed without any heating process and include beans, carrots, potatoes, pickled cucumbers and salami. A previously described phage M8AEC16 which was classified in Myoviridae family was used as the biocontrol agent. The highest reductions were observed at 22°C storage conditions. Reductions reaching up to 2.7 log cfu/g of viable E. coli O157:H7 counts were observed in the beginning of the storage period. The findings of the study showed that phage M8AEC16 can be used as a biocontrol agent in the decontamination of E. coli O157:H7 in such mayonnaise based ready-to-eat salads.

Real-Time Bioluminescence Analysis of Escherichia coli O157:H7 Survival on Livestock Meats Stored Fresh, Cold, or Frozen

2018 ◽  
Vol 81 (11) ◽  
pp. 1906-1912 ◽  
Author(s):  
SEONG B. PARK ◽  
SHECOYA B. WHITE ◽  
CHRISTY S. STEADMAN ◽  
CLAY A. CAVINDER ◽  
SCOTT T. WILLARD ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Bacterial Growth ◽  
Room Temperature ◽  
Storage Conditions ◽  
Escherichia Coli O157 ◽  
Production Environment ◽  
Real Time Monitoring ◽  
E Coli ◽  
C Storage

ABSTRACT Foodborne bacteria such as Escherichia coli O157:H7 can cause severe hemorrhagic colitis in humans following consumption of contaminated meat products. Contamination with pathogenic bacteria is frequently found in the food production environment, and adequate household storage conditions of purchased foods are vital for illness avoidance. Real-time monitoring was used to evaluate bacterial growth in ground horse, beef, and pork meats maintained under various storage conditions. Various levels of E. coli O157:H7 carrying the luxCDABE operon, which allows the cells to emit bioluminescence, were used to inoculate meat samples that were then stored at room temperature for 0.5 day, at 4°C (cold) for 7 or 9 days, or −20°C (frozen) for 9 days. Real-time bioluminescence imaging (BLI) of bacterial growth was used to assess bacterial survival or load. Ground horse meat BLI signals and E. coli levels were dose and time dependent, increasing during room temperature and −20°C storage, but stayed at low levels during 4°C storage. No bacteria survived in the lower level inoculum groups (101 and 103 CFU/g). With an inoculum of 107 CFU/g, pork meats had higher BLI signals than did their beef counterparts, displaying decreased BLI signals during 7 days storage at 4°C. Both meat types had higher BLI signals in the fat area, which was confirmed with isolated fat tissues in the beef meat. Beef lean and fat tissues contrasted with both pork fat and lean tissues, which had significantly higher BLI signals and bacterial levels. BLI appears to be a useful research tool for real-time monitoring of bacterial growth and survival in various stored livestock meats. The dependence of E. coli O157:H7 growth on meat substrate (fat or lean) and storage conditions may be used as part of an effective antibacterial approach for the production of safe ground horse, beef, and pork meats.

scholarly journals Efficacy of Bacteriophage Cocktail to Control E. coli O157:H7 Contamination on Baby Spinach Leaves in the Presence or Absence of Organic Load

2021 ◽  
Vol 9 (3) ◽  
pp. 544
Author(s):  
Badrinath Vengarai Jagannathan ◽  
Steven Kitchens ◽  
Paul Priyesh Vijayakumar ◽  
Stuart Price ◽  
Melissa Morgan
Keyword(s):  
Foodborne Pathogens ◽  
Fruits And Vegetables ◽  
Healthy Lifestyle ◽  
Foodborne Pathogen ◽  
Organic Load ◽  
Lytic Bacteriophage ◽  
Foodborne Illnesses ◽  
E Coli ◽  
Pathogen Reduction ◽  
Spinach Leaves

