scholarly journals Use of bacteriophages as biological control agents in horticulture

2019 ◽  
Vol 40 (1) ◽  
pp. 47
Author(s):  
Rhianna O'Regan ◽  
Annaleise Wilson ◽  
İpek Kurtböke
Keyword(s):  
Ecosystem Health ◽  
Pathogenic Bacteria ◽  
Control Strategies ◽  
Fresh Produce ◽  
Bacterial Diseases ◽  
E Coli ◽  
Development Of Resistance ◽  
Preventative Measures ◽  
Laboratory Report ◽  
Colony Forming Units

Bacterial diseases in horticultural settings or infestation of fresh produce with human pathogenic bacteria can constitute a serious public health risk. To control horticultural bacterial diseases, chemical control strategies have traditionally been used, such as the application of bactericides and copper-based products, which resulted in development of resistance in bacteria against these agents. Moreover, the use of such chemical preventative measures on fresh produce can detrimentally affect human, animal and ecosystem health. Bacteriophages have been used to control pathogenic bacteria since the 1920s due to their specificity against host bacteria, as well as their ability to survive and infect their host without detrimental effects to the surrounding environments. As a result, their targeted host specific applications in horticultural settings can be of interest to growers as well as to the consumers. In this laboratory report, the efficacy of a bacteriophage cocktail when applied to fresh herbs inoculated with Escherichia coli was determined. Significant (P ≤ 0.001) reductions in E. coli colony forming units were observed in phage treated herb samples compared to counts in the control. These findings suggest that bacteriophage present as an alternative biocontrol for E. coli in horticulture.

scholarly journals Dietary Willow Bark Extract for Broilers Reared Under Heat Stress

2018 ◽  
Vol 75 (2) ◽  
pp. 92 ◽  
Author(s):  
Mihaela SARACILA ◽  
Tatiana Dumitra PANAITE ◽  
Petru Alexandru VLAICU ◽  
Cristina TABUC ◽  
Mihai Laurentiu PALADE ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bark Extract ◽  
Broiler Performance ◽  
E Coli ◽  
Light Regimen ◽  
Caecal Content ◽  
Colony Forming Units ◽  
Conventional Diet ◽  
White Willow ◽  
Willow Bark

A 28-day feeding trial was conducted on 60, Cobb 500 broilers (14 days), assigned to 2 groups (C, E) housed in an experimental hall (32° C, 23 h light regimen). Compared to the conventional diet C, the experimental diet (E) included 1% white willow bark extract (WBE). At 42 days of age, 6 blood samples /group were collected and 6 broilers/ group were slaughtered and caecal content was collected. The dietary WBE didn’t influence broiler performance. The serum concentrations of glycaemia, cholesterol and triglycerides were lower (P <0.05) in E group than in C group. E broilers had the lowest count (P<0.05) of Enterobacteriaceae, E. coli and staphylococci colony forming units in the caecal content. The inclusion of WBE (1%) in the diet of broilers reared at 32° C had an hypocholesterolemiant and hypoglycaemic effect and reduced the pathogenic bacteria in the caecum.

Larvicidal activity ofBacillus thuringiensisvar.israelensisCry11Aa toxin againstHaemonchus contortus

Parasitology ◽  
2016 ◽  
Vol 143 (12) ◽  
pp. 1665-1671 ◽  
Author(s):  
ANA PAULA DE SOUZA STORI DE LARA ◽  
LUCAS BIGOLIN LORENZON ◽  
ANA MUÑOZ VIANNA ◽  
FRANCISCO DENIS SOUZA SANTOS ◽  
LUCIANO SILVA PINTO ◽  
...  
Keyword(s):  
Control Strategies ◽  
Gastrointestinal Parasites ◽  
Effective Control ◽  
Bacterial Suspension ◽  
Control Group ◽  
E Coli ◽  
New Class ◽  
Colony Forming Units ◽  
Group A ◽  
Sheep Production

