Related Experiment Videos
Rapid detection of salmonellae in poultry with the magnetic immuno-polymerase chain reaction assay
A C Fluit1, M N Widjojoatmodjo, A T Box
1Eijkman-Winkler Laboratory for Medical Microbiology, University Hospital Utrecht, The Netherlands.
Abstract:
Rapid detection of salmonellae in chicken meat was accomplished by using the magnetic immuno-polymerase chain reaction assay (MIPA). A direct polymerase chain reaction assay performed with chicken meat spiked with Salmonella typhimurium resulted in poor sensitivity (approximately 10(7) CFU/g of meat). The use of immunoseparation with a Salmonella serogroup B-specific monoclonal antibody improved the sensitivity, but enrichment was required for the detection of low levels of contamination. Enrichment for 6 h in either buffered peptone water, lactose broth containing tergitol-7, or selenite-cystine broth resulted in the detection of an initial inoculum of 100 CFU per g of meat. Enrichment of the salmonellae present on 25 g of spiked chicken meat for 24 h in either buffered peptone water or selenite-cystine broth before detection by the MIPA yielded a detection limit of approximately 0.1 CFU/g of meat. A detection limit of approximately 1 CFU/g of meat was obtained when the spiked meat was stored at -20 degrees C before enrichment for 24 h and analysis with the MIPA. Although the MIPA was developed for S. typhimurium, a MIPA in which a panel of six monoclonal antibodies specific for Salmonella serogroups A through E was used detected the presence of 0.1 CFU of Salmonella enteritidis per g of chicken meat. These data indicate that the method is applicable to other commonly isolated serotypes.
Insights
A novel magnetic immuno-polymerase chain reaction assay (MIPA) enables rapid salmonellae detection in chicken meat. This method significantly improves sensitivity, achieving detection limits as low as 0.1 CFU/g for enhanced food safety.
Area of Science:
- Food Microbiology
- Molecular Biology
- Immunology
Background:
- Salmonellae contamination in chicken meat poses a significant food safety risk.
- Traditional detection methods often lack the required speed and sensitivity for effective control.
Purpose of the Study:
- To develop and validate a rapid and highly sensitive method for detecting salmonellae in chicken meat.
- To assess the efficacy of the magnetic immuno-polymerase chain reaction assay (MIPA) for food safety applications.
Main Methods:
- Utilized magnetic immuno-polymerase chain reaction assay (MIPA) combined with immunoseparation using Salmonella serogroup-specific monoclonal antibodies.
- Investigated various enrichment strategies (e.g., buffered peptone water, selenite-cystine broth) and incubation times.
- Evaluated detection limits with spiked chicken meat samples under different conditions, including pre-enrichment storage.
Main Results:
- Direct polymerase chain reaction (PCR) showed poor sensitivity (10^7 CFU/g).
- MIPA with immunoseparation and 6-hour enrichment achieved a detection limit of 100 CFU/g.
- 24-hour enrichment with MIPA yielded a detection limit of approximately 0.1 CFU/g.
- The method demonstrated applicability to various Salmonella serogroups, including Salmonella enteritidis.
Conclusions:
- The MIPA offers a rapid and sensitive approach for salmonellae detection in chicken meat.
- Optimized enrichment protocols significantly enhance the assay's sensitivity for low-level contamination.
- The MIPA is a promising tool for improving food safety and surveillance of Salmonella in poultry products.