Development and performance of an enzyme-linked amperometric immunosensor for the detection ofStaphylococcus aureusin foods
| Autor: | R.G. Kroll, Joy L. Brooks, B. Mirhabibollahi |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Staphylococcus aureus
Micrococcaceae Enzyme-Linked Immunosorbent Assay medicine.disease_cause Applied Microbiology and Biotechnology Microbiology Horseradish peroxidase law.invention chemistry.chemical_compound Predictive Value of Tests law medicine Staphylococcal Protein A Hydrogen peroxide Clark electrode Chromatography biology Chemistry biology.organism_classification Amperometry Catalase Food Microbiology biology.protein Protein A |
| Zdroj: | Journal of Applied Bacteriology. 68:577-585 |
| ISSN: | 0021-8847 |
| DOI: | 10.1111/j.1365-2672.1990.tb05223.x |
| Popis: | An amperometric enzyme-linked immunosensor was developed to detect and quantify levels of Staphylococcus aureus electrically in pure cultures and in foods. The assay was a modification of a 'sandwich' ELISA for the protein A of Staph. aureus, employing catalase-labelled anti-protein A antibody. On addition of hydrogen peroxide to the assay system the catalase released O2 which was monitored using an amperometric oxygen electrode. The rate of current increase was proportional to the antigen concentration (protein A or Staph. aureus). Protein A was detected reliably at 0.1 ng/ml representing a 20-fold increase in sensitivity over the conventional ELISA that used horseradish peroxidase. Pure cultures of Staph. aureus were detected at 10(-3)-10(-4) cfu/ml with the amperometric electrode (cf greater than 10(5)/ml for conventional ELISA). The same level of sensitivity was achieved for inoculated food samples. Low levels of contamination (1 cfu/g) of Staph. aureus were detected after incubation at 37 degrees C for 18 h, and the immunosensor could from the basis of a test for screening and identification of protein A-bearing Staph. aureus in 24 h, although natural variations in protein A content between different strains could make the system unreliable in accurate quantification of cell numbers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text