Efficacy of Three Light Technologies for Reducing Microbial Populations in Liquid Suspensions

The aim of the current study was to evaluate the effectiveness of three nonthermal light technologies (NUV-Vis, continuous UV, and HILP) on their ability to inactivateEscherichia coliK12 andListeria innocua. E. coliK12 was selected as a representative microorganism for the enterohaemorrhagic foodborne pathogenE. coliO157:H7 andL. innocuaas a surrogate microorganism for the common foodborne pathogenListeria monocytogenes, respectively. The liquid matrix used for the disinfection experiments was a liquid matrix (MRD solution). The results of the present study show that the HILP treatment inactivated bothE. coliandL. innocuamore rapidly and effectively than either continuous UV-C or NUV-vis treatment. With HILP at 2.5 cm from the lamp,E. coliandL. innocuapopulations were reduced by 3.07 and 3.77 log10CFU/mL, respectively, after a 5 sec treatment time, and were shown to be below the limit of detection (<0.22 log10CFU/mL) following 30 sec exposure to HILP (106.2 J/cm2). These studies demonstrate the bactericidal efficacy of alternative nonthermal light technologies and their potential as decontamination strategies in the food industry.

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Preventing Foodborne Illness: E. coli O157:H7

EDIS ◽

10.32473/edis-fs097-2017 ◽

2020 ◽

Vol 2017 (2) ◽

pp. 7

Author(s):

Keith R. Schneider ◽

Renée Goodrich Schneider ◽

Ploy Kurdmongkoltham ◽

Bruna Bertoldi

Keyword(s):

Foodborne Pathogen ◽

Foodborne Illness ◽

Human Nutrition ◽

Food Science ◽

Food Handlers ◽

E Coli ◽

Fact Sheet ◽

The Common

This seven-page fact sheet discusses the common foodborne pathogen E. coli O157:H7, especially as it concerns food handlers, processors and retailers. Written by Keith R. Schneider, Renée Goodrich Schneider, Ploy Kurdmongkoltham, and Bruna Bertoldi and published by the Food Science and Human Nutrition Department.http://edis.ifas.ufl.edu/fs097 Previous versions: Schneider, Keith, Renée Goodrich-Schneider, Alexandra Chang, and Susanna Richardson. 2013. “Preventing Foodborne Illness: E. Coli O157:H7”. EDIS 2013 (9). https://journals.flvc.org/edis/article/view/121180. Schneider, Keith, Renée Goodrich-Schneider, Michael Hubbard, and Alexandra Chang. 2009. “Preventing Foodborne Illness: E. Coli O157:H7”. EDIS 2009 (10). https://journals.flvc.org/edis/article/view/118205. Schneider, Keith, Renée Goodrich, and Melissa Kirby. 1. “Preventing Foodborne Illness: E. Coli O157:H7”. EDIS 2003 (3). https://journals.flvc.org/edis/article/view/108642.

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Monitoring the Microbial Populations and Temperatures of Fresh Broccoli from Harvest to Retail Display†

Journal of Food Protection ◽

10.4315/0362-028x-69.5.1118 ◽

2006 ◽

Vol 69 (5) ◽

pp. 1118-1125 ◽

Cited By ~ 19

Author(s):

R. DALLAIRE ◽

D. I. LeBLANC ◽

C. C. TRANCHANT ◽

L. VASSEUR ◽

P. DELAQUIS ◽

...

Keyword(s):

Distribution System ◽

Limit Of Detection ◽

Fecal Coliforms ◽

Microbial Populations ◽

Most Probable Number ◽

Probable Number ◽

E Coli ◽

Production And Distribution ◽

Experimental Variability ◽

Retail Display

Microbial populations and the temperature of fresh broccoli were monitored at several steps of a supply chain by sampling 33 distinct lots of locally grown produce over two seasons during harvest, storage, wholesale handling, and retail display. Imported broccoli was also sampled, but only at retail display. Microbiological analyses were conducted on the florets of 201 local and 60 imported broccoli samples to determine populations of total aerobic bacteria (aerobic colony count), fecal coliforms, Escherichia coli, and Listeria monocytogenes. All the samples had mean aerobic colony counts ranging between 4 and 6 log CFU/g, but L. monocytogenes was not detected (limit of detection = 100 CFU/g). Fecal coliforms and E. coli (limit of detection = 20 most probable number per 100 g) were found in 22 of 126 samples of local broccoli collected at various steps of the production and distribution system during the first season. None was found in 75 samples collected in the second season. Fecal coliforms and E. coli were found in 2 of 60 imported broccoli samples. Broccoli temperatures were relatively well controlled throughout the production and distribution system. No clear change in produce microbial populations was evident between harvest and retail display, during both sampling seasons. However, a large experimental variability was found, possibly associated with the high variability of the initial levels of microbial populations on broccoli at harvest.

