Recovery tests of cytopathogenic viruses from artificially contaminated food samples

2009 ◽  
Vol 1 (3) ◽  
pp. 191-194
Author(s):  
R. Zoni ◽  
R. Zanelli ◽  
S. Salsi ◽  
M. E. Colucci ◽  
G. Sansebastiano
Keyword(s):  
Food Samples ◽  
Contaminated Food

scholarly journals Listeria monocytogenes: An emerging food-borne pathogen and its public health implications

2016 ◽  
Vol 10 (02) ◽  
pp. 149-154 ◽  
Author(s):  
Waffa W Reda ◽  
Khaled Abdel-Moein ◽  
Ahmed Hegazi ◽  
Yasmin Mohamed ◽  
Khaled Abdel-Razik
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Food Samples ◽  
Food Borne ◽  
Contaminated Food ◽  
Luncheon Meat ◽  
Stool Specimens ◽  
Polymerase Chain ◽  
Minced Meat

Introduction: Listeria monocytogenes is considered one of the most important food-borne pathogens transmitted to humans via contaminated food. The aim of the present study was to demonstrate the importance of L. monocytogenes as a food-borne pathogen. Methodology: A total of 340 samples were collected from different localities in El Giza Governorate, Egypt, to check the occurrence of L. monocytogenes in that area. The collected samples comprised 250 food samples, 40 swabs from food refrigerators, and 50 stool specimens from diarrheic children. L. monocytogenes was isolated from the examined samples according to the International Organization for Standardization. The isolates were tested biochemically using Listeria Microbact 12L and confirmed by polymerase chain reaction. Results: The isolation rates of L. monocytogenes were 8% in beef burger, 4% in minced meat, 4% in luncheon meat, while sausage samples were all negative. Eight percent of raw milk samples were positive for L. monocytogenes, whereas cheese samples and refrigerator swabs were negative. Only Listeria grayi was isolated from human stools (2.5%). Conclusion: The high isolation rates of L. monocytogenes among the examined food stuffs highlight the crucial role of food as an important vehicle for this pathogen. More efforts should be made to ensure safe handling and processing of these foods to reduce the transmission of L. monocytogenes to humans.

Commercial Latex Agglutination Kits for the Detection of Food borne Salmonella

1991 ◽  
Vol 54 (9) ◽  
pp. 725-730 ◽  
Author(s):  
J.-Y. D'AOUST ◽  
A. M. SEWELL ◽  
P. GRECO
Keyword(s):  
Food Samples ◽  
Latex Agglutination ◽  
Clinical Samples ◽  
Salmonella Spp ◽  
Concurrent Use ◽  
Food Borne ◽  
Analytical Test ◽  
Contaminated Food ◽  
Pure Cultures ◽  
Vi Antigen

The ability of the Bactigen® Salmonella Shigella (BSST), the Microscreen® (MS), and the Spectate® (SPECT) latex agglutination kits to detect Salmonella in pure cultures and in naturally contaminated foods was examined. Of 190 Salmonella strains tested, the MS, BSST, and SPECT systems correctly identified 89.5, 81.6, and 66.3% of the test cultures, respectively. The sensitivity of SPECT increased to 92.7% when only strains belonging to the targeted serogroups (somatic A to E plus G) and strains harboring the Vi antigen were considered. The lack of specificity of the MS (3.4%), SPECT (17.0%), and BSST (33.9%) systems with 59 cultures of nonsalmonellae varied widely, with Citrobacter freundii and Escherichia coli accounting for many of the false-positive reactions. Examination of foods according to the prescribed MS and SPECT analytical test protocols identified respectively, 18 (75%) and 19 (79.2%) of the 24 food samples found to contain Salmonella spp. by a standard cultural method. Although instructions with the BSST kit indicate that the product is intended for the analysis of clinical samples, the system nevertheless identified 21 (87.5%) contaminated food samples under homologous MS and SPECT test conditions. The concurrent use of TBG43 with enrichment media recommended by kit manufactures enhanced the sensitivities of MS (83.3%), SPECT (91.7%), and BSST (91.7%). Attempts to effect greater method brevity through the application of latex kits at various stages of the standard cultural procedure were counterproductive.

