scholarly journals AquaSparkTM – Rapid Environmental Monitoring of Listeria monocytogenes

2020 ◽  
Vol 74 (10) ◽  
pp. 791-797
Author(s):  
Giverny M. Ganz ◽  
Lukas Reinau ◽  
Anne-Flore Imhaus ◽  
Mario Hupfeld ◽  
Lars Fieseler
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Monitoring ◽  
Foodborne Pathogens ◽  
Ease Of Use ◽  
Detection Methods ◽  
Production Environment ◽  
Specificity And Sensitivity ◽  
Short Period ◽  
Food Monitoring ◽  
New Generation

In order to prevent microbial contamination of food, monitoring of the production environment, together with the rapid detection of foodborne pathogens have proven to be of utmost importance for Food Safety. Environmental monitoring should detect harmful pathogens at the earliest point in time in order for the necessary interventions to be taken. However, current detection methods fall short with regards to speed, ease of use, and cost. This article aims to present the idea behind NEMIS Technologies, a startup company making use of the novel AquaSparkTM technology for the development of a new generation of bacterial detection methods. These methods utilize chemiluminescence in order to detect live target bacteria in a short period of time compared to that of conventional methods. We show that dry-stressed Listeria monocytogenes can be detected within 24 hours, using small-molecule chemiluminescent probes, together with a bacteria-specific proprietary enrichment broth containing a cocktail of bacteriophages, which enhance the specificity and sensitivity. This novel platform technology has the potential to extend beyond environmental monitoring towards food analyses as well as veterinary and human health.

Specificity of the BAX Polymerase Chain Reaction System for Detection of the Foodborne Pathogen Listeria monocytogenes

1998 ◽  
Vol 81 (4) ◽  
pp. 817-822 ◽  
Author(s):  
Diana Stewart ◽  
Steven M Gendel
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Foodborne Pathogen ◽  
Reaction System ◽  
Chain Reaction ◽  
Mixed Cell ◽  
Specificity And Sensitivity ◽  
Colony Forming Units ◽  
Polymerase Chain

Abstract The polymerase chain reaction (PCR) can be used for rapid and specific detection of foodborne pathogens. One commercial kit, the Qualicon BAX system uses PCR to detect Listeria monocytogenes in enrichment cultures derived from food and environmental samples. The specificity and sensitivity of the BAX system for detecting L. monocytogenes were characterized by using both pure and mixed cell cultures, and optimal conditions for production of cell lysates were determined. The BAX system was highly specific for L. monocytogenes, and no interference was seen in the presence of either other Listeria species or microbes from other genera. The assay detected L. monocytogenes at 105- 106 colony-forming units/mL. This sensitivity is adequate for detecting viable cells after enrichment but prevents false-positive signals from nonviable cells.

A Comparison of Three Methods for the Isolation of Arcobacter spp. from Retail Raw Poultry in Northern Ireland

2004 ◽  
Vol 67 (4) ◽  
pp. 799-804 ◽  
Author(s):  
ROISIN SCULLION ◽  
CLARE S. HARRINGTON ◽  
ROBERT H. MADDEN
Keyword(s):  
Northern Ireland ◽  
Foodborne Pathogens ◽  
Membrane Filtration ◽  
Ease Of Use ◽  
Detection Methods ◽  
Modified Method ◽  
Antibiotic Cocktail ◽  
The Difference ◽  
Filtration Step ◽  
Raw Poultry

