Comparison of viral elution-concentration methods for recovering noroviruses from deli meats

This study aimed to assess viral elution-concentration methods for recovering noroviruses from deli meats. Spiking experiments were conducted to evaluate the recovery success rates and recovery efficiencies of human norovirus (NoV) GI and GII and murine norovirus 1 (MNV-1) using polyethylene glycol (PEG 6000) precipitation, skimmed milk flocculation (SMF), TRIzol^® reagent, and a combination of PEG/TRIzol^® and SMF/TRIzol^® methods. Molecular analysis using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) revealed TRIzol^® as the best method to be used for viral recovery from ham with medium recovery rates of 37.6% for NoV GI and 50.1% for NoV GII. Viral recovery from turkey meat showed medium recovery rates of 14.4% for NoV GI and 8.9% for NoV GII. For MNV-1, the rates varied from 0.5% to 80.8% not only according to the matrix but also with the associated virus and its inoculum (NoV GI or GII). The monitoring of commercial samples obtained in the Great Metropolitan region of Rio de Janeiro in order to demonstrate the occurrence of NoV GI and GII contamination in both matrices was also performed in 60 samples. NoV GI or GII were not detected in any samples, while MNV-1 used as the sample process control viruswas successfully recovered in 100% of samples.