Evaluation of PhageDX Salmonella Assay for Salmonella Detection in Hydroponic Curly Lettuce

Lettuce is one of the most consumed leafy vegetables worldwide and has been involved in multiple foodborne outbreaks. Salmonella is one of the most prevalent etiological agents of foodborne disease (FBD) in lettuces, and its detection may take several days depending on the chosen method. This study evaluates a new rapid method that uses recombinant bacteriophages to detect Salmonella in hydroponic curly lettuce. First, the ability of the assay to detect six Salmonella serovars at three different concentrations (1, 10, and 100 CFU/well) was tested. Second, the detection of Salmonella was tested in lettuces using a cocktail of the same Salmonella serovars and concentrations after a 7 h enrichment. The results of these experiments showed that the detection limit was dependent on the serovar tested. Most serovars were detected in only 2 h when the concentration was 100 CFU/well. Salmonella was detected in 9 h (7 h enrichment + 2 h bioluminescence assay) in all lettuce samples with 10 CFU/25 g or more. Salmonella detection was not influenced by natural microbiota of lettuces. This study demonstrated that the phage assay was sensitive and faster than other detection methods, indicating that it is a better alternative for Salmonella detection on lettuces.

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Isolation, Identification, and Antibiotic Susceptibility Testing of Salmonella Isolated from Foodborne Outbreaks

International Journal of Enteric Pathogens ◽

10.34172/ijep.2020.18 ◽

2020 ◽

Vol 8 (3) ◽

pp. 80-83

Author(s):

Mohammad Mehdi Soltan Dallal ◽

Milad Abdi ◽

Mahya Khalilian ◽

Zahra Rajabi ◽

Ronak Bakhtiari ◽

...

Keyword(s):

Antibiotic Resistance ◽

Antibiotic Susceptibility ◽

Salmonella Enteritidis ◽

Its Region ◽

Detection Methods ◽

Diffusion Method ◽

Antimicrobial Susceptibility Pattern ◽

Resistance Patterns ◽

Foodborne Outbreaks ◽

Salmonella Serovars

Background: Foodborne diseases are a major problem worldwide. The epidemiological investigations in many parts of the world have shown an increase in infections caused by Salmonella serovars. Furthermore, the emergence of drug resistance among them has become a major global concern and awareness of the resistance patterns of Salmonella could be very useful in treatment of diseases. Objective: This study aimed to investigate Salmonella serotypes in foodborne outbreaks by sequencing of ITS region of 16S-23SrRNA gene and to determine their antimicrobial susceptibility pattern. Materials and Methods: A total of 614 diarrheal stool samples were collected from 173 foodborne outbreaks in different provinces of Iran during one year. Identification of Salmonella was carried out by phenotypic and molecular (16s-23srRNA gene detection) methods and antibiotic susceptibility was performed using disc diffusion method. Results: Out of 614 samples, 18 isolates were identified as Salmonella of which 16 (88.9%) isolates were Salmonella Enteritidis and 2 (11.1%) isolates as Salmonella Paratyphi A. All isolates were sensitive to ceftazidime, and high resistance was seen with nalidixic acid with 14 (77.8%) isolates. Conclusion: Increasing antibiotic resistance in many bacterial pathogens such as Salmonella has been a major threat for human health. Therefore, identifying the antibiotic resistance patterns of Salmonella serovars may help in treatment of the associated infections.

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Outbreaks, Germination, and Inactivation of Bacillus cereus in Food Products: A Review

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-429 ◽

2020 ◽

Vol 83 (9) ◽

pp. 1480-1487

Author(s):

WON CHOI ◽

SANG-SOON KIM

Keyword(s):

Food Safety ◽

Bacillus Cereus ◽

Food Processing ◽

Rapid Detection ◽

Foodborne Pathogen ◽

Present Review ◽

Detection Methods ◽

Processing Technologies ◽

Foodborne Outbreaks ◽

Food Commodity

ABSTRACT Bacillus cereus has been reported as a foodborne pathogen worldwide. Although food processing technologies to inactivate the pathogen have been developed for decades, foodborne outbreaks related to B. cereus have occurred. In the present review, foodborne outbreaks, germination, inactivation, and detection of B. cereus are discussed, along with inactivation mechanisms. B. cereus outbreaks from 2003 to 2016 are reported based on food commodity, number of cases, and consequent illnesses. Germination before sporicidal treatments is highlighted as an effective way to inactivate B. cereus, because the resistance of the pathogen increases significantly following sporulation. Several germinants used for B. cereus are listed, and their efficacies are compared. Finally, recently used interventions with sporicidal mechanisms are identified, and rapid detection methods that have been developed are discussed. Combining two or more interventions, known as the hurdle technology concept, is suggested to maximize the sporicidal effect. Further study is needed to ensure food safety and to understand germination mechanisms and sporicidal resistance of B. cereus. HIGHLIGHTS

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Incubation periods of enteric illnesses in foodborne outbreaks, United States, 1998–2013