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Total Coliform and Generic E. coli Levels, and Salmonella Presence in Eight Experimental Aquaponics and Hydroponics Systems: A Brief Report Highlighting Exploratory Data

Horticulturae ◽

10.3390/horticulturae6030042 ◽

2020 ◽

Vol 6 (3) ◽

pp. 42

Author(s):

Daniel L. Weller ◽

Lauren Saylor ◽

Paula Turkon

Keyword(s):

Limit Of Detection ◽

Foodborne Pathogen ◽

Total Coliform ◽

Most Probable Number ◽

Probable Number ◽

E Coli ◽

Circulating Water ◽

Two Samples ◽

Pathogen Prevalence ◽

Hydroponic Systems

Although many studies have investigated foodborne pathogen prevalence in conventional produce production environments, relatively few have investigated prevalence in aquaponics and hydroponics systems. This study sought to address this knowledge gap by enumerating total coliform and generic E. coli levels, and testing for Salmonella presence in circulating water samples collected from five hydroponic systems and three aquaponic systems (No. of samples = 79). While total coliform levels ranged between 6.3 Most Probable Number (MPN)/100-mL and the upper limit of detection (2496 MPN/100-mL), only three samples had detectable levels of E. coli and no samples had detectable levels of Salmonella. Of the three E. coli positive samples, two samples had just one MPN of E. coli/100-mL while the third had 53.9 MPN of E. coli/100-mL. While the sample size reported here was small and site selection was not randomized, this study adds key data on the microbial quality of aquaponics and hydroponics systems to the literature. Moreover, these data suggest that contamination in these systems occurs at relatively low-levels, and that future studies are needed to more fully explore when and how microbial contamination of aquaponics and hydroponic systems is likely to occur.

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

SLAS TECHNOLOGY Translating Life Sciences Innovation ◽

10.1177/2472630320981935 ◽

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.

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Predicting the bactericidal efficacy of solar disinfection (SODIS): from kinetic modeling of in vitro tests towards the in silico forecast of E. coli inactivation

Chemical Engineering Journal ◽

10.1016/j.cej.2021.130866 ◽

2021 ◽

pp. 130866

Author(s):

Sofia Samoili ◽

Giulio Farinelli ◽

José Ángel Moreno-SanSegundo ◽

Kevin G. McGuigan ◽

Javier Marugán ◽

...

Keyword(s):

Kinetic Modeling ◽

In Silico ◽

In Vitro Tests ◽

Solar Disinfection ◽

E Coli ◽

Bactericidal Efficacy

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Correlation Between Intestinal Microflora and Gastrointestinal Dysfunction in Elderly Patients with Sepsis

Nanoscience and Nanotechnology Letters ◽

10.1166/nnl.2020.3206 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1030-1037

Author(s):

Hailing Yang ◽

Xiaolin Zhang ◽

Weijun Chen ◽

Libo Shang ◽

Bin Chen ◽

...

Keyword(s):

