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EVALUATION OF PCR AND DNA HYBRIDIZATION PROTOCOLS FOR DETECTION OF VIABLE ENTEROTOXIGENIC CLOSTRIDIUM PERFRINGENS IN IRRADIATED BEEF
Author(s) -
BAEZ LUIS A.,
JUNEJA VIJAY K.,
THAYER DONALD W.,
SACKITEY SOLOMON
Publication year - 1997
Publication title -
journal of food safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 43
eISSN - 1745-4565
pISSN - 0149-6085
DOI - 10.1111/j.1745-4565.1997.tb00190.x
Subject(s) - clostridium perfringens , biology , enterotoxin , polymerase chain reaction , microbiology and biotechnology , enumeration , nucleic acid , bacteria , gene , genetics , escherichia coli , mathematics , combinatorics
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 of Clostridium 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 enterotoxigenic C. 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 of C. 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