Detection and genotyping of enteric foodborne viruses in ready-to-eat leafy vegetables and berries from Córdoba, Argentina

Abstract

The global consumption of ready-to-eat (RTE) leafy green vegetables and berries has risen as consumers perceive them as safe and nutritious options. However, these foods have also been identified as sources of enteric viruses that infect the human gastrointestinal system, which are then excreted and can spread through the fecal-oral route. In Argentina, there is limited evidence on the detection of enteric viruses in food, and no legislation currently requires their detection in frozen or fresh produce intended for domestic consumption. This study aimed to identify and characterize five foodborne viruses with high and low health impact (norovirus, hepatitis A virus, hepatitis E virus, rotavirus, and adenovirus) in berries and RTE leafy vegetables marketed in central Argentina. A total of 242 samples (145 berries and 97 leafy greens) were collected from retail sources in Córdoba and processed according to ISO 15216-2, 2019 standard. Viral detection was performed by qPCR or RT-qPCR, followed by viral characterization through specific RT-PCR assays or Sanger sequencing. Results indicate that 4.2 % (6/145) of berry samples, primarily frozen strawberries, tested positive for norovirus or rotavirus, while 10.3 % (10/97) of leafy green samples were positive for norovirus, rotavirus and adenovirus. Genotyping identified the same genotypes as those associated with local gastroenteritis outbreaks, and phylogenetic analysis showed that the strains were closely related. The absence of hepatitis A and E viruses suggests limited transmission of these pathogens through these foods. This study highlights the need to strengthen hygiene and monitoring protocols for RTE products, as viral contamination poses potential health risks to consumers, underscoring a critical area for improving food safety.