Purpose: The aim of this study was to evaluate four physical methods and seven elution buffers using a norovirus surrogate on three food matrices.
Methods: The four methods consisted of different combinations of pipetting, vortex mixing, sonication and filtering the buffer through a centrifugation/filtration device (Amicon). Sliced turkey breast, strawberries and lettuce were experimentally spiked with murine norovirus. The viruses were recovered after treatment and the percentage of virus recovered from the surface was determined by real-time RT-PCR.
Results: Less than 5 % of adherent virus was recovered from strawberries regardless of method or elution buffer and the best result was obtained using an elution buffer containing beef extract. Elution buffers containing 1 mol/L NaCl were the most effective on sliced turkey breast, with the sonication + pipetting + Amicon and vortex mixing + Amicon methods providing between 20 % and 60 % recovery. The latter method combined with 1 mol/L NaCl was particularly effective on lettuce.
Significance: These results will help to guide the choice of methods and elution buffers to use for a given food matrix for the purpose of detecting norovirus during outbreaks of foodborne gastroenteritis.