Elderly Patients ◽

Intestinal Microflora ◽

Sepsis Group ◽

Control Group ◽

Gastrointestinal Dysfunction ◽

E Coli ◽

Significant Difference ◽

Prevention And Treatment ◽

The Common ◽

Wbc Count

Multiple organ dysfunction syndrome (MODS) is a key factor that leads to death in elderly patients with sepsis. Therefore, early prevention and treatment of gastrointestinal dysfunction (GIDF) in elderly patients with sepsis is an important measure to prevent MODS occurrence. This research explores the correlation between intestinal microflora and GIDF in elderly patients with sepsis and provides ideas for the prevention and treatment of GIDF in elderly patients with sepsis. In this study, 152 patients with sepsis (122 patients with sepsis and GIDF) treated in the Third Affiliated Hospital of Yunnan University of Chinese Medicine from January to September 2019 were selected as the sepsis group and 100 elderly who had normal physical examination results were selected as the control group. The common intestinal microflora of the two groups was compared. Patients with sepsis and GIDF were treated as the GIDF group and the other patients with sepsis were treated as the non-GIDF group. The common intestinal microflora, gastrointestinal indicators, serum inflammatory factors, and immune function indices were compared between the two groups. Correlation analysis of the observed indices with statistical significance was carried out. The results showed 152 patients with sepsis and 122 patients with sepsis and GIDF; thus, the incidence of sepsis with GIDF was 80.26%. The total average score of sepsis with GIDF was 3.61±0.09. There was no statistically significant difference in GIDF scores of patients ages 65–75 and > 75 years old. The number of Bifidobacterium and Lactobacillus in elderly patients with sepsis was lower and the number of Escherichia coli was higher than in the control group. In elderly patients with sepsis, the number of Bifidobacterium and Lactobacillus in the GIDF group was lower and the number of E. coli was higher than in the non-GIDF group. White blood cell (WBC) count, procalcitonin (PCT), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), gastrin (GAS), and diamine oxidase (DAO) in GIDF patients were higher and motilin (MOT), CIT (CIT), CD4+, and CD8+ were lower than in the non-GIDF group. WBC count, PCT, CRP, TNF-α, GAS, and DAO were negatively correlated with the number of Bifidobacterium and Lactobacillus but positively correlated with E. coli. MOT, CIT, CD4+, and CD8+ were positively correlated with the number of Bifidobacterium and Lactobacillus but negatively correlated with E. coli. There was a negative correlation between Bifidobacterium and Lactobacillus and GIDF score and a positive correlation between E. coli and GIDF score. Therefore, the change in the intestinal microflora in elderly patients with sepsis is related to GIDF.

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Changes in Aerobic Plate and Escherichia coli–Coliform Counts and in Populations of Inoculated Foodborne Pathogens on Inshell Walnuts during Storage

Journal of Food Protection ◽

10.4315/0362-028x.jfp-15-553 ◽

2016 ◽

Vol 79 (7) ◽

pp. 1143-1153 ◽

Cited By ~ 8

Author(s):

JOHN C. FRELKA ◽

GORDON R. DAVIDSON ◽

LINDA J. HARRIS

Keyword(s):

Escherichia Coli ◽

Listeria Monocytogenes ◽

Relative Humidity ◽

Low Temperature ◽

Foodborne Pathogens ◽

Limit Of Detection ◽

Sampling Time ◽

E Coli ◽

Plate Counts ◽

Forced Air

ABSTRACT After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P > 0.05) or decreased by <0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (~8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of −0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by −0.17 log CFU per nut per month and −0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent sampling time by either plating or by enrichment.

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A Comparison of Hand Washing Techniques To Remove Escherichia coli and Caliciviruses under Natural or Artificial Fingernails

Journal of Food Protection ◽

10.4315/0362-028x-66.12.2296 ◽

2003 ◽

Vol 66 (12) ◽

pp. 2296-2301 ◽

Cited By ~ 45

Author(s):

CHIA-MIN LIN ◽

FONE-MAO WU ◽

HOI-KYUNG KIM ◽

MICHAEL P. DOYLE ◽

BARRY S. MICHAELS ◽

...

Keyword(s):

Escherichia Coli ◽

Tap Water ◽

Hand Washing ◽

Microbial Populations ◽

Liquid Soap ◽

E Coli ◽

Hand Sanitizer ◽

Before And After ◽

Escherichia Coli Jm109 ◽

Viral Indicators

Compared with other parts of the hand, the area beneath fingernails harbors the most microorganisms and is most difficult to clean. Artificial fingernails, which are usually long and polished, reportedly harbor higher microbial populations than natural nails. Hence, the efficacy of different hand washing methods for removing microbes from natural and artificial fingernails was evaluated. Strains of nonpathogenic Escherichia coli JM109 and feline calicivirus (FCV) strain F9 were used as bacterial and viral indicators, respectively. Volunteers with artificial or natural nails were artificially contaminated with ground beef containing E. coli JM109 or artificial feces containing FCV. Volunteers washed their hands with tap water, regular liquid soap, antibacterial liquid soap, alcohol-based hand sanitizer gel, regular liquid soap followed by alcohol gel, or regular liquid soap plus a nailbrush. The greatest reduction of inoculated microbial populations was obtained by washing with liquid soap plus a nailbrush, and the least reduction was obtained by rubbing hands with alcohol gel. Lower but not significantly different (P > 0.05) reductions of E. coli and FCV counts were obtained from beneath artificial than from natural fingernails. However, significantly (P ≤ 0.05) higher E. coli and FCV counts were recovered from hands with artificial nails than from natural nails before and after hand washing. In addition, microbial cell numbers were correlated with fingernail length, with greater numbers beneath fingernails with longer nails. These results indicate that best practices for fingernail sanitation of food handlers are to maintain short fingernails and scrub fingernails with soap and a nailbrush when washing hands.