SUMMARYEffective control of gastrointestinal parasites is necessary in sheep production. The development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. Biological control strategies present an alternative to this problem. In the current study, we tested the larvicidal effects ofBacillus thuringiensisvar.israelensisCry11Aa toxin againstHaemonchus contortuslarvae. Bacterial suspensions [2 × 108colony-forming units (CFU) g−1of the feces] ofB. thuringiensisvar.israelensisand recombinantEscherichia coliexpressing Cry11Aa toxin were added to naturallyH. contortusegg-contaminated feces. The larvae were quantified, and significant reductions of 62 and 81% (P< 0·001) were, respectively observed, compared with the control group. A 30 mL bacterial suspension (1 × 108CFU mL−1) ofB. thuringiensisvar.israelensisand recombinantE. coliexpressing Cry11Aa toxin were then orally administered to lambs naturally infected withH. contortus. Twelve hours after administration, feces were collected and submitted to coprocultures. Significant larvae reductions (P< 0·001) of 79 and 90% were observed respectively compared with the control group. The results suggest that the Cry11Aa toxin ofB. thuringiensisvar.israelensisis a promising new class of biological anthelmintics for treating sheep againstH. contortus.

Antimicrobial activity of Commercial essential oils on human pathogens

2021 ◽  
pp. 4440-4444
Author(s):  
B. R. Malathy ◽  
Sweetlin Ajitha P ◽  
Sangeetha K. S ◽  
Swetha Thampy ◽  
Kamala G
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Steam Distillation ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Aromatic Plants ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Development Of Resistance

Essential oils (EOs) are natural extracts from the seeds, stems, roots, flowers, bark and other parts of the plant prepared by steam distillation. They are complex, volatile, natural compounds formed by aromatic plants as secondary metabolites. They are known for their bactericidal, virucidal, fungicidal, sedative, anti-inflammatory, analgesic, spasmolytic and locally anesthetic properties. They are generally composed of a combination of substances like terpenes, phenolics, aldehydes or alcohols. The complex composition and different mechanisms of action of EOs may be an advantage over other antimicrobials to prevent the development of resistance of pathogenic bacteria. With this background, the aim of this study was to evaluate the antimicrobial activity of five essential oils like basil, lime, rosemary, thyme and canada balsam against 14 microbes. The effects of essential oil on the selected microbes were determined by agar well diffusion method. The zone of inhibition was observed and measured in millimeter. Essential oils which showed inhibitory diameter >15 mm were further tested to determine the minimum inhibitory concentration (MIC). S. aureus, E. coli, S. mutans, S. sanguinis, C. albicans and M. furfur were inhibited by all essential oils. K. pneumoniae, P. aeruginosa and E .faecalis were inhibited only by thyme and not by other essential oils. The MIC values ranged from 50% to 0.10%. The least MIC value of 0.10% was shown by thyme and basil to S. aureus, thyme to E.coli and all essential oils against C. albicans except lime.

scholarly journals Analysis of Biofilm Formation on the Surface of Organic Mung Bean Seeds, Sprouts and in the Germination Environment

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 542
Author(s):  
Marcin Kruk ◽  
Monika Trząskowska
Keyword(s):  
Mung Bean ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Bacterial Biofilms ◽  
Limiting Factor ◽  
E Coli ◽  
Germination Process ◽  
Colony Forming Units ◽  
Seed Disinfection ◽  
The Impact

This study aimed to analyse the impact of sanitation methods on the formation of bacterial biofilms after disinfection and during the germination process of mung bean on seeds and in the germination environment. Moreover, the influence of Lactobacillus plantarum 299v on the growth of the tested pathogenic bacteria was evaluated. Three strains of Salmonella and E. coli were used for the study. The colony forming units (CFU), the crystal violet (CV), the LIVE/DEAD and the gram fluorescent staining, the light and the scanning electron microscopy (SEM) methods were used. The tested microorganisms survive in a small number. During germination after disinfection D2 (20 min H2O at 60 °C, then 15 min in a disinfecting mixture consisting of H2O, H2O2 and CH₃COOH), the biofilms grew most after day 2, but with the DP2 method (D2 + L. plantarum 299v during germination) after the fourth day. Depending on the method used, the second or fourth day could be a time for the introduction of an additional growth-limiting factor. Moreover, despite the use of seed disinfection, their germination environment could be favourable for the development of bacteria and, consequently, the formation of biofilms. The appropriate combination of seed disinfection methods and growth inhibition methods at the germination stage will lead to the complete elimination of the development of unwanted microflora and their biofilms.

scholarly journals The Antimicrobial Efficacy Of Plasma Activated Water Is Modulated By Reactor Design And Water Composition