Fruits and vegetables are high in nutrients that are essential for a healthy lifestyle. However, they also harbor an extensive array of microorganisms such as bacteria, which can be beneficial, neutral, or pathogenic. Foodborne pathogens can contaminate produce at any stage from the farm to the consumer’s table. Appropriate washing techniques using sanitizers can reduce the risk of pathogen contamination. Issues related to maintaining concentration, efficacy, and other problems have been a challenge for the food industry and, when left unresolved, have led to different outbreaks of foodborne illnesses. In this study, the efficacy of a lytic bacteriophage cocktail was examined for its ability to infect and reduce the contamination of Escherichia coli O157:H7 (E. coli O157:H7), in media with a high organic load, using a microplate technique. The study was conducted for 3 h to determine if the bacteriophage cocktail could reduce the pathogen in the presence of a high organic load. A significant (p < 0.05) reduction in the population of E. coli O157:H7 was observed, representing a 99.99% pathogen reduction at the end of 3 h. Fresh spinach leaves were washed in sterile potable or organic water (~9000 ppm organic load) containing E. coli O157:H7 and a bacteriophage cocktail to study the effectiveness of bacteriophages against the foodborne pathogen. Results indicated that the bacteriophage significantly (p < 0.05) reduced the contamination of E. coli O157:H7 in both situations. The study also demonstrated the bacteriophages’ ability to infect and reduce the pathogen in an organic-rich environment. This characteristic differs from commercially available sanitizers that have demonstrated a tendency to bind with the available organic load. Thus, these studies highlight the advantage of employing bacteriophages during produce wash to eliminate foodborne pathogen contamination on fruits and vegetables.

Effect of Packaging and Storage Temperature on the Survival of Listeria monocytogenes Inoculated Postprocessing on Sliced Salami

2007 ◽  
Vol 70 (10) ◽  
pp. 2313-2320 ◽  
Author(s):  
ANTONIA S. GOUNADAKI ◽  
PANAGIOTIS N. SKANDAMIS ◽  
ELEFTHERIOS H. DROSINOS ◽  
GEORGE-JOHN E. NYCHAS
Keyword(s):  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Storage Period ◽  
Storage Conditions ◽  
Quantitative Microbial Risk Assessment ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
C Storage ◽  
High Storage Temperature ◽  
High Concentrations

The survival of postprocess Listeria monocytogenes contamination on sliced salami, stored under the temperatures associated with retail and domestic storage, was investigated. Sliced salami was inoculated with low and high concentrations of L. monocytogenes before being packaged under vacuum or air. Survival of L. monocytogenes was determined after storage of sausages for 45 or 90 days for low or high sample inocula, respectively, at 5, 15, and 25°C. All survival curves of L. monocytogenes were characterized by an initial rapid inactivation within the first days of storage, followed by a second, slower inactivation phase or “tailing.” Greater reduction of L. monocytogenes was observed at the high storage temperature (25°C), followed by ambient (15°C) and chill (5°C) storage conditions. Moreover, vacuum packaging resulted in a slower destruction of L. monocytogenes than air packaging, and this effect increased as storage temperature decreased. Although L. monocytogenes numbers decreased to undetectable levels by the end of the storage period, the time (in days) needed for this reduction and for the total elimination of the pathogen decreased with high temperature, aerobic storage, and high inoculum. Results of this study clearly indicated that the kinetics of L. monocytogenes were highly dependent on the interaction of factors such as storage temperature, packaging conditions, and initial level of contamination (inoculum). These results may contribute to the exposure assessment of quantitative microbial risk assessment and to the establishment of storage-packaging recommendations of fermented sausages.

