The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform

Joel Grout - One of the best experts on this subject based on the ideXlab platform.

  • comparison between a pcr elisa test and the vero Cell Assay for detecting shiga toxin producing escherichia coli in dairy products and characterization of virulence traits of the isolated strains
    Journal of Applied Microbiology, 2001
    Co-Authors: Patrick Fach, Francoise Dilasser, Sylvie Perelle, Joel Grout
    Abstract:

    Aims: This paper provides information on a PCR-ELISA method for detecting Shiga toxin-producing Escherichia coli (STEC), and on their prevalence in dairy products. Methods and Results: The sensitivity and specificity of the test was evaluated using pure cultures, spiked and naturally-contaminated samples. A comparative study with vero cytotoxicity testing was conducted, and STEC isolated from naturally-contaminated samples were characterized. The PCR-ELISA test was highly specific and sensitive, and detected 14% more positive samples than the vero Cell Assay. The prevalence of STEC in raw milk and unpasteurized cheese was 21·5% and 30·5%, respectively, while samples from the ‘dairy environment’ and from pasteurized cheese were less contaminated. The 34 strains of STEC isolated from natural samples showed that some of them carried virulence genes. Conclusions: No conclusion can be drawn at the moment concerning the potential risk to consumers. Significance and Impact of the Study: These data show the necessity of valuable screening methods to appreciate the virulence of STEC.

Charles Weissmann - One of the best experts on this subject based on the ideXlab platform.

  • Assaying prions in Cell culture: the standard scrapie Cell Assay (SSCA) and the scrapie Cell Assay in end point format (SCEPA).
    Methods in molecular biology (Clifton N.J.), 2008
    Co-Authors: Sukhvir P. Mahal, Cheryl A. Demczyk, Emery Smith, Peter-christian Klöhn, Charles Weissmann
    Abstract:

    Prions are usually quantified by bioAssays based on intracerebral inoculation of animals, which are slow, imprecise, and costly. We have developed a Cell-based prion Assay that is based on the isolation of Cell lines highly susceptible to certain strains (Rocky Mountain Laboratory and 22L) of mouse prions and a method for identifying individual, prion-infected Cells and quantifying them. In the standard scrapie Cell Assay (SSCA), susceptible Cells are exposed to prion-containing samples for 4 days, grown to confluence, passaged two or three times, and the proportion of rPrP(Sc)-containing Cells is determined with automated counting equipment. The dose response is dynamic over 2 logs of prion concentrations. The SSCA has a standard error of +/-20-30%, is as sensitive as the mouse bioAssay, 10 times faster, at least 2 orders of magnitude less expensive, and it is suitable for robotization. Assays performed in a more time-consuming end point titration format extend the sensitivity and show that infectivity titers measured in tissue culture and in the mouse are similar.

Debbie Mckenzie - One of the best experts on this subject based on the ideXlab platform.

  • The Standard Scrapie Cell Assay: Development, Utility and Prospects
    Viruses, 2015
    Co-Authors: Jacques Van Der Merwe, Judd M. Aiken, David Westaway, Debbie Mckenzie
    Abstract:

    Prion diseases are a family of fatal neurodegenerative diseases that involve the misfolding of a host protein, PrPC. Measuring prion infectivity is necessary for determining efficacy of a treatment or infectivity of a prion purification procedure; animal bioAssays are, however, very expensive and time consuming. The Standard Scrapie Cell Assay (SSCA) provides an alternative approach. The SSCA facilitates quantitative in vitro analysis of prion strains, titres and biological properties. Given its robust nature and potential for high throughput, the SSCA has substantial utility for in vitro characterization of prions and can be deployed in a number of settings. Here we provide an overview on establishing the SSCA, its use in studies of disease dissemination and pathogenesis, potential pitfalls and a number of remaining challenges.

Patrick Fach - One of the best experts on this subject based on the ideXlab platform.

  • comparison between a pcr elisa test and the vero Cell Assay for detecting shiga toxin producing escherichia coli in dairy products and characterization of virulence traits of the isolated strains
    Journal of Applied Microbiology, 2001
    Co-Authors: Patrick Fach, Francoise Dilasser, Sylvie Perelle, Joel Grout
    Abstract:

    Aims: This paper provides information on a PCR-ELISA method for detecting Shiga toxin-producing Escherichia coli (STEC), and on their prevalence in dairy products. Methods and Results: The sensitivity and specificity of the test was evaluated using pure cultures, spiked and naturally-contaminated samples. A comparative study with vero cytotoxicity testing was conducted, and STEC isolated from naturally-contaminated samples were characterized. The PCR-ELISA test was highly specific and sensitive, and detected 14% more positive samples than the vero Cell Assay. The prevalence of STEC in raw milk and unpasteurized cheese was 21·5% and 30·5%, respectively, while samples from the ‘dairy environment’ and from pasteurized cheese were less contaminated. The 34 strains of STEC isolated from natural samples showed that some of them carried virulence genes. Conclusions: No conclusion can be drawn at the moment concerning the potential risk to consumers. Significance and Impact of the Study: These data show the necessity of valuable screening methods to appreciate the virulence of STEC.

Bradley D Preston - One of the best experts on this subject based on the ideXlab platform.