2021 ◽  
Author(s):  
Joanna G Rothwell ◽  
David Alam ◽  
Dee A Carter ◽  
Behdad Soltani ◽  
Robyn McConchie ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Tap Water ◽  
Fresh Produce ◽  
Critical Role ◽  
Reactive Species ◽  
Antimicrobial Efficacy ◽  
Model Organisms ◽  
Atmospheric Conditions ◽  
E Coli ◽  
Plasma Activated Water

Plasma activated water (PAW) contains a cocktail of reactive oxidative species and free radicals and has demonstrated efficacy as a sanitizer for fresh produce, however there is a need for further optimization. The antimicrobial efficacy of PAW produced by a bubble spark discharge (BSD) reactor and a dielectric barrier discharge-diffuser (DBDD) reactor operating at atmospheric conditions with air, discharge frequencies of 500, 1000 and 1500 Hz, and MilliQ and tap water, was investigated with model organisms Listeria innocua and Escherichia coli.  Optimal conditions were subsequently employed for pathogenic bacteria Listeria monocytogenes, E. coli and Salmonella enterica. PAW generated with the DBDD reactor decontaminated more than 6-log CFU of bacteria within 1 minute of treatment. The BSD-PAW, while attaining high CFU reduction was less effective, particularly for L. innocua. Analysis of physicochemical properties revealed BSD-PAW had a greater variety of reactive species than DBDD-PAW. Scavenger assays were employed to specifically sequester reactive species, including the short-lived superoxide (?O2-) radical that could not be directly measured in the PAW. This demonstrated a critical role of superoxide for the inactivation of both E. coli and L. innocua by DBDD-PAW, while in BSD-PAW it had a role in L. innocua inactivation only. Overall, this study demonstrates the potential of DBDD-PAW in fresh produce, where there is a need for sterilization while minimizing chemical inputs and residues and maintaining food quality. Highly effective PAW was generated using air as a processing gas and tap water, making this a feasible and cost-effective option.

scholarly journals Successful Removal of Clostridioides Difficile Spores and Pathogenic Bacteria From a Launderable Barrier Using a Commercial Laundry Process

2020 ◽  
Vol 13 ◽  
pp. 117863372092365 ◽  
Author(s):  
Edmond Anderson Hooker ◽  
David Ulrich ◽  
Dane Brooks
Keyword(s):  
Pathogenic Bacteria ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
E Coli ◽  
Clostridioides Difficile ◽  
Mixed Suspension ◽  
Colony Forming Units ◽  
Successful Removal ◽  
Commercial Laundry ◽  
Chlorine Bleach ◽  
Wash Load

Background: To properly clean and disinfect hospital mattresses, bed manufacturers recommend a 3- to 6-step process to remove all pathogenic bacteria. An alternative is to use a removable barrier on the mattress, which is laundered after each use. The current study was to determine efficacy of a commercial laundry process in eliminating Clostridioides difficile (C diff) spores, Mycobacterium terrae (M terrae), methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa (P aeruginosa), Klebsiella pneumoniae (K pneumoniae), and Escherichia coli (E coli) from a barrier. Methods: A test barrier received 3 unique microbial suspensions in separate locations, each suspension having a known quantity of specific microorganisms: C diff spores, M terrae, and a mixed suspension of MRSA, S aureus, P aeruginosa, K pneumoniae, and E coli. A wash load contained the test barrier and 11 additional ballast barriers. Various soils were spread onto the barriers to simulate heavy soiling that may occur in a wash load: Each barrier received a small amount of mixed soil, 50% received urine, 25% received blood, and 25% received a large amount of additional mixed soil. The load was laundered using 71°C (160°F) water, detergent, and chlorine bleach, with final drying at 71°C (160°F). After laundering, remaining colony-forming units (CFUs) of each microorganism were counted at the applied locations. Each test was replicated 3 times. Industry-accepted methods were used to produce suspensions, apply inoculum, and recover organisms after laundering. Results: Before laundering, test barriers contained at least 7.0 log10 cfu/mL of each microorganism distributed over 103 cm2. After laundering, in all cases, no residual CFUs were detected over the test area, resulting in greater than 6.0 log10 reductions for every organism. ( P < .05). Conclusions: Under extreme test conditions including the presence of soil, the laundry process removed all detectable pathogenic bacteria and spores from the barrier.