Inhibitory effect of bacteriocins againstEscherichia coliO157:H7

2019 ◽  
Vol 25 (6) ◽  
pp. 504-514 ◽  
Author(s):  
Nilgün Öncül ◽  
Zeliha Yıldırım
Keyword(s):  
Foodborne Pathogen ◽  
Storage Period ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Pathogenic Microorganisms ◽  
E Coli ◽  
Uht Milk ◽  
Milk Samples ◽  
White Cheese ◽  
Storage Temperatures

The purpose of this study was to explore the activity of bacteriocin enterocin KP and lactococcin BZ against Escherichia coli O157:H7, a Gram-negative foodborne pathogen, in ultra-high temperature (UHT) milks with different fat ratios. Enterocin KP and lactococcin BZ were produced from two bacteriocinogenic strains, isolated in previous studies from White cheese and Boza. Full fat (3.0%), half fat (1.5%), and low fat (<0.1% fat) UHT milks inoculated with 102, 104, and 106CFU/ml of E. coli O157:H7 were treated with different concentrations (400, 800, 1600, and 2500 AU/ml) of lactococcin BZ, enterocin KP, or a combination of both and stored at 4 or 20 ℃ for 20 days. The survival of E. coli O157:H7 was determined at both storage temperatures during the storage period of 20 days. Lactococcin BZ and enterocin KP had a bactericidal impact on E. coli O157:H7 in all UHT milk samples either separately or in combination. However, antibacterial activity of the bacteriocins decreased with increasing fat content of milk and inoculum levels of bacterium. The results of this study indicate that lactococcin BZ and enterocin KP may be useful candidates either separately or in combination as biopreservatives for use in the dairy industry to control the growth of pathogenic microorganisms.

scholarly journals Investigation of the Physical, Chemical and Microbiological Stability of Losartan Potassium 5 mg/mL Extemporaneous Oral Liquid Suspension

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 301
Author(s):  
Lisa Foley ◽  
Jennifer Toney ◽  
James W. Barlow ◽  
Maura O’Connor ◽  
Deirdre Fitzgerald-Hughes ◽  
...  
Keyword(s):  
Shelf Life ◽  
Storage Conditions ◽  
Losartan Potassium ◽  
Microbial Count ◽  
E Coli ◽  
Physical Chemical ◽  
Liquid Suspension ◽  
Oral Liquid ◽  
Microbiological Stability ◽  
Stability Data

Extemporaneous oral liquid preparations are commonly used when there is no commercially available dosage form for adjustable dosing. In most cases, there is a lack of stability data to allow for an accurately assigned shelf life and storage conditions to give greater confidence of product safety and efficacy over its shelf life. The aim of this study was to evaluate the physical, chemical and microbiological stability of an extemporaneous oral liquid suspension of losartan potassium, 5 mg/mL, used to treat paediatric hypertension in Our Lady’s Children’s Hospital Crumlin, Ireland. The losartan content of extemporaneous oral suspensions, prepared with and without addition of water, was measured by UV and confirmed by HPLC analysis. Suspensions were stored at 4 °C and room temperature (RT) and were monitored for changes in; pH, colour, odour, re-dispersibility, Total Aerobic Microbial Count, Total Yeast and Mould Count and absence of E. coli. Results showed that suspensions prepared by both methods, stored at 4 °C and RT, were physically and microbiologically stable over 28 days. Initial losartan content of all suspensions was lower than expected at 80–81% and did not change significantly over the 28 days. HPLC and NMR did not detect degradation of losartan in the samples. Suspensions prepared in water showed 100% losartan content. The reduced initial losartan content was confirmed by HPLC and was related to the acidic pH of the suspension vehicle. Physiochemical properties of the drug are important factors for consideration in the selection of suspension vehicle for extemporaneous compounding of oral suspensions as they can influence the quality, homogeneity and efficacy of these preparations.

scholarly journals The Food Anti-Microbials β-Phenylethylamine (-HCl) and Ethyl Acetoacetate Do Not Change during the Heating Process

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 418
Author(s):  
Shelley M. Horne ◽  
Angel Ugrinov ◽  
Birgit M. Prüβ
Keyword(s):  
Microbial Activity ◽  
Food Processing ◽  
Ethyl Acetoacetate ◽  
Mass Spectra ◽  
Heating Process ◽  
Toxic Compounds ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Cooking Process ◽  
Early Retention