AnDiaTec Salmonella sp. PCR-ELISA for Analysis of Food Samples

2004 ◽  
Vol 67 (8) ◽  
pp. 1585-1590 ◽  
Author(s):  
CHRISTOPH METZGER-BODDIEN ◽  
ANJA BOSTEL ◽  
JOHANNES KEHLE
Keyword(s):  
Pcr Amplification ◽  
Reference Method ◽  
Evaluation Study ◽  
Microtiter Plate ◽  
Food Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacteriological Method ◽  
Contaminated Food ◽  
Pure Cultures ◽  
Sensitivity Specificity

A commercially available PCR kit (AnDiaTec Salmonella sp. PCR-ELISA) was developed and evaluated for the detection of Salmonella sp. in food samples. The test is based on PCR amplification and hybridization of the amplified DNA to a microtiter plate followed by the detection of PCR product in the manner of an enzyme-linked immunosorbent assay test. The sensitivity and specificity were evaluated first with Salmonella pure cultures and artificially contaminated food samples, including food types for which an inhibition of the PCR reaction was expected. Both experiments proved a very good sensitivity, specificity, and reliability of the test with a very broad range of food types. In a second evaluation study, more than 1,100 food samples of different types were tested in parallel with the PCR method and with the International Standardization Organization 6579 bacteriological reference method. The results of this evaluation study and the results from other experiments on dilutions of artificially contaminated food samples led to the establishment of a positive-negative cutoff value (optical density at 450 nm of more than 0.9) with respect to the conventional bacteriological method. Using this positive-negative cutoff, 98% agreement to the bacteriological method was obtained.

scholarly journals A large common-source outbreak of norovirus gastroenteritis in a hotel in Singapore, 2012

2016 ◽  
Vol 145 (3) ◽  
pp. 535-544 ◽  
Author(s):  
P. RAJ ◽  
J. TAY ◽  
L. W. ANG ◽  
W. S. TIEN ◽  
M. THU ◽  
...  
Keyword(s):  
Food Samples ◽  
Common Source ◽  
Food Handlers ◽  
Case Control Studies ◽  
Modes Of Transmission ◽  
Norovirus Gastroenteritis ◽  
Contaminated Food ◽  
Plate Counts ◽  
Microbial Analysis ◽  
Stool Samples

SUMMARYAn outbreak of gastroenteritis affected 453 attendees (attack rate 28·5%) of six separate events held at a hotel in Singapore. Active case detection, case-control studies, hygiene inspections and microbial analysis of food, environmental and stool samples were conducted to determine the aetiology of the outbreak and the modes of transmission. The only commonality was the food, crockery and cutlery provided and/or handled by the hotel's Chinese banquet kitchen. Stool specimens from 34 cases and 15 food handlers were positive for norovirus genogroup II. The putative index case was one of eight norovirus-positive food handlers who had worked while they were symptomatic. Several food samples and remnants tested positive for Escherichia coli or high faecal coliforms, aerobic plate counts and/or total coliforms, indicating poor food hygiene. This large common-source outbreak of norovirus gastroenteritis was caused by the consumption of contaminated food and/or contact with contaminated crockery or cutlery provided or handled by the hotel's Chinese banquet kitchen.

scholarly journals Microbial food safety in Ghana: a meta-analysis

2012 ◽  
Vol 6 (12) ◽  
pp. 828-835 ◽  
Author(s):  
Courage Kosi Setsoafia Saba ◽  
Bruno Gonzalez-Zorn
Keyword(s):  
Food Safety ◽  
Meta Analysis ◽  
Food Contamination ◽  
Food Samples ◽  
Future Research ◽  
Fermented Foods ◽  
Food Research ◽  
Food Borne ◽  
Contaminated Food