scholarly journals Preharvest Transmission Routes of Fresh Produce Associated Bacterial Pathogens with Outbreak Potentials: A Review

2019 ◽  
Vol 16 (22) ◽  
pp. 4407 ◽  
Author(s):  
Chidozie Declan Iwu ◽  
Anthony Ifeanyi Okoh
Keyword(s):  
Food Safety ◽  
Pathogenic Bacteria ◽  
Fresh Produce ◽  
Treatment Options ◽  
Disease Outbreaks ◽  
Salmonella Spp ◽  
E Coli ◽  
Shigella Spp ◽  
Clinically Significant ◽  
Vegetables And Fruits

Disease outbreaks caused by the ingestion of contaminated vegetables and fruits pose a significant problem to human health. The sources of contamination of these food products at the preharvest level of agricultural production, most importantly, agricultural soil and irrigation water, serve as potential reservoirs of some clinically significant foodborne pathogenic bacteria. These clinically important bacteria include: Klebsiella spp., Salmonella spp., Citrobacter spp., Shigella spp., Enterobacter spp., Listeria monocytogenes and pathogenic E. coli (and E. coli O157:H7) all of which have the potential to cause disease outbreaks. Most of these pathogens acquire antimicrobial resistance (AR) determinants due to AR selective pressure within the agroecosystem and become resistant against most available treatment options, further aggravating risks to human and environmental health, and food safety. This review critically outlines the following issues with regards to fresh produce; the global burden of fresh produce-related foodborne diseases, contamination between the continuum of farm to table, preharvest transmission routes, AR profiles, and possible interventions to minimize the preharvest contamination of fresh produce. This review reveals that the primary production niches of the agro-ecosystem play a significant role in the transmission of fresh produce associated pathogens as well as their resistant variants, thus detrimental to food safety and public health.

Prevalence of Multidrug-Resistant Bacteria from U.S.-Grown and Imported Fresh Produce Retailed in Chain Supermarkets and Ethnic Stores of Davidson County, Tennessee

2017 ◽  
Vol 80 (3) ◽  
pp. 506-514 ◽  
Author(s):  
Siqin Liu ◽  
Agnes Kilonzo-Nthenge
Keyword(s):  
Pathogenic Bacteria ◽  
Fresh Produce ◽  
Agricultural Practices ◽  
Multidrug Resistant ◽  
Leafy Vegetables ◽  
Resistant Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Public Health Hazards

ABSTRACTThe aim of this study was to determine whether U.S.-grown and imported fresh produce retailed in ethnic stores and chain supermarkets was a reservoir of antibiotic-resistant bacteria. A total of 360 (129 imported and 231 U.S.-grown) samples of fresh produce were purchased from retail stores and analyzed for Enterobacteriaceae, including three pathogenic bacteria (Escherichia coli O157:H7, Shigella, and Salmonella), using standard methods. Presumptive pathogenic isolates were confirmed using PCR. The mean Enterobacteriaceae counts for imported produce were 6.87 ± 0.15 log CFU/g and 7.16 ± 0.11 log CFU/g in ethnic stores and chain supermarkets, respectively. For U.S.-grown produce, the contamination levels were at 8.35 ± 0.17 log CFU/g and 7.52 ± 0.13 log CFU/g in ethnic stores and chain supermarkets, respectively. Salmonella (0 and 0.3%), Shigella (1.7 and 0.6%), E. coli (3.1 and 1.4%), Enterobacter (9.4 and 8.6%), Klebsiella (6.7 and 0.6%), and Serratia (5.8 and 1.4%) were detected in produce from ethnic stores and chain supermarkets, respectively. None of the samples were positive for E. coli O157:H7. Regarding distribution by produce type, leafy vegetables had a significantly (P &lt; 0.05) higher prevalence of Enterobacteriaceae (19.2%) than the other types, followed by root vegetables (6.4%), tomatoes (5.6%), and fruits (3.9%). Antibiotic-resistant Salmonella, Shigella, E. coli, Enterobacter, Klebsiella, and Erwinia bacteria were also isolated from fresh produce. The frequencies of vancomycin resistance (98.1 and 100%) were significantly higher (P &lt; 0.05) than the frequencies of ampicillin resistance (42.3 and 72.9%) for imported and U.S.-grown produce, respectively. Despite the increased attention to the role of imported produce as a source of antimicrobial resistance, this study indicates that U.S.-grown produce is also contaminated with antibiotic-resistant bacteria. Good agricultural practices on the farms and washing of fresh produce before consumption are greatly recommended to avoid possible public health hazards.

Photocatalytically Enhanced Inactivation of Internalized Pathogenic Bacteria in Fresh Produce using Ultraviolet Irradiation with Nano-titanium Dioxide

2020 ◽  
Author(s):  
Seungjun Lee ◽  
Chulkyoon Mok ◽  
Jiyoung Lee
Keyword(s):  
Public Health ◽  
Titanium Dioxide ◽  
Food Safety ◽  
Uv Irradiation ◽  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Safety Issue ◽  
Fresh Produce ◽  
Future Research ◽  
E Coli

Once pathogens are internalized in fresh produce, they pose a challenging food safety issue since they are not effectively inactivated by conventional rinsing or sanitization. To protect food safety and public health, the objectives were to examine internalized levels of foodborne pathogens in different types of fresh produce and to investigate the effectiveness of photocatalytically enhanced inactivation of internalized pathogens in fresh produce using UV irradiation with titanium dioxide (TiO 2 ). For this, green fluorescent protein-labeled S. Typhimurium and E. coli O157:H7 were inoculated on the leaf surface of four types of fresh produce (~10 8 CFU (colony-forming unit)/leaf) and varying concentrations of TiO 2 suspension (0.50, 0.75, 1.00, 1.25, and 1.50 µg/ml)) were applied to the surface of contaminated leaves. Depending on the nature of each vegetable, the internalized bacterial level differed (log 2 – 5 CFU/g of leaf). When UV irradiation (6,000 J/m 2 ) was applied, the internalized S. Typhimurium and E. coli levels were reduced by 0.8 – 2.4 log CFU/leaf and was with TiO 2 , the reduction was 1.1 – 3.7 log CFU/leaf. The inactivation efficiency increased as the TiO 2 concentration (up to 1.50 μg/leaf). These results indicate that the TiO 2 application enhanced the photocatalytic inactivation of internalized foodborne pathogens. The application of TiO2 would be most practical before UV irradiation and before distributing the produce. This study established a platform for future research on the inactivation of various internalized pathogens for protecting public health and scaling up fresh produce treatments by the food industry.

Concentrations of Escherichia coli and Genetic Diversity and Antibiotic Resistance Profiling of Salmonella Isolated from Irrigation Water, Packing Shed Equipment, and Fresh Produce in Texas

2005 ◽  
Vol 68 (1) ◽  
pp. 70-79 ◽  
Author(s):  
E. A. DUFFY ◽  
L. M. LUCIA ◽  
J. M. KELLS ◽  
A. CASTILLO ◽  
S. D. PILLAI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Irrigation Water ◽  
Pathogenic Bacteria ◽  
Susceptibility Testing ◽  
Fresh Produce ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Element Sequence

Fresh produce has been repeatedly implicated as a vehicle in the transmission of foodborne gastroenteritis. In an effort to assess the risk factors involved in the contamination of fresh produce with pathogenic bacteria, a total of 1,257 samples were collected from cantaloupe, oranges, and parsley (both in the field and after processing) and from the environment (i.e., irrigation water, soil, equipment, etc.). Samples were collected twice per season from two production farms per commodity and analyzed for the presence of Salmonella and Escherichia coli. E. coli was detected on all types of commodities (cantaloupe, oranges, and parsley), in irrigation water, and on equipment surfaces. A total of 25 Salmonella isolates were found: 16 from irrigation water, 6 from packing shed equipment, and 3 from washed cantaloupes. Salmonella was not detected on oranges or parsley. Serotyping, pulsed-field gel electrophoresis (PFGE), and repetitive element sequence-based PCR (rep-PCR) assays were applied to all Salmonella isolates to evaluate the genetic diversity of the isolates and to determine relationships between sources of contamination. Using PFGE, Salmonella isolates obtained from irrigation water and equipment were determined to be different from cantaloupe isolates; however, DNA fingerprinting did not conclusively define relationships between contamination sources. All Salmonella isolates were subjected to antimicrobial susceptibility testing using the disk diffusion method, and 20% (5 of 25) of the isolates had intermediate sensitivity to streptomycin. One Salmonella isolate from cantaloupe was resistant to streptomycin.

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