Evaluation of a virus recovery method for detecting rotavirus on chicory

PREZ, VE; MARTÍNEZ, LC; MASACHESSI, G; GIORDANO, MO; RÉ, VE; PAVAN, JV; NATES, SV; BARRIL, PA

Salta

Simposio; III Simposio Latinoamericano de Virología Ambiental; 2016

Because food may contain rotaviruses (RV) in low numbers and only a few virus particles can cause illness, highly sensitive detection methods are needed. This study aimed to evaluate a virus recovery method based on polyethylene glycol (PEG) precipitation for detecting RV from chicory. Samples (40 g) were decontaminated with NaClO 10% and UV radiation previous to being artificially contaminated with 100 µl of a RV vaccine suspension (3200 gc/100µL). Virus recovery was conducted using an elution suspension of beef extract/glycine with 4 different treatments: i) uncut chicory and 1hr elution; ii) uncut chicory and 2hr elution; iii) cut chicory and 1hr elution, and iv) cut chicory and 2hr elution, followed by PEG precipitation. Each treatment was tested 4 times. The sensitivity of the best recovery method was analyzed by contaminating chicory samples with 5 different RV amounts (0.1, 1, 10, 25 and 50 ul of RV vaccine). Each amount was tested twice. RV quantification was performed by qPCR with TaqMan® probe. The mean RV recovery rates according to the treatments were i) 16%, ii) 47%, iii) 52% and iv) 63% and the limit of detection was 5 genome copies. Cutting chicory and longer elution improve the viral recovery method, which proved to be suitable for detecting low amounts of RV on chicory.