Norovirus Persistence in Oysters to Prolonged Commercial Purification

Depuration is generally the main treatment employed for bivalve mollusks harvested from contaminated sites. Commercial depuration has demonstrated to be effective for removal of bacterial pathogens, although it probably provides only limited efficacy against human enteric viruses. We evaluated the q...

Full description

Bibliographic Details
Published in:Pathogens
Main Authors: Roberta Battistini, Chiara Masotti, Valeria Listorti, Elisabetta Suffredini, Cristiana Maurella, Aitor Garcia-Vozmediano, Erica Costa, Francesco Iacona, Mino Orlandi, Carlo Ercolini, Laura Serracca
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2021
Subjects:
R
Online Access:https://doi.org/10.3390/pathogens10080944
https://doaj.org/article/31ccd794cab146af9ae4c20fc21ee4e1
Description
Summary:Depuration is generally the main treatment employed for bivalve mollusks harvested from contaminated sites. Commercial depuration has demonstrated to be effective for removal of bacterial pathogens, although it probably provides only limited efficacy against human enteric viruses. We evaluated the quantitative reduction of norovirus (NoV) genogroups I and II in naturally contaminated oysters after 1, 4, and 9 days of depuration. The process was conducted in an authorized depuration plant, and NoV concentration was determined by RT-qPCR according to ISO 15216-1:2017 method. Regardless of the NoV genogroup, our results showed no significant reduction in NoV concentration after 1 day of depuration. Higher mean reduction (68%) was obtained after 4 days of treatment, while no further increase was observed after 9 days. Overall, reduction was highly variable, and none of the trials showed statistically significant reduction in NoV RNA concentration at the end of each depuration period. Indeed, NoV concentration remained high in 70% of samples even after 9 days of depuration, with values ranging between 4.0 × 10 2 and 2.3 × 10 4 g.c./g. These results indicate that an extension of commercial depuration time does not appear to be effective for reducing or eliminating NoV in oysters.