Recent evidence suggests that arcobacters, especially Arcobacter butzleri, are potential foodborne pathogens, but standardized detection methods have yet to be established. A study was undertaken to determine which of three isolation methods was the most effective for the isolation of Arcobacter spp. from fresh raw poultry. Method 1 was microaerobic and involved a membrane filtration step followed by plating onto blood agar. Method 2 was also microaerobic and involved enrichment and plating media containing a five-antibiotic cocktail. Method 3 was aerobic and was based on enrichment in a charcoal-based broth containing two antibiotics. Retail poultry samples (n = 50) were obtained from supermarkets in Northern Ireland; the European Community license number was recorded to ensure sample diversity. Presumptive arcobacters were identified using genus-speci c and species-speci c primers. Method 1 resulted in the lowest recovery of arcobacters (28% of samples positive). The detection rate for method 2 (68%) was higher than that for method 3 (50%), but the difference was not significant (P > 0.05). Modification of method 3 by plating the enrichment broth at 24 h, as well as at 48 h, increased recovery to 68%. Use of methods 2 and 3 together increased the number of positive samples detected by approximately 25% compared with use of either method alone. A. butzleri was the most commonly isolated species using all methods. Method 3 detected Arcobacter cryaerophilus in more samples (n = 3) than did methods 1 and 2 (n = 1). Arcobacter skirrowii was detected by only method 3 (n = 1). In terms of sensitivity, ease of use, and diversity of species recovered, modified method 3 was the overall method of choice.

scholarly journals Review of analytical performance of COVID-19 detection methods

2020 ◽  
Author(s):  
Basant Giri ◽  
Shishir Pandey ◽  
Retina Shrestha ◽  
Krisha Pokharel ◽  
Frances S. Ligler ◽  
...  
Keyword(s):  
Public Health ◽  
Limit Of Detection ◽  
Clinical Decision ◽  
Ease Of Use ◽  
Diagnostic Methods ◽  
Analytical Performance ◽  
Detection Sensitivity ◽  
Detection Methods ◽  
Infected People ◽  
Short Period

Abstract In the recent SARS-CoV-2 pandemic, public health experts have emphasized testing, tracking infected people, and tracing their contacts as an effective strategy to reduce the spread of the virus. Several diagnostic methods are reported for detecting the coronavirus in clinical, research, and public health laboratories. Some tests detect the infection directly by detecting the viral RNA and other tests detect the infection indirectly by detecting the host antibodies. A diagnostic test during the pandemic should help make an appropriate clinical decision in a short period of time. Recently reported diagnostic methods for SARS-CoV-2 have varying throughput, batching capacity, requirement of infrastructure setting, analytical performance, and turnaround times ranging from a few minutes to several hours. These factors should be considered while selecting a reliable and rapid diagnostic method to help make an appropriate decision and prompt public health interventions. This paper reviews recent SARS-CoV-2 diagnostic methods published in journals and reports released by regulatory agencies. We compared the analytical efficiency including limit of detection, sensitivity, specificity, and throughput. In addition, we also looked into ease of use, affordability, and availability of accessories. Finally, we discuss the limitations of the methods and provide our perspectives on priorities for future test development.

Development, Popularization and Application of An Online OvAge Calculator: Qualitative Study Based on the WeChat Mini Program (Preprint)

2020 ◽  
Author(s):  
Wenwen Xu ◽  
Hui Wang ◽  
Zheng Zhu ◽  
Quan Wang ◽  
Jing Jin ◽  
...  
Keyword(s):  
Predictive Model ◽  
Ovarian Reserve ◽  
Chinese Women ◽  
Polycystic Ovary ◽  
Statistical Significance ◽  
Clinical Samples ◽  
Clinical Markers ◽  
Clinical Trial Registry ◽  
Specificity And Sensitivity ◽  
Short Period