Epidemiology and Infection ◽

10.1017/s0950268819001651 ◽

2019 ◽

Vol 147 ◽

Cited By ~ 10

Author(s):

S. J. Chai ◽

W. Gu ◽

K. A. O'Connor ◽

L. C. Richardson ◽

R. V. Tauxe

Keyword(s):

United States ◽

Incubation Period ◽

Disease Outbreaks ◽

Disease Outbreak ◽

Outbreak Investigation ◽

Foodborne Disease ◽

Case Definitions ◽

Viral Pathogens ◽

Incubation Periods ◽

Foodborne Outbreaks

Abstract Early in a foodborne disease outbreak investigation, illness incubation periods can help focus case interviews, case definitions, clinical and environmental evaluations and predict an aetiology. Data describing incubation periods are limited. We examined foodborne disease outbreaks from laboratory-confirmed, single aetiology, enteric bacterial and viral pathogens reported to United States foodborne disease outbreak surveillance from 1998–2013. We grouped pathogens by clinical presentation and analysed the reported median incubation period among all illnesses from the implicated pathogen for each outbreak as the outbreak incubation period. Outbreaks from preformed bacterial toxins (Staphylococcus aureus, Bacillus cereus and Clostridium perfringens) had the shortest outbreak incubation periods (4–10 h medians), distinct from that of Vibrio parahaemolyticus (17 h median). Norovirus, salmonella and shigella had longer but similar outbreak incubation periods (32–45 h medians); campylobacter and Shiga toxin-producing Escherichia coli had the longest among bacteria (62–87 h medians); hepatitis A had the longest overall (672 h median). Our results can help guide diagnostic and investigative strategies early in an outbreak investigation to suggest or rule out specific etiologies or, when the pathogen is known, the likely timeframe for exposure. They also point to possible differences in pathogenesis among pathogens causing broadly similar syndromes.

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Microbiological Safety of Dried Spices

Annual Review of Food Science and Technology ◽

10.1146/annurev-food-030216-030000 ◽

2019 ◽

Vol 10 (1) ◽

pp. 409-427 ◽

Cited By ~ 7

Author(s):

Joshua B. Gurtler ◽

Susanne E. Keller

Keyword(s):

United States ◽

Foodborne Pathogens ◽

Bacterial Species ◽

The United States ◽

Detection Methods ◽

Product Recalls ◽

Foodborne Outbreaks ◽

Imported Food ◽

Multiple Product ◽

Pathogen Populations

Spices in the desiccated state provide an environment that allows the survival of many foodborne pathogens. Currently, the incidence of pathogen-positive spices imported into the United States is 1.9 times higher than for any other imported food. Correspondingly, imported spices have been associated with numerous foodborne outbreaks and multiple product recalls. Despite the association with recalls and outbreaks, the actual pathogen populations in spices, when found, are frequently extremely small. In addition to pathogenic bacterial species, toxigenic molds have been frequently recovered from spices, and aflatoxins have been found in as many as 58% of the spices sampled. The presence of toxigenic molds is especially problematic to the immunocompromised or those on immunosuppressive therapy and has been linked to gut aspergillosis. Numerous detection methods, including both traditional and advanced DNA regimes, are being tested to optimize recovery of pathogens from spices. Further, a number of new inactivation intervention methods to decontaminate spices are examined and discussed.

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A Nisin Bioassay Based on Bioluminescence

Applied and Environmental Microbiology ◽

10.1128/aem.65.8.3742-3745.1999 ◽

1999 ◽

Vol 65 (8) ◽

pp. 3742-3745 ◽

Cited By ~ 23

Author(s):

G. Wahlström ◽

P. E. J. Saris

Keyword(s):

Detection Limit ◽

Lactococcus Lactis ◽

Bioluminescence Assay

ABSTRACT A Lactococcus lactis subsp. lactis strain that can sense the bacteriocin nisin and transduce the signal into bioluminescence was constructed. By using this strain, a bioassay based on bioluminescence was developed for quantification of nisin, for detection of nisin in milk, and for identification of nisin-producing strains. As little as 0.0125 ng of nisin per ml was detected within 3 h by this bioluminescence assay. This detection limit was lower than in previously described methods.

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Are Staff Management Practices and Inspection Risk Ratings Associated with Foodborne Disease Outbreaks in the Catering Industry in England and Wales?

