| Autor: |
BAEZ, LUIS A., JUNEJA, VIJAY K., THAYER, DONALD W., SACKITEY, SOLOMON |
| Zdroj: |
Journal of Food Safety; December 1997, Vol. 17 Issue: 4 p229-238, 10p |
| Abstrakt: |
The sensitivity of DNA hybridization and polymerase chain reaction (PCR), was evaluated in irradiated cooked and raw beef samples. A membrane‐based colony hybridization assay and a PCR protocol, both with specificity for the enterotoxin A gene ofClostridium perfringens, were compared with viable plate counts. The results of the colony hybridization procedure were in agreement with viable plate counts for detection and enumeration of enterotoxigenicC. perfringens. The PCR procedure combined a 4 h enrichment followed by a nucleic acid extraction step and assessed the amplification of 183 and 750 base pair enterotoxin gene targets. Detection ofC. perfringens by PCR did not show a reliable correlation with viable plate counts or the colony hybridization assay. C. perfringens killed by irradiation were not detected by the plate count or colony hybridization methods; however, killed cells were detected with the PCR technique. By relying on the growth of viable cells for detection and/or enumeration, the colony hybridization and plate count methods provided a direct correlation with the presence of viable bacteria.; Accepted for Publication August 6, 1997 |
| Databáze: |
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