BACKGROUND At present, there are many clinical markers and models to assess ovarian reserve, but none of them are ideal. The number of clinical samples is a key factor limiting the specificity and sensitivity of the markers and models, and traditional methods of subject recruitment are time and vigor. In addition, the model of ovarian reserve assessment for Chinese women need to be further explored. OBJECTIVE To explore the possibility of self-reporting for subjects through the WeChat mini program, and provide more data support for further optimization of the OvAge model, and to develop a predictive model of ovarian reserve that is specific to Chinese women. METHODS In this paper, with reference to the existing OvAge model, we developed an online OvAge calculator based on the WeChat mini program for data collection, and then applied the generalized linear model theory to obtain a predictive model of ovarian reserve which is in line with the characteristics of Chinese women. RESULTS Compared to traditional recruiting methods, the online OvAge calculator is able to collect a large number of samples in a short period of time, which is efficient and convenient. Optimized model of estimated OvAge =exp (3.5254-0.001*PRL-0.0231*AMH). This model showed a high statistical significance for each marker included in the equation. We applied the final equation on diminished ovarian reserve and polycystic ovary syndrome datasets and obtained a mean of predicted ovarian age significantly different from the mean of chronological age in both groups. CONCLUSIONS The OvAge calculator based on the WeChat mini program is a novel online subject self-reporting system that can collect many samples in a short period of time, continuously optimize the model and update the mini program version, which is economical, time-saving and efficient., and is worthy of promotion. In addition, the optimized OvAge model is suitable for Chinese women and provides a reference for clinical assessment of ovarian reserve. CLINICALTRIAL The study was approved by Chinese Clinical Trial Registry (registration No. ChiCTR2000037522) and Medical ethics committee of Jiangsu Province Hospital of Chinese Medicine (approved No. 2019NL-152-02).

scholarly journals Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4916 ◽  
Author(s):  
Qiaoyun Wu ◽  
Yunzhe Zhang ◽  
Qian Yang ◽  
Ning Yuan ◽  
Wei Zhang
Keyword(s):  
Pathogen Detection ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Ease Of Use ◽  
Detection Methods ◽  
Future Research ◽  
Dna Biosensors ◽  
Food Borne Pathogens ◽  
Chip Technology ◽  
Food Borne

The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).

Application of the SureTect Detection Methods for Listeria monocytogenes and Listeria spp. in Meat, Dairy, Fish, and Vegetable Products

2014 ◽  
Vol 8 (1) ◽  
pp. 1-6 ◽  
Author(s):  
David Rodriguez-Lazaro ◽  
Patricia Gonzalez-García ◽  
Antonio Valero ◽  
Marta Hernandez
Keyword(s):  
Listeria Monocytogenes ◽  
Detection Methods ◽  
Vegetable Products

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

2016 ◽  
Vol 79 (7) ◽  
pp. 1143-1153 ◽  
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.

Evaluation of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Yeasts and Molds on Fresh and Fresh-Cut Produce

2005 ◽  
Vol 68 (6) ◽  
pp. 1176-1187 ◽  
Author(s):  
KAYE V. SY ◽  
MELINDA B. MURRAY ◽  
M. DAVID HARRISON ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
Gaseous Chlorine Dioxide ◽  
Sensory Qualities ◽  
A Cell ◽  
Fresh Cut ◽  
Yeasts And Molds

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

scholarly journals Use of multi-locus sequencing typing as identification method for the food-borne pathogen Listeria monocytogenes: a review

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sonia Lamon ◽  
Domenico Meloni ◽  
Simonetta Gianna Consolati ◽  
Anna Mureddu ◽  
Rina Mazzette
Keyword(s):  
Listeria Monocytogenes ◽  
Detection Methods ◽  
Causative Organism ◽  
Intracellular Pathogen ◽  
Bacterial Strains ◽  
New Approach ◽  
Food Borne ◽  
Global Epidemiology ◽  
Selection Of

<em>Listeria monocytogenes</em> is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in several outbreaks of foodborne diseases. In this review, a new approach to molecular typing primarily designed for global epidemiology has been described: multi-<em>locus</em> sequencing typing (MLST). This approach is novel, in that it uses data that allow the unambiguous characterization of bacterial strains via the Internet. Our aim is to present the currently available selection of references on <em>L. monocytogenes</em> MLST detection methods and to discuss its use as <em>gold</em> <em>standard</em> to <em>L. monocytogenes</em> subtyping method.

Sign in / Sign up

Export Citation Format

Share Document