Journal of Food Protection ◽

10.4315/0362-028x-71.3.550 ◽

2008 ◽

Vol 71 (3) ◽

pp. 550-557 ◽

Cited By ~ 15

Author(s):

SARAH L. JONES ◽

SHARON M. PARRY ◽

SARAH J. O'BRIEN ◽

STEPHEN R. PALMER

Keyword(s):

Management Practices ◽

Hazard Analysis ◽

Control Point ◽

Disease Outbreaks ◽

Foodborne Disease ◽

Food Hygiene ◽

Critical Control Point ◽

Catering Industry ◽

Protective Food ◽

Foodborne Outbreaks

Despite structured enforcement of food hygiene requirements known to prevent foodborne disease outbreaks, catering businesses continue to be the most common setting for outbreaks in the United Kingdom. In a matched case control study of catering businesses, 148 businesses associated with outbreaks were compared with 148 control businesses. Hazard analysis critical control point systems and/or formal food hygiene training qualifications were not protective. Food hygiene inspection scores were not useful in predicting which catering businesses were associated with outbreaks. Businesses associated with outbreaks were more likely to be larger small and medium-sized enterprises (SMEs) or to serve Chinese cuisine and less likely to have the owner or manager working in the kitchen, but when size of the SME was taken into account these two differences were no longer significant. In larger businesses, case businesses were more likely to be hotels and were more commonly associated with viral foodborne outbreaks, but there was no explanation within the data for this association.

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Marine Toxins Detection by Biosensors Based on Aptamers

Toxins ◽

10.3390/toxins12010001 ◽

2019 ◽

Vol 12 (1) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

Wei Ye ◽

Taomei Liu ◽

Weimin Zhang ◽

Muzi Zhu ◽

Zhaoming Liu ◽

...

Keyword(s):

Detection Limit ◽

Sensitivity And Specificity ◽

High Efficiency ◽

Rapid Development ◽

High Sensitivity ◽

Detection Methods ◽

Marine Toxins ◽

Time Saving ◽

Low Detection Limit ◽

The Future

Marine toxins cause great harm to human health through seafood, therefore, it is urgent to exploit new marine toxins detection methods with the merits of high sensitivity and specificity, low detection limit, convenience, and high efficiency. Aptasensors have emerged to replace classical detection methods for marine toxins detection. The rapid development of molecular biological approaches, sequencing technology, material science, electronics and chemical science boost the preparation and application of aptasensors. Taken together, the aptamer-based biosensors would be the best candidate for detection of the marine toxins with the merits of high sensitivity and specificity, convenience, time-saving, relatively low cost, extremely low detection limit, and high throughput, which have reduced the detection limit of marine toxins from nM to fM. This article reviews the detection of marine toxins by aptamer-based biosensors, as well as the selection approach for the systematic evolution of ligands by exponential enrichment (SELEX), the aptamer sequences. Moreover, the newest aptasensors and the future prospective are also discussed, which would provide thereotical basis for the future development of marine toxins detection by aptasensors.

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Cryptosporidium and Giardia as Agents of Foodborne Disease

Journal of Food Protection ◽

10.4315/0362-028x-56.5.451 ◽

1993 ◽

Vol 56 (5) ◽

pp. 451-461 ◽

Cited By ~ 34

Author(s):

JAMES L. SMITH

Keyword(s):

Prevention And Control ◽

Life Cycles ◽

Foodborne Disease ◽

Protozoan Parasites ◽

Body Contact ◽

Chemical Agents ◽

Life Threatening ◽

Foodborne Outbreaks ◽

And Control ◽

Physical And Chemical

Infections by the protozoan parasites of the genera Cryptosporidium and Giardia can be asymptomatic or cause gastroenteritis in immunocompetent people. However, in immunocompromised individuals, the infections can be more severe and even life threatening. Both parasites are common waterborne pathogens, but on occasion they may be foodborne or transmitted by body contact. In this review, several aspects of Cryptosporidium and Giardia are discussed including their life cycles, resistance to physical and chemical agents, routes of transmission to humans, the nature of the disease caused by the parasites, and detection of the organisms in water, feces, and food. Documented incidents in which Cryptosporidium or Giardia contaminated foods were implicated as cause of gastroenteritis are discussed to illustrate conditions leading to foodborne outbreaks and to suggest means of prevention and control of the parasites when present in foods.

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Limits In Assessing Microbiological Food Safety

Journal of Food Protection ◽

10.4315/0362-028x-56.8.725 ◽

1993 ◽

Vol 56 (8) ◽

pp. 725-729 ◽

Cited By ~ 13

Author(s):

ROBERT L. BUCHANAN ◽

CATHERINE M. DEROEVER

Keyword(s):

Food Safety ◽

Food Systems ◽

Scientific Information ◽

Cost Effective ◽

Epidemiological Data ◽

Integrated Approach ◽

Detection Methods ◽

Detailed Knowledge ◽

Foodborne Disease ◽

True Incidence

Scientific information pertaining to the incidence of foodborne disease and the sources of pathogenic microorganisms is often limited in relation to the knowledge needed to make informed microbiological food safety decisions. Inherent limitations in the current epidemiological reporting system constrain its usefulness for ascertaining the true incidence of foodborne disease. Additionally, current detection methods are insufficient to make real-time decisions on the microbiological safety of products. An integrated approach that combines enhanced epidemiological data, improved detection methods, detailed knowledge of the behavior of pathogens in food systems, and development of techniques for making quantitative risk assessments is essential for the development of a comprehensive, cost-effective strategy for assuring microbiologically safe foods.

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