β-Phenylethylamine hydrochloride (PEA-HCl) and ethyl acetoacetate (EAA) are anti-microbials with applications in food processing. As food anti-microbials, the compounds will have to withstand the cooking process without changing to toxic compounds. With this Communication, we address the question of whether PEA and EAA are altered when heated to 73.9 °C or 93.3 °C. A combination of gas chromatography and mass spectrometry was used to analyze solutions of PEA(-HCl) or EAA in beef broth or water. In addition, the anti-microbial activity of PEA-HCl and EAA was compared between heated and unheated samples at a range of concentrations. The gas chromatograms of PEA(-HCl) and EAA showed one peak at early retention times that did not differ between the heated and unheated samples. The mass spectra for PEA and EAA were near identical to those from a spectral database and did not show any differences between the heated and unheated samples. We conclude that PEA(-HCl) and EAA formed pure solutions and were not altered during the heating process. In addition, the anti-microbial activity of PEA-HCl and EAA did not change after the heating of the compounds. Regardless of temperature, the minimal inhibitory concentrations (MICs) for PEA-HCl were 20.75 mmol mL−1 for Escherichia coli and Salmonella enterica serotype Typhimurium. For EAA, the MICs were 23.4 mmol mL−1 for E. coli and 15.6 mmol mL−1 for S. enterica.

An Aggregation-Induced Emission Material Labeling Antigen-Based Lateral Flow Immunoassay Strip for Rapid Detection of Escherichia coli O157:H7

2021 ◽  
pp. 247263032098193
Author(s):  
Cheng Liu ◽  
Shuiqin Fang ◽  
Yachen Tian ◽  
Youxue Wu ◽  
Meijiao Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Test Strip ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Lateral Flow Immunoassay ◽  
Escherichia Coli O157 ◽  
Aggregation Induced Emission ◽  
E Coli

Escherichia coli O157:H7 ( E. coli O157:H7) is a dangerous foodborne pathogen, mainly found in beef, milk, fruits, and their products, causing harm to human health or even death. Therefore, the detection of E. coli O157:H7 in food is particularly important. In this paper, we report a lateral flow immunoassay strip (LFIS) based on aggregation-induced emission (AIE) material labeling antigen as a fluorescent probe for the rapid detection of E. coli O157:H7. The detection sensitivity of the strip is 105 CFU/mL, which is 10 times higher than that of the colloidal gold test strip. This method has good specificity and stability and can be used to detect about 250 CFU of E. coli O157:H7 successfully in 25 g or 25 mL of beef, jelly, and milk. AIE-LFIS might be valuable in monitoring food pathogens for rapid detection.

scholarly journals Evolution of Food Safety Features and Volatile Profile in White Sturgeon Caviar Treated with Different Formulations of Salt and Preservatives during a Long-Term Storage Time

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 850
Author(s):  
Annalaura Lopez ◽  
Federica Bellagamba ◽  
Erica Tirloni ◽  
Mauro Vasconi ◽  
Simone Stella ◽  
...  
Keyword(s):  
Food Safety ◽  
Organic Acids ◽  
Solid Phase ◽  
Current Trend ◽  
Storage Period ◽  
Storage Conditions ◽  
Sensory Profile ◽  
Volatile Profile ◽  
Safety Parameters ◽  
Statistic Model

Caviar is a semi-preserved fish preparation in which cold storage (around 0 °C) and packaging under anaerobic conditions are fundamental to guarantee adequate safety parameters. Consumers seem to prefer caviar prepared with food salt only, but according to the needs of the different distribution channels, some preservatives are used in order to prolong its shelf life and to allow less restrictive storage conditions. Traditionally, the most common preservative was sodium tetraborate (borax), a salt that contributes to the sensory profile of caviar. However, due to its toxicity, borax has been banned in many countries, and the current trend is to reduce or eliminate its use. In this study, we evaluated the evolution of food safety parameters (pH, water activity, microbiological parameters) and the volatile profile during 14 months of storage in caviar samples treated with three different preservatives: I. exclusively NaCl, II. a mixture of borax and NaCl, and III. a mixture of organic acids and salts. Microbial presence was studied by means of plate counts; volatile organic compounds were identified on the sample headspace by means of solid phase microextraction with gas-chromatography and mass spectrometry. Results showed relevant differences among the three treatments investigated, with salt samples characterized by the highest viable counts and the greatest presence of volatile products driven by oxidative and spoilage processes, mainly occurring toward lipid and amino acids. On the contrary, the mixture of organic acids and salts showed the best response during the entire storage period. Finally, the employment of a multiparametric statistic model allowed the identification of different clusters based on the time of ripening and the preservative treatments used.

