In-house validation of a real-time PCR method for rapid detection of<Emphasis Type="Italic"> Salmonella</Emphasis>
ssp. in food products |
| |
Authors: | Dietrich?M?de Roger?Petersen Klaus?Trümper Regine?Stark Email author" target="_blank">Lutz?GrohmannEmail author |
| |
Affiliation: | (1) Landesamt für Verbraucherschutz Sachsen-Anhalt Dezernat 33, Freiimfelder Str. 66/68, 06112 Halle, Germany;(2) GeneScan Analytics GmbH, Warthestraße 21, 14513 Teltow bei Berlin, Germany;(3) CONGEN Biotechnolgy GmbH, 10 Robert Roessle Straße, 13125 Berlin, Germany |
| |
Abstract: | A real-time polymerase chain reaction (PCR) method for Salmonella ssp. detection in food samples has been developed and validated in-house. The specificity of the assay was confirmed by tests with 295 different
Salmonella strains, including four strains of Salmonella bongori. When tested with extracted Salmonella DNA the lowest detected amount was found to be 5 fg, which is equivalent to approximately one genome copy. The detection limit was further determined by artificial contamination of minced meat with S. Typhimurium cells and of pastry with S. enteritidis using the most probable number approach for cell dose dilutions. It was calculated that even one colony forming unit of Salmonella was still detectable in 25 g food after enrichment culture for 18 h. An additional PCR system for internal positive control, which was included in each reaction and detected in parallel via another reporter fluorescence dye, has no negative impact on the sensitivity of the assay. The method was evaluated with 1,293 naturally contaminated food samples and compared to the conventional cultural method. Of 55 positive PCR samples, 45 were confirmed by the cultural method. The statistical comparison revealed a correlation of 99.2% for specificity, of 100% for sensitivity and of 99.2% for trueness. The results of the comparative analysis and the advantages of the real-time PCR method for detection of Salmonella ssp. under routine laboratory conditions are discussed. |
| |
Keywords: | Salmonella Detection Real-time polymerase chain reaction Food products Method validation |
本文献已被 SpringerLink 等数据库收录! |
|