Detection of norovirus and indicator organisms on fresh produce

Abstract

Food borne illness is a major problem around the world. Recently, more food borne outbreaks involve produce as the vehicle and viruses as the source of contamination. Norovirus is a common food borne viral pathogen. Genetic diversity among the viruses has made detection difficult. Due to the difficulties in detection, the norovirus is an ideal candidate for having an indicator organism. FRNA bacteriophages share several similarities with enteric viruses and would be an ideal candidate. In this study, we evaluated reverse transcriptase polymerase chain reaction (RT-PCR) detection of norovirus and evaluated using FRNA bacteriophages, E. coli, and Enterococcus as indicator organisms for the virus on produce. Of the five RT-PCR methods tested, only two worked with both controls. Of the 180 produce samples tested, 37.2% were positive for FRNA bacteriophage, 17.2% were positive for Enterococcus, and 0% were positive for E. coli. We conclude that RT-PCR is not an efficient method for screening norovirus on produce and including FRNA bacteriophages as indicator organisms for viruses may help decrease outbreaks.