An 8-hour system for Salmonella detection with immunomagnetic separation and homogeneous time-resolved fluorescence PCR.
We describe a system consisting of rapid sample enrichment and homogeneous end-point PCR analysis that enables the detection of Salmonella in various food matrices in 8 h. Sample preparation starts with 6 h enrichment step in supplemented broth, after which Salmonella cells are collected with immunomagnetic particles. The particles are washed and dispensed to ready-to-use PCR reaction vessels, which contain dried assay-specific reagents and an internal amplification control. PCR is performed with a novel instrument platform utilising the sensitive label technology of time-resolved fluorometry. Qualitative assay results are automatically interpreted and available in 45 min after sample addition. The overall accuracy, sensitivity and specificity of the Magda CA Salmonella system were 99.1%, 98.4% and 100.0%, respectively, based on the evaluation of 107 samples (beef, pork, poultry and ready-to-eat meals) artificially contaminated with sub-lethally injured Salmonella cells.
Hagren
Virve
V
Abacus Diagnostica Ltd., Tykistökatu 4D, FI-20520 Turku, Finland. virve.hagren@abacusdiagnostica.com
von Lode
Piia
P
Syrjälä
Anniina
A
Korpimäki
Teemu
T
Tuomola
Mika
M
Kauko
Otto
O
Nurmi
Jussi
J
D001331:Automation; D005453:Fluorescence; D005470:Fluorometry / Q000379:methods* / Q000592:standards; D005506:Food Contamination / Q000032:analysis*; D005784:Gene Amplification; D018189:Immunomagnetic Separation / Q000379:methods* / Q000592:standards; D016133:Polymerase Chain Reaction / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D012475:Salmonella / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013997:Time Factors