KINETIC MODEL FOR THERMAL DEHYDROCHLORINATION OF CHLORINATED NATURAL RUBBER WITH DIFFERENT CHLORINE CONTENT

2014 ◽  
Vol 87 (2) ◽  
pp. 370-382
Author(s):  
Jing Chen ◽  
Lanzhen He ◽  
Yasheng Chen ◽  
Jieping Zhong ◽  
Canzhong He ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Storage Conditions ◽  
Chlorine Content ◽  
Heating Process ◽  
Lower Temperature ◽  
Novel Model ◽  
Derivative Thermogravimetry ◽  
Selection Of ◽  
Thermo Oxidative Degradation

ABSTRACT A novel model for calculating dehydrochlorination kinetics at a lower temperature of chlorinated natural rubber (CNR) is presented. It has been observed that dehydrochlorination is complex and involves three different stages. A model that accounts for dehydrochlorination at lower temperature is proposed. The kinetic parameters are obtained from dehydrochlorination experiments at 60–90 °C. The results of the kinetic calculation show that the apparent activation energy decreases with an increment of chlorine content. Higher chlorine content CNR makes it easier to remove hydrochloric acid when heated, but its dehydrochlorination rate affected by temperature is significantly less than that of the sample with a lower chlorine content. The thermogravimetric/derivative thermogravimetry results show that the beginning temperature of thermo-oxidative degradation rises with the increment of chlorine content. During the heating process, the higher chlorine content CNR is more stable than the lower one. The results suggest the storage conditions and basis for selection of appropriate temperature for the preparation of CNR from latex.

Characteristics of Packaged Water under Different Storage Conditions Within Osogbo Metropolis

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
O.O Fadipe
Keyword(s):  
Room Temperature ◽  
Control Unit ◽  
Storage Conditions ◽  
Prolonged Storage ◽  
E Coli ◽  
Physico Chemical ◽  
Routine Basis ◽  
Regulatory Bodies ◽  
Microbiological Analyses ◽  
Sachet Water

The study investigated the characteristics of packaged water stored under ambient and sunlight conditions. This is with a view to testing the effect of prolonged storage under different storage conditions on its quality. In addition it analyzed the interactions between the parameters. Two packs each of bottled and sachet water was purchased from each factory at the point of production and ready for distribution to wholesalers. Twenty eight pieces of packaged water from each factory were kept at room temperature and the same quantity were kept under sunlight. Physico-chemical and microbiological analyses were carried out on the remaining packaged water within 24hrs. Half of the samples stored at the two storage conditions were removed for analysis at 3 weeks while the remaining half was analyzed after 6weeks. The physico-chemical characteristics were within the WHO recommended values except for the pH of some samples that have values in the acidic range of 6.2-6.48. All the physico-chemical values increased for samples kept under sunlight. All the water samples showed growth in faecal coliform (4-46 cfu/100 mL) and E. coli (0-13 cfu/100 mL) for samples kept under sunlight at three weeks and this growth increased to the sixth week. The presence of E. coli is an indication that the packaged water is not pure. Displaying packaged water under the sunlight and storing beyond 3 weeks by vendors have effect on the potability of the product. The regulatory bodies should raise awareness and ensure manufacturer have a quality control unit to test on a routine basis.

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