Introduction: Food safety is a crucial factor in the growth of developing countries worldwide. In this study, we present a meta-analysis of microbiological food safety publications from Ghana. Methodology: The search words “Ghana food safety”, “Ghana food research”, and “Ghana food bacteria” were used to search for microbiological food safety publications with related abstracts or titles in PubMed, published between 1997 and 2009. We obtained 183 research articles, from which we excluded articles concerning ready-to-eat microbial fermented foods and waterborne microorganisms as well as articles without abstracts. The criteria used for analysis of these publications were based on an assessment of methodological soundness previously developed for use in the medical field, with some modifications incorporated. Results: The most predominant bacteria in Ghanain foods are Enterobacter spp., Citrobacter spp., Klebsiella spp. and Escherichia spp., which were found to be present in 65%, 50%, 46% and 38% respectively, of the food samples considered in the studies analysed. The most contaminated food samples were macaroni, salad, and milk. Although the methodological quality of the articles was generally sound, most of them did not give directions for future research. Several did not state possible reasons for differences between studies. Conclusion: The microbiological food contamination in Ghana is alarming. However, we found that the downward trend in publications of microbial food safety articles is appalling. Hence a concerted effort in research on food safety is needed in Ghana to help curb the incidence of preventable food-borne disease.

Enumerative Analysis of Salmonella in Outbreak-Associated Breaded and Frozen Comminuted Raw Chicken Products

2017 ◽  
Vol 80 (5) ◽  
pp. 814-818 ◽  
Author(s):  
Angela Catford ◽  
Kyle Ganz ◽  
Sandeep Tamber
Keyword(s):  
Foodborne Pathogen ◽  
Food Samples ◽  
Most Probable Number ◽  
Distribution Analysis ◽  
Probable Number ◽  
Contaminated Food ◽  
Foodborne Outbreaks ◽  
Low Levels ◽  
Data Gap ◽  
Pathogen Exposure

ABSTRACT A significant data gap exists with respect to the levels of pathogens in foods implicated in foodborne outbreaks. These data are essential for the quantification of pathogen exposure via the ingestion of contaminated food. Here we report the levels of the foodborne pathogen Salmonella in comminuted raw chicken products that had been breaded and then frozen. The products investigated were collected during four food safety investigations of foodborne outbreaks that occurred in Canada from 2014 to 2016. Most-probable-number (MPN) distribution analysis of the food samples revealed Salmonella levels of 0.0018 to 3 MPN/g, which is equivalent to 1 MPN per 0.33 to 556 g of product. These data suggest low levels of Salmonella may be associated with foodborne outbreaks.

Production and use of mycotoxins uniformly enriched with stable isotopes for their dosage in biological samples

2008 ◽  
Vol 1 (3) ◽  
pp. 275-281 ◽  
Author(s):  
F. Bravin ◽  
R. Duca ◽  
N. Loiseau ◽  
M. Pean ◽  
O. Puel ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Secondary Metabolites ◽  
Plant Biomass ◽  
Fusarium Verticillioides ◽  
Food Samples ◽  
Isotopic Cluster ◽  
Maize Seeds ◽  
Contaminated Food

Due to their low concentrations in biological matrices, mycotoxin analyses often encounter detection and quantification problems, especially for toxicokinetic studies. We have developed a strategy to produce in a single process, several fungi secondary metabolites uniformly enriched with 13C, 15N stable isotopes in their 'natural' composition. This includes: (1) a plant culture in the presence of 10%, 50% or 100% 13CO2 as the only source of carbon, and in the presence or not of 10% 15N-enriched nitrogen salts – as expected wheat or maize uniformlyincorporate enriched isotopes into their bioproducts; (2) a subsequent solid culture of different filamentous fungi on plant biomass led to the production of a 'natural' mixture of isotopes-enriched mycotoxins – these compounds exhibit a characteristic isotopic cluster, which can be easily detected by mass spectrometry. As an example, we achieved 10% uniformly 13C-enriched zearalenone, deoxynivalenol and mycophenolic acid by growing Fusarium graminearum or Penicillium brevicompactum on 10% 13C enriched wheat seeds and 3 to 10% 13C, 15N uniformly enriched fumonisins from Fusarium verticillioides cultures on maize seeds or straw. These compounds were used for metabolism and transport studies in mammals either in vitro or in vivo and analysed by MS and MSn spectra of the isotopic cluster but also by 13C, 15N NMR. Moreover, such isotopic pattern enrichment can be used for quantitative evaluations of mycotoxins transport across mammalian biological membranes, alone or in their 'natural' conditions in the presence of other fungi secondary metabolites. Finally, we used such enriched compounds with high reliabilityin order to study zearalenone metabolism but these enriched compounds would also be used as internal standards to quantify zearalenone or fumonisins in contaminated food samples.

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