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Reduction of Microorganisms on Citrus Fruit Surfaces during Packinghouse Processing

Journal of Food Protection ◽

10.4315/0362-028x-61.7.903 ◽

1998 ◽

Vol 61 (7) ◽

pp. 903-906 ◽

Cited By ~ 39

Author(s):

STEVEN PAO ◽

G. ELDON BROWN

Keyword(s):

Test Organism ◽

Citrus Fruit ◽

Microbial Populations ◽

Most Probable Number ◽

Probable Number ◽

E Coli ◽

Plate Counts ◽

High Level ◽

Inoculation Study ◽

Fruit Surface

Citrus fruit surface microbial populations were evaluated following various packingline processes of seven Florida commercial packinghouses. At each packinghouse, six fruits (oranges or tangerines) were collected at each of four sampling points. The sampling was conducted in duplicate; thus, 336 fruit were evaluated during this survey. Average aerobic plate counts and yeast and mold counts on fruit surfaces before washing were about 4.0 log CFU/cm2 and 3.3 log CFU/cm2, respectively, and were reduced to 2.1 log CFU/cm2 and 1.3 log CFU/cm2, respectively, by packinghouse processing. Waxing alone reduced the average fruit surface aerobic plate counts and coliform counts from 3.7 log CFU/cm2 and 35.2 most probable number (MPN)/cm2, respectively, to 2.6 log CFU/cm2 and 1.4 MPN/cm2. No Escherichia coli was recovered from fruit at the end of packinghouse processing, and no salmonellae were found on fruit during the entire processing. In an inoculation study to test the effect of packinghouse processes, test organism E. coli was applied to fruit to achieve a high level (4.8 log CFU/cm2) of contamination. The average E. coli count was reduced about 2.4 log cycles by washing and rinsing with potable water (40 psi, 25 °C) for about 30 s. The combination of washing and waxing significantly reduced the inoculated level of E. coli from 4.8 to 1.4 log CFU/cm2.

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Development of an Immunoassay for Detection of Staphylococcal Enterotoxin-Like J, A Non-Characterized Toxin

Toxins ◽

10.3390/toxins10110458 ◽

2018 ◽

Vol 10 (11) ◽

pp. 458 ◽

Cited By ~ 1

Author(s):

Hisaya Ono ◽

Nobuaki Hachiya ◽

Yasunori Suzuki ◽

Ikunori Naito ◽

Shouhei Hirose ◽

...

Keyword(s):

Limit Of Detection ◽

Expression System ◽

Sandwich Elisa ◽

Food Poisoning ◽

High Sensitivity ◽

Enzyme Linked Immunosorbent Assay ◽

E Coli ◽

Detection Systems ◽

C Terminus ◽

Culture Supernatants

Staphylococcal enterotoxins (SEs) are the cause of staphylococcal food poisoning (SFP) outbreaks. Recently, many new types of SEs and SE-like toxins have been reported, but it has not been proved whether these new toxins cause food poisoning. To develop an immunoassay for detection of SE-like J (SElJ), a non-characterized toxin in SFP, a mutant SElJ with C-terminus deletion (SElJ∆C) was expressed and purified in an E. coli expression system. Anti-SElJ antibody was produced in rabbits immunized with the SElJ∆C. Western blotting and sandwich enzyme-linked immunosorbent assay (ELISA) detection systems were established and showed that the antibody specifically recognizes SElJ without cross reaction to other SEs tested. The limit of detection for the sandwich ELISA was 0.078 ng/mL, showing high sensitivity. SElJ production in S. aureus was detected by using the sandwich ELISA and showed that selj-horboring isolates produced a large amount of SElJ in the culture supernatants, especially in that of the strain isolated from a food poisoning outbreak in Japan. These results demonstrate that the immunoassay for detection of SElJ is specific and sensitive and is useful for determining the native SElJ production in S. aureus isolated from food poisoning cases.

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