Journal article
A rapid and direct real time PCR-based method for identification of Salmonella spp
The aim of this work was the validation of a rapid, real-time PCR assay based on TaqMan((R)) technology for the unequivocal identification of Salmonella spp. to be used directly on an agar-grown colony. A real-time PCR system targeting at the Salmonella spp. invA gene was optimized and validated through a four times repeated blind experiment performed in two different laboratories including 50 Salmonella spp. with representative strains from each of the 5 different Salmonella subgenera and 30 non-Salmonella strains.
Both parameters DeltaR(n) (fluorescence intensity of template through a normalized reporter value) and C-T (cycle at which the fluorescence intensity achieved a pre-established threshold) were analyzed. Overall mean DeltaR(n) and C-T values for Salmonella strains (2.14 +/- 0.87 and 15.30 +/- 0.90, respectively) were statistically different from values for non-Salmonella strains, allowing the establishment of cut-off DeltaR(n) and C-T values based on 95% confidence intervals that allowed the correct identification of all strains tested in each independent experiment.
The accuracy of this assay in terms of inclusivity and exclusivity was 100%. Moreover, the PCR system proved to be especially convenient because the pre-mix containing all PCR reagents except for the bacterial cells could be kept at -20 degreesC for at least I month before its use. The optimized TaqMan((R)) real-time PCR assay is a useful, simple and rapid method for routine identification of Salmonella spp., irrespective of the particular subgenus.
Language: | English |
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Year: | 2003 |
Pages: | 381-390 |
ISSN: | 01677012 and 18728359 |
Types: | Journal article |
DOI: | 10.1016/S0167-7012(03)00071-X |
ORCIDs: | Hoorfar, Jeffrey |