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A 16S rDNA-based PCR method for rapid and specific detection of Clostridium perfringens in food
R F Wang1, W W Cao, W Franklin
1Microbiology Division, National Center for Toxicological Research, FDA, Jefferson, AR 72079.
Abstract:
A 16S rDNA-based polymerase chain reaction (PCR) method was developed for the rapid and specific detection of Clostridium perfringens in food. The PCR primers were designed by a GenBank computer search and they are complementary only with the 16S rRNA gene of C. perfringens by sequence alignment. The PCR product is a 279 BP DNA fragment. All C. perfringens strains tested were positive in the PCR assay and all other species tested were negative, including 11 other species of Clostridium and 38 species of other common bacteria. As few as two cells of C. perfringens in pure culture were detectable. High numbers of other bacterial species did not interfere with the detection of C. perfringens. The PCR amplification required only 30 min to complete. The method can be used for detection of C. perfringens in contaminated food. Samples from 100 g of chicken drumsticks which were inoculated with 20, 200 or 2000 cells of C. perfringens were subjected to the PCR assay and all produced positive results.
Insights
A new polymerase chain reaction (PCR) method accurately detects Clostridium perfringens in food. This rapid test identifies the bacterium even at low levels, ensuring food safety.
Area of Science:
- Microbiology
- Food Science
- Molecular Biology
Background:
- Clostridium perfringens is a common cause of foodborne illness.
- Accurate and rapid detection methods are crucial for food safety.
- Existing detection methods can be time-consuming or lack specificity.
Purpose of the Study:
- To develop a rapid and specific method for detecting Clostridium perfringens in food.
- To utilize 16S ribosomal DNA (rDNA) sequences for highly specific primer design.
- To validate the method's sensitivity and specificity against various bacterial species and food matrices.
Main Methods:
- Design of polymerase chain reaction (PCR) primers targeting the 16S rRNA gene of Clostridium perfringens.
- Sequence alignment using GenBank database for primer specificity.
- Testing the PCR assay with pure cultures of Clostridium perfringens and other bacterial species.
- Validation using artificially contaminated chicken drumstick samples.
Main Results:
- The developed PCR method specifically detected all tested Clostridium perfringens strains.
- No cross-reactivity was observed with 11 other Clostridium species and 38 other common bacterial species.
- As few as two cells of Clostridium perfringens in pure culture were detectable.
- The PCR amplification was completed in just 30 minutes.
- Positive results were obtained from chicken drumstick samples inoculated with as few as 20 cells of Clostridium perfringens.
Conclusions:
- The 16S rDNA-based PCR assay provides a rapid, specific, and sensitive method for Clostridium perfringens detection in food.
- This method can effectively identify Clostridium perfringens contamination in food products.
- The assay is robust, with high bacterial loads of other